SYNTHESIS OF BIS(ACYL)PHOSPHINES BY ACTIVATION OF UNREACTIVE METAL PHOSPHIDES

20200115402 ยท 2020-04-16

    Inventors

    Cpc classification

    International classification

    Abstract

    The present invention refers to a process for the preparation of a mono(acyl)phosphine of the general formula (I) and/or a bis(acyl)phosphine of the general formula (II), wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylaryl-sulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NIIR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5-or 6-membered heterocyclic ring; R.sub.6 is H or R.sub.6 is replaced by an alkaline earth metal cation or a mixed alkali metal/alkaline earth metal cation; Formula (II) wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or .sub.NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N- containing 5- or 6-membered heterocyclic ring; as well as the mono(acyl)phosphine and/or bis(acyl)phosphine obtained by the process.

    ##STR00001##

    Claims

    1. A process for the preparation of a mono(acyl)phosphine of the general formula I and/or a bis(acyl)phosphine of the general formula II, ##STR00024## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring; R.sub.6 is H or R.sub.6 is replaced by an alkaline earth metal cation or a mixed alkali metal/alkaline earth metal cation; ##STR00025## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring; the process comprising the steps of: a) contacting a metal phosphide selected from the group comprising Ca.sub.3P.sub.2, Zn.sub.3P.sub.2, Mg.sub.3P.sub.2, AlP, Fe.sub.3P, Ni.sub.3P.sub.2, Sr.sub.3P.sub.2, Ba.sub.3P.sub.2, Co.sub.3P.sub.2, SCP, Ti.sub.3P.sub.4, Sn.sub.3P.sub.4, WP.sub.2, LaP, Pb.sub.3P.sub.2, BiP, and mixtures thereof or a mixed metal phosphide comprising two or more metal cations, with a chelating agent, b) contacting the mixture obtained in step a) with a compound of the general formula IIIa and/or IIIb, ##STR00026## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 and/or R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are as defined above; Z is selected from halogen, C.sub.1-C.sub.20-alkylcarboxy, C.sub.6-C.sub.12-arylcarboxy, C.sub.1-C.sub.8-alkoxy and C.sub.6-C.sub.12-aryloxy; and c) and acidifying the mixture obtained in step b).

    2. The process according to claim 1, wherein R.sub.1, R.sub.3 and R.sub.5 and/or R.sub.7, R.sub.9 and R.sub.11 are the same.

    3. The process according to claim 2, charactcrizcd in that wherein R.sub.1, R.sub.3 and R.sub.5 and/or R.sub.7, R.sub.9 and R.sub.11 are the same and are selected from linear or branched C.sub.1-C.sub.20-alkyl.

    4. The process according to claim 1, wherein R.sub.2 and R.sub.4 and/or R.sub.8 and R.sub.10 are the same.

    5. The process according to claim 1, wherein R.sub.2 and R.sub.4 and/or R.sub.8 and R.sub.10 are the same and are H.

    6. The process according to claim 1, wherein Z is a halogen selected from fluoro, chloro, bromo and iodo.

    7. The process according to claim 1, wherein the metal phosphide is selected from the group comprising Ca.sub.3P.sub.2, Zn.sub.3P.sub.2, Mg.sub.3P.sub.2, AlP, Fe.sub.3P, and mixtures thereof.

    8. The process according to claim 1, wherein the chelating agent has the capability of complexing cations such as Ca.sup.2+, Zn.sup.2+, Mg.sup.2+, Al.sup.+, Fe.sup.3+and mixtures thereof.

    9. The process according to claim 1, wherein the chelating agent is selected from the group comprising 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), 1,2-dihydroxypropane, 1,3-dihydroxypropane, 1,2-dimethoxypropane, 1,3-dimethoxypropane, glycerol, 1,3-dioxane, 1,4-dioxane, tris(2-aminoethyl)amine, tris[2-(dimethylamino)ethyl]amine, diethylene glycol dimethyl ether (Diglyme), triethylene glycol dimethyl ether (Triglyme), N,N,N,N-tetramethylethylendiamine (TMEDA), ethylenediaminetetraacetic acid (EDTA) and mixtures thereof.

    10. The process according to claim 1, wherein an alcohol is further added into step a).

    11. The process according to claim 1, wherein an additive selected from the group comprising potassium tert-butoxide, trisodium -DL-alanine diacetate, trimethylamine, triethylamine and mixtures thereof, is further added into step a) and/or b).

    12. The process according to claim 1, wherein step a) is carried out at a temperature in the range from 10 to 50 C. and/or step b) is carried out at a temperature in the range from 5 to 50 C.

    13. The process according to claim 1, wherein the process comprises a further step d) of alkylating, alkoxylating, alkenylating, alkenoxylating, arylating, acylating, carboxylating, cycloalkylating, cycloalkoxylating, arylalkoxylating, alkenylarylalkoxylating or hydroxylating and subsequently oxidizing the bis(acyl)phosphine of the general formula II obtained in step c) for obtaining the bis(acyl)phosphine of the general formula IV: ##STR00027## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are as defined above, and R.sub.12 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.1-C.sub.8-acyl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    14. The process according to claim 13, wherein the oxidizing is carried out by using hydrogen peroxide.

    15. The process according to claim 1, wherein the process comprises a further step d) of alkylating, alkoxylating, alkenylating, alkenoxylating, arylating, acylating, carboxylating, cycloalkylating, cycloalkoxylating, arylalkoxylating, alkenylarylalkoxylating or hydroxylating the mono(acyl)phosphine of the general formula I obtained in step c) for obtaining the mono(acyl)phosphine of the general formula V: ##STR00028## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are as defined above, and R.sub.13 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.1-C.sub.8-acyl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    16. A mono(acyl)phosphine of the general formula I and/or a bis(acyl)phosphine of the general formula II, ##STR00029## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring; R.sub.6 is H or R.sub.6 is replaced by an alkaline earth metal cation or a mixed alkali metal/alkaline earth metal cation; ##STR00030## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.18-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring; obtained by a process according to claim 1.

    17. A bis(acyl)phosphine of the general formula IV: ##STR00031## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and R.sub.12 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.3-C.sub.12-aryl, C.sub.1-C.sub.8-acyl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, obtained by a process according to claim 13.

    18. A mono(acyl)phosphine of the general formula V: ##STR00032## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and R.sub.13 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.1-C.sub.8-acyl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, obtained by a process according to claim 15.

    Description

    DETAILED DESCRIPTION OF THE INVENTION

    [0042] A process for the preparation of a mono(acyl)phosphine and/or a bis(acyl)phosphine is provided. It is appreciated that a mono(acyl)phosphine of the general formula I and/or a bis(acyl)phosphine of the general formula II is prepared,

    ##STR00013##

    [0043] wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring;

    [0044] R.sub.6 is H or R.sub.6 is replaced by an alkaline earth metal cation or a mixed alkali metal/alkaline earth metal cation;

    ##STR00014##

    [0045] wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0046] As regards R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 in the general formula I and/or II, it is to be noted that they can be the same or different. Preferably, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0047] The term linear or branched C.sub.1-C.sub.20-alkyl in the meaning of the present invention refers to a linear or branched chain alkyl group having 1 to 20 carbon atoms, and includes, for example, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec. butyl, tert. butyl, n-pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, 2-ethylhexyl, 1,1,3,3-tetramethylbutyl, n-heptyl, 2,4,4 trimethylpentyl, 2-ethylhexyl, octyl, nonyl, decyl, undecyl, dodecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl.

    [0048] The term linear or branched C.sub.2-C.sub.8-alkenyl in the meaning of the present invention refers to a linear or branched chain alkenyl group having 2 to 8 carbon atoms, and includes, for example, ethenyl, propenyl, butenyl, triisobutenyl, pentenyl, hexenyl, heptenyl and octenyl, preferably ethenyl or propenyl. The term alkenyl in the meaning of the present invention includes the cis and trans isomers.

    [0049] The term C.sub.1-C.sub.8-alkoxy in the meaning of the present invention means that the alkoxy moiety has a linear or branched chain alkyl having 1 to 8 carbon atoms, and includes, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tertiary butoxy, pentyloxy, hexyloxy, heptyloxy and octyloxy.

    [0050] The term C.sub.2-C.sub.8-alkenyloxy in the meaning of the present invention means that the alkenyloxy moiety has a linear or branched chain alkenyl having 2 to 8 carbon atoms, and includes, for example, ethenyloxy, propenyloxy, butenyloxy, triisobutenyloxy, pentenyloxy, hexenyloxy, heptenyloxy and octenyloxy.

    [0051] The term C.sub.3-C.sub.8-cycloalkyl in the meaning of the present invention refers to a cyclic alkyl having 3 to 8 carbon atoms, and includes, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl, preferably cyclopentyl and cyclohexyl.

    [0052] The term C.sub.6-C.sub.12-aryl in the meaning of the present invention refers to a group containing one or more 6-membered unsaturated hydrocarbon ring(s), wherein the unsaturation is represented formally by conjugated double bonds and which may optionally be substituted at one or more carbon atoms of such ring(s) by independently selected alkyl groups, and includes, for example, phenyl, naphthyl, methylphenyl, dimethoxyphenyl, 5-isopropyl-2-methylphenyl, methylphenyl and t-butylphenyl, preferably naphthyl.

    [0053] The term C.sub.3-C.sub.8-cycloalkoxy in the meaning of the present invention means that the cycloalkoxy moiety has a cyclic alkyl having 3 to 8 carbon atoms, and includes, for example, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, and cycloheptyloxy, preferably cyclopentyloxy and cyclohexyloxy.

    [0054] The term C.sub.7-C.sub.12-arylalkoxy in the meaning of the present invention means that the alkoxy moiety has a linear or branched chain alkyl having 1 to 8 carbon atoms, preferably 1 or 2 carbon atoms, which is connected to C.sub.6-C.sub.12-aryl.

    [0055] The term C.sub.9-C.sub.15-alkenylarylalkoxy in the meaning of the present invention means that the alkoxy moiety has a linear or branched chain alkyl having 1 to 8 carbon atoms, preferably 1 or 2 carbon atoms, which is connected to C.sub.6-C.sub.12-aryl, preferably C.sub.6-aryl, which is further connected to linear or branched C.sub.2-C.sub.8-alkenyl, preferably C.sub.2- alkenyl. Preferably, the alkoxy and alkenyl moieties are connected in para-position of the aryl moiety.

    [0056] The term C.sub.6-C.sub.12-arylsulfonyl in the meaning of the present invention refers to a sulfonyl moiety having a C.sub.6-C.sub.12-aryl.

    [0057] The term 4-alkylarylsulfonyl in the meaning of the present invention refers to a sulfonyl moiety having a C.sub.6-C.sub.12-aryl, which is connected to a linear or branched C.sub.1-C.sub.20-alkyl. The alkyl moiety is connected in para-position of the aryl moiety.

    [0058] The term halogen in the meaning of the present invention refers to fluoro, chloro, bromo or iodo.

    [0059] Preferably, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.5-alkoxy, C.sub.2-C.sub.5-alkenyloxy, C.sub.3-C.sub.5-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.5-alkoxycarbonyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0060] In one embodiment, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 in the general formula I and/or II are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.5-alkenyl, C.sub.1-C.sub.5-alkoxy, C.sub.2-C.sub.5-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and C.sub.6-C.sub.12-aryl. Preferably, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen and, linear or branched C.sub.1-C.sub.20-alkyl. Most preferably, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H and, linear or branched C.sub.1-C.sub.20-alkyl.

    [0061] Thus, it is preferred that one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is/are H.

    [0062] Additionally or alternatively, it is preferred that one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is/are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1-C.sub.15-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.5-alkyl, e.g. linear C.sub.1-C.sub.5-alkyl. For example, one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is/are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl. It is especially preferred that one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is/are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl.

    [0063] Preferably, R.sub.1, R.sub.3 and R.sub.5 are the same. In this embodiment, R.sub.1, R.sub.3 and R.sub.5 are preferably selected from H, halogen, linear or branched C.sub.1-C.sub.5-alkyl, linear or branched C.sub.2-C.sub.5-alkenyl, C.sub.1-C.sub.5-alkoxy, C.sub.2-C.sub.5-alkenyloxy, C.sub.3-C.sub.5-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.5-alkenyl and C.sub.3-C.sub.5-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. For example, R.sub.1, R.sub.3 and R.sub.5 are the same and are selected from linear or branched C.sub.1-C.sub.8-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0064] In one embodiment, R.sub.1, R.sub.3 and R.sub.5 are the same and are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl. For example, R.sub.1, R.sub.3 and R.sub.5 are the same and are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl. It is especially preferred that R.sub.1, R.sub.3 and R.sub.5 are the same and are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl.

    [0065] In one embodiment, R.sub.1, R.sub.3 and R.sub.5 are the same and are SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl.

    [0066] In one embodiment, R.sub.2 and R.sub.4 are the same. In this embodiment, R.sub.2 and R.sub.4 are preferably selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. Preferably, R.sub.2 and R.sub.4 are selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. For example, R.sub.2 and R.sub.4 are the same and are selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0067] In one embodiment, R.sub.2 and R.sub.4 are the same and are H.

    [0068] It is appreciated that R.sub.2 and R.sub.4 are preferably different from R.sub.1, R.sub.3 and R.sub.5. Thus, if R.sub.2 and R.sub.4 are different from R.sub.1, R.sub.3, and R.sub.5, R.sub.2 and R.sub.4 are preferably the same and are H and R.sub.1, R.sub.3 and R.sub.5 are the same and are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1-C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl. For example, R.sub.2 and R.sub.4 are the same and are H and R.sub.1, R.sub.3 and R.sub.5 are the same and are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl. It is especially preferred that R.sub.2 and R.sub.4 are the same and are H and R.sub.1, R.sub.3 and R.sub.5 are the same and are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl.

    [0069] In one embodiment, R.sub.2 and R.sub.4 are the same and are H and R.sub.1, R.sub.3 and R.sub.5 are the same and are SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl.

    [0070] As regards R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in the general formula II, it is to be noted that they can be the same or different. Preferably, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. More preferably, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15- alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0071] In one embodiment, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in the general formula II are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and C.sub.6-C.sub.12-aryl. Preferably, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen and, linear or branched C.sub.1-C.sub.20-alkyl. Most preferably, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H and, linear or branched C.sub.1-C.sub.20-alkyl.

    [0072] Thus, it is preferred that one or more of R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 is/are H.

    [0073] Additionally or alternatively, it is preferred that one or more of R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 is/are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1-C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl. For example, one or more of R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 is/are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl. It is especially preferred that one or more of R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 is/are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl.

    [0074] Preferably, R.sub.7, R.sub.9 and R.sub.11 are the same. In this embodiment, R.sub.7, R.sub.9 and R.sub.11 are preferably selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. Preferably, R.sub.7, R.sub.9 and R.sub.11 are selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. For example, R.sub.7, R.sub.9 and R.sub.11 are the same and are selected from linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0075] In one embodiment, R.sub.7, R.sub.9 and R.sub.11 are the same and are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1-C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl. For example, R.sub.7, R.sub.9 and R.sub.11 are the same and are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl. It is especially preferred that R.sub.7, R.sub.9 and R.sub.11 are the same and are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl.

    [0076] In one embodiment, R.sub.7, R.sub.9 and R.sub.11 are the same and are SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl.

    [0077] In one embodiment, R.sub.8 and R.sub.10 are the same. In this embodiment, R.sub.8 and R.sub.10 are preferably selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. Preferably, R.sub.8 and R.sub.10 are selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. For example, R.sub.8 and R.sub.10 are the same and are selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0078] In one embodiment, R.sub.8 and R.sub.10 are the same and are H.

    [0079] It is appreciated that R.sub.8 and R.sub.10 are preferably different from R.sub.7, R.sub.9 and R.sub.11. Thus, if R.sub.8 and R.sub.10 are different from R.sub.7, R.sub.9 and R.sub.11, R.sub.8 and R.sub.10 are preferably the same and are H and R.sub.7, R.sub.9 and R.sub.11 are the same and are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1-C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl. For example, R.sub.8 and R.sub.10 are the same and are H and R.sub.7, R.sub.9 and R.sub.11 are the same and are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl. It is especially preferred that R.sub.8 and R.sub.10 are the same and are H and R.sub.7, R.sub.9 and R.sub.11 are the same and are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl.

    [0080] In one embodiment, R.sub.8 and R.sub.10 are the same and are H and R.sub.7, R.sub.9 and R.sub.11 are the same and are SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloal kyl.

    [0081] As regards R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in general formula II, it is to be noted that they can be the same or different. Preferably, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.1.sub.5 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0082] In one embodiment, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in the general formula II are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and C.sub.6-C.sub.12-aryl. Preferably, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, .sup.R8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen and, linear or branched C.sub.1-C.sub.20-alkyl. Most preferably, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H and, linear or branched C.sub.1-C.sub.20-alkyl.

    [0083] In one embodiment, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in general formula II are the same. In this embodiment, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are preferably H.

    [0084] Alternatively, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in general formula II are different.

    [0085] It is preferred that one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in general formula II is/are H.

    [0086] Additionally or alternatively, it is preferred that one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in general formula II is/are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1-C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl. For example, one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 is/are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl. It is especially preferred that one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in general formula II is/are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl.

    [0087] Preferably, R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 in general formula II are the same. In this embodiment, R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 are selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. Preferably, R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 are the same and are selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. For example, R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 are the same and are selected from linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0088] In one embodiment, R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 in general formula II are the same and are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl. For example, R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 are the same and are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl. It is especially preferred that R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 are the same and are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl.

    [0089] In one embodiment, R.sub.2, R.sub.4, R.sub.8 and R.sub.10 in general formula II are the same. In this embodiment, R.sub.2, R.sub.4, R.sub.8 and R.sub.10 are selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. For example, R.sub.2, R.sub.5, R.sub.8 and R.sub.10 are the same and are selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0090] In one embodiment, R.sub.2, R.sub.4, R.sub.8 and R.sub.10 are the same and are H.

    [0091] It is appreciated that R.sub.2, R.sub.4, R.sub.8 and R.sub.10 are preferably different from R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11. Thus, if R.sub.2, R.sub.4, R.sub.8 and R.sub.10 are different from R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11, R.sub.2, R.sub.4, R.sub.8 and R.sub.10 are preferably the same and are H and R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 are the same and are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl. For example, R.sub.2, R.sub.4, R.sub.8 and R.sub.10 are the same and are H and R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 are the same and are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl. It is especially preferred that R.sub.2, R.sub.4, R.sub.8 and R.sub.10 are the same and are H and R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 are the same and are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl.

    [0092] As regards R.sub.6 in general formula I, it is to be noted that R.sub.6 is H. Alternatively, R.sub.6 is replaced by an alkaline earth metal cation or a mixed alkali metal/alkaline earth metal cation, preferably an alkaline earth metal cation.

    [0093] Preferably, R.sub.6 in general formula I is H.

    [0094] The term alkaline earth metal cation in the meaning of the present invention preferably refers to magnesium, calcium or strontium cations, more preferably magnesium or calcium cations and most preferably calcium cations.

    [0095] The term mixed alkali metal/alkaline earth metal cation in the meaning of the present invention preferably refers to sodium magnesium, lithium magnesium, potassium magnesium, sodium calcium, lithium calcium, potassium calcium, sodium strontium lithium strontium or potassium strontium cations, more preferably lithium magnesium or lithium calcium cations and most preferably lithium calcium cations.

    [0096] In one embodiment, the bis(acyl)phosphine of the general formula II is a bis(acyl)phosphine, in which R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 in general formula II are the same and R.sub.2, R.sub.4, R.sub.8 and R.sub.10 are the same. Preferably, R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 in general formula II are the same and are C.sub.1-alkyl and R.sub.2, R.sub.4, R.sub.8 and R.sub.10 are the same and are H.

    [0097] Alternatively, the bis(acyl)phosphine of the general formula II is a bis(acyl)phosphine, in which R.sub.1, R.sub.3 and R.sub.5 in general formula II are the same, R.sub.7, R.sub.9 and R.sub.11 are the same, R.sub.2 and R.sub.4 are the same and R.sub.8 and R.sub.10 are the same. In this embodiment, R.sub.1, R.sub.3 and R.sub.5 in general formula II are different from R.sub.7, R.sub.9 and R.sub.11 and R.sub.2 and R.sub.4 are different from R.sub.8 and R.sub.10. It is thus appreciated that a mixed bis(acyl)phosphine can be prepared by the process of the present invention.

    [0098] Alternatively, the bis(acyl)phosphine of the general formula II is a bis(acyl)phosphine, in which R.sub.1 and R.sub.5 in general formula II are the same, R.sub.7 and R.sub.11 are the same, R.sub.2, R.sub.3 and R.sub.4 are the same and R.sub.8, R.sub.3 and R.sub.10 are the same. In this embodiment, R.sub.1 and R.sub.5 in general formula II are different from R.sub.7 and R.sub.11 and R.sub.2, R.sub.3, R.sub.4, R.sub.8, R.sub.9 and R.sub.10 are the same or different, preferably the same.

    [0099] For example, the bis(acyl)phosphine of the general formula II is a bis(acyl)phosphine, in which R.sub.1 and R.sub.5 in general formula II are the same and are chloro, R.sub.7 and R.sub.11 are the same and are methoxy, R.sub.2, R.sub.3 and R.sub.4 are the same and are H and R.sub.8, R.sub.9 and R.sub.10 are the same and are H.

    [0100] Thus, it is appreciated that the process of the present invention results in the preparation of the mono(acyl)phosphine of the general formula I or the bis(acyl)phosphine of the general formula II. More preferably, a mixture of the mono(acyl)phosphine of the general formula I and the bis(acyl)phosphine of the general formula II is obtained.

    [0101] It is to be noted that the formation of the mono(acyl)phosphine of the general formula I and the bis(acyl)phosphine of the general formula II can be controlled by .sup.31P-NMR spectroscopy.

    [0102] .sup.31P-NMR spectroscopy is well known to the skilled person and he will easily adapt the determination conditions according to his process equipment.

    [0103] It is appreciated that the mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II is prepared by a specific process, namely a process avoiding the use of metallic sodium or lithium in combination with undesirable phosphorus compounds such as white phosphorus, red phosphorus, phosphorus trichloride, alkyl or aryl phosphine, or dialkyl or diaryl phosphine.

    [0104] In particular, the process is characterized in that it comprises the steps of [0105] a) contacting a metal phosphide selected from the group comprising Ca.sub.3P.sub.2, Zn.sub.3P.sub.2, Mg.sub.3P.sub.2, AlP, Fe.sub.3P, Ni.sub.3P.sub.2, Sr.sub.3P.sub.2, Ba.sub.3P.sub.2, Co.sub.3P.sub.2, SCP, Ti.sub.3P.sub.4, Sn.sub.3P.sub.4, WP.sub.2, LaP, Pb.sub.3P.sub.2, BiP, and mixtures thereof or a mixed metal phosphide comprising two or more metal cations, with a chelating agent, [0106] b) contacting the mixture obtained in step a) with a compound of the general formula IIIa and/or IIIb,

    ##STR00015## [0107] wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 and/or R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are as defined above; Z is selected from halogen, C.sub.1-C.sub.20-alkylcarboxy, C.sub.6-C.sub.12-arylcarboxy, C.sub.1-C.sub.8-alkoxy and C.sub.6-C.sub.12-aryloxy; and [0108] c) and acidifying the mixture obtained in step b).

    [0109] Accordingly, in a first step a metal phosphide is contacted with a chelating agent. It is believed that the metal cations of the metal phosphide are complexated by the chelating agent and thus this step advantageously provides a sufficient amount of phosphide anions in the following process step b).

    [0110] A suitable metal phosphide is selected from the group comprising Ca.sub.3P.sub.2, Zn.sub.3P.sub.2, Mg.sub.3P.sub.2, AlP, Fe.sub.3P, Ni.sub.3P.sub.2, Sr.sub.3P.sub.2, Ba.sub.3P.sub.2, Co.sub.3P.sub.2, ScP, Ti.sub.3P.sub.4, Sn.sub.3P.sub.4, WP.sub.2, LaP, Pb.sub.3P.sub.2, BiP, and mixtures thereof or a mixed metal phosphide comprising two or more metal cations. Preferably, the metal phosphide is selected from the group comprising Ca.sub.3P.sub.2, Zn.sub.3P.sub.2, Mg.sub.3P.sub.2, AlP, Fe.sub.3P, and mixtures thereof. More preferably, the metal phosphide is selected from the group comprising Ca.sub.3P.sub.2, Zn.sub.3P.sub.2, Mg.sub.3P.sub.2, AlP and mixtures thereof. Even more preferably, the metal phosphide is selected from the group comprising Ca.sub.3P.sub.2, Zn.sub.3P.sub.2, AlP and mixtures thereof. Most preferably, the metal phosphide is selected from the group comprising Ca.sub.3P.sub.2, Zn.sub.3P.sub.2 and mixtures thereof.

    [0111] It is appreciated that the mixed metal phosphide comprising two or more metal cations comprises two or more, preferably two or three, more preferably two, metal cations from periodic table group 2 through to 15. Suitable examples include, but are not limited to, iron cobalt phosphides such as Fe.sub.0.5Co.sub.0.5P, Fe.sub.0.25Co.sub.0.75P or Fe.sub.0.75Co.sub.0.25P, zirconium niobium phosphides such as Zr.sub.6.45Nb.sub.4.55P.sub.4, and mixtures thereof.

    [0112] It is appreciated that calcium and zinc cations are especially accessible to be complexated by the chelating agent and thus render the phosphide anions more accessible for the following reaction and result in higher yields of the mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II. In one embodiment, the metal phosphide is thus Ca.sub.3P.sub.2. Alternatively, the metal phosphide is thus Zn.sub.3P.sub.2.

    [0113] In view of the above, it is thus essential for the present process that the metal phosphide is contacted with a chelating agent in order to provide a sufficient amount of the phosphide anions for the following reaction. The chelating agent is not restricted to a specific chelating agent. However, it is preferred that the chelating agent has the capability of complexing Ca.sup.2+, Zn.sup.2+, Mg.sup.2+, Al.sup.+, Fe.sup.3+, Ni.sup.+, Sr.sup.2+, Ba.sup.2+, Co.sup.2+, Sc.sup.+, Ti.sup.4+, Sn.sup.4+, W.sup.2+, La.sup.+, Pb.sup.3+, Bi.sup.+, and mixtures thereof. Preferably, the chelating agent has the capability of complexing Ca.sup.2+, Zn.sup.2+, Mg.sup.2+, Al+, Fe.sup.3+ and mixtures thereof, preferably Ca.sup.2+, Zn.sup.2+, Mg.sup.2+, Al.sup.3+ and mixtures thereof, and most preferably Ca.sup.2+, Zn.sup.2+, Al.sup.3+ and mixtures thereof. For example, the chelating agent has the capability of complexing Ca.sup.2+. Alternatively, the chelating agent has the capability of complexing Zn.sup.2+.

    [0114] In one embodiment, the chelating agent is selected from the group comprising 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), 1,2-dihydroxypropane, 1,3-dihydroxypropane, 1,2-dimethoxypropane, 1,3-dimethoxypropane, glycerol, 1,3-dioxane, 1,4-dioxane, tris(2-aminoethyl)amine, tris[2-(dimethylamino)ethyl]amine diethylene glycol dimethyl ether (Diglyme), triethylene glycol dimethyl ether (Triglyme), N,N,N,N-tetramethylethylendiamine (TMEDA), ethylenediaminetetraacetic acid (EDTA) and mixtures thereof. For example, the chelating agent is selected from the group comprising 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), glycerol, diethylene glycol dimethyl ether (Diglyme), triethylene glycol dimethyl ether (Triglyme), N,N,N,N-tetramethylethylendiamine (TMEDA), ethylenediaminetetraacetic acid (EDTA) and mixtures thereof. Preferably, the chelating agent is selected from the group comprising 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), diethylene glycol dimethyl ether (Diglyme), triethylene glycol dimethyl ether (Triglyme) and mixtures thereof. More preferably, the chelating agent is selected from 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), diethylene glycol dimethyl ether (Diglyme) and mixtures thereof. Most preferably, the chelating agent is 1,2-dimethoxyethane (DME) and/or 1,2-diethoxyethane (DEE), e.g. 1,2-dimethoxyethane (DME) or 1,2-diethoxyethane (DEE). In one embodiment, the chelating agent is 1,2-dimethoxyethane (DME).

    [0115] It is preferred that the weight ratio of chelating agent to metal phosphide [chelating agent:metal phosphide] is from 50:1 to 2:1, more preferably from 30:1 to 3:1, even more preferably from 20:1 to 3:1 and most preferably from 10:1 to 3:1.

    [0116] Step a) of the process of the present invention can be carried out over a wide temperature range. It is appreciated that a lower temperature in step a) results in a slower complexating of the metal cations by the chelating agent but improves the overall provision of phosphide anions. Thus, in order to obtain a sufficient amount of phosphide anions for the following reaction in step b) it is preferred that the process is carried out at a temperature in the range from 10 to 50 C., preferably in the range from 12 to 40 C., more preferably in the range from 15 to 30 C., and most preferably in the range from 15 to 28 C. For example, step a) is carried out at about room temperature, i.e. a temperature of about 21 C.2 C.

    [0117] In one embodiment, process step a) is carried out in the absence of further additives. This is preferably the case if the chelating agent is liquid as such, e.g. 1,2-dimethoxyethane (DME). Alternatively, process step a) is carried out in the presence of one or more additives. For example, an additive selected from the group comprising potassium tert-butoxide, trisodium -DL-alanine diacetate, trimethylamine, trimethylamine and mixtures thereof, can be added into step a).

    [0118] Additionally or alternatively, an alcohol can be further added into step a). The addition of an alcohol is advantageous in order to control the protonation of the metal phosphide and thus renders the metal phosphide more accessible (i.e. reactive) for the following reaction in process step b).

    [0119] If an alcohol is added into step a), the alcohol is preferably selected from the group comprising methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, tert-butanol, n-amyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 3-methyl-3-pentanol, ethylenglycol, 1,2,3-propantriol, ethanolamine, diethanolamine, triethanolamine and mixtures thereof. The overall yield is further improved if a sterically hindered alcohol is added. Thus, the alcohol is especially selected from the group comprising tert-butanol, sec-amyl alcohol, tert-amyl alcohol, 3-methyl-3-pentanol and mixtures thereof. Most preferably, the alcohol is tert-butanol, tert-amyl alcohol, 3-methyl-3-pentanol and mixtures thereof. For example, the alcohol is tert-amyl alcohol or 3-methyl-3-pentanol.

    [0120] If an alcohol is added into step a), the alcohol is preferably added at the end of step a).

    [0121] Process step a) is preferably carried out under mixing the components, i.e. the metal phosphide, chelating agent and optional additives and alcohol. The skilled person will adapt the mixing conditions (such as the configuration of mixing tools and mixing speed) according to his process equipment.

    [0122] The following process step b) is carried out in that the mixture obtained in step a) is contacted with a compound of the general formula IIIa and/or IIIb,

    ##STR00016##

    [0123] wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 and/or R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are as defined above; Z is selected from halogen, C.sub.1-C.sub.20-alkylcarboxy, C.sub.6-C.sub.12-arylcarboxy, C.sub.1-C.sub.8-alkoxy and C.sub.6-C.sub.12-aryloxy.

    [0124] With regard to the definition of the R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in general formula IIIa and/or IIIb and preferred embodiments thereof, reference is made to the statements provided above when discussing the technical details of the mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II obtained by the process of the present invention.

    [0125] As regards Z in in general formula IIIa and/or IIIb, it is appreciated that Z is selected from halogen, C.sub.1-C.sub.20-alkylcarboxy, C.sub.6-C.sub.12-arylcarboxy, C.sub.1-C.sub.8-alkoxy and C.sub.6-C.sub.12-aryloxy. Preferably, Z is a halogen. More preferably, Z is selected from fluoro, chloro, bromo and iodo, even more preferably chloro, bromo and iodo, still more preferably chloro and bromo. Most preferably, Z is chloro.

    [0126] The term C.sub.1-C.sub.20-alkylcarboxy in the meaning of the present invention means that the carboxy moiety has a linear or branched chain alkyl having 1 to 20 carbon atoms, and includes, for example, methylcarboxy, ethylcarboxy, propylcarboxy, isopropylcarboxy, n-butylcarboxy, isobutylcarboxy, sec. butylcarboxy, tert. butylcarboxy, n-pentylcarboxy, isopentyl carboxy, neopentylcarboxy, hexylcarboxy, heptylcarboxy, octylcarboxy, 2-ethylhexylcarboxy, 1,1,3,3-tetramethylbutylcarboxy, n-heptylcarboxy, 2,4,4-tri methyl pentylcarboxy, 2-ethyl hexylcarboxy, octylcarboxy, nonylcarboxy, decylcarboxy, undecylcarboxy, dodecylcarboxy, tetradecylcarboxy, pentadecylcarboxy, hexadecylcarboxy, heptadecylcarboxy, octadecylcarboxy, nonadecylcarboxy and eicosylcarboxy. Accordingly, Z forms together with the carbonyl group of the compound of the general formula IIIa and/or IIIb an anhydride group.

    [0127] The term C.sub.6-C.sub.12-arylcarboxy in the meaning of the present invention means that the carboxy moiety has a C.sub.6-C.sub.12-aryl, and includes, for example, phenylcarboxy, naphthylcarboxy, methylphenylcarboxy, dimethoxyphenylcarboxy, 5-isopropyl-2-methylphenylcarboxy, methylphenylcarboxy and t-butylphenylcarboxy, preferably naphthylcarboxy. Accordingly, Z forms together with the carbonyl group of the compound of the general formula IIIa and/or IIIb an anhydride group.

    [0128] The term C.sub.1-C.sub.8-alkoxy in the meaning of the present invention means that the alkoxy moiety has a linear or branched chain alkyl having 1 to 8 carbon atoms, and includes, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tertiary butoxy, pentyloxy, hexyloxy, heptyloxy and octyloxy. Accordingly, Z forms together with the carbonyl group of the compound of the general formula IIIa and/or IIIb an ester group.

    [0129] The term C.sub.6-C.sub.12-aryloxy in the meaning of the present invention means that the aryloxy moiety has a C.sub.6-C.sub.12-aryl. Accordingly, Z forms together with the carbonyl group of the compound of the general formula IIIa and/or IIIb an ester group.

    [0130] Thus, in one embodiment the compound of the general formula IIIa is a compound wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and C.sub.6-C.sub.12-aryl and Z is chloro. Preferably, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen and, linear or branched C.sub.1-C.sub.20-alkyl and Z is chloro. Most preferably, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H and linear or branched C.sub.1-C.sub.20-alkyl and Z is chloro.

    [0131] Thus, it is preferred that one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is/are H and Z is chloro. Additionally or alternatively, it is preferred that one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is/are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1-C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl and Z is chloro. For example, one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is/are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl, and Z is chloro. It is especially preferred that one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is/are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl, and Z is chloro.

    [0132] Preferably, R.sub.1, R.sub.3 and R.sub.5 are the same and Z is chloro. In this embodiment, R.sub.1, R.sub.3 and R.sub.5 are preferably selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro. Preferably, R.sub.1, R.sub.3 and R.sub.5 are selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro. For example, R.sub.1, R.sub.3 and R.sub.5 are the same and are selected from linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro.

    [0133] In one embodiment, R.sub.1, R.sub.3 and R.sub.5 are the same and are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1-C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl, and Z is chloro. For example, R.sub.1, R.sub.3 and R.sub.5 are the same and are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl, and Z is chloro. It is especially preferred that R.sub.1, R.sub.3 and R.sub.5 are the same and are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl, and Z is chloro.

    [0134] In one embodiment, R.sub.2 and R.sub.4 are the same and Z is chloro. In this embodiment, R.sub.2 and R.sub.4 are preferably selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro. Preferably, R.sub.2 and R.sub.4 are selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro. For example, R.sub.2 and R.sub.4 are the same and are selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro.

    [0135] In one embodiment, R.sub.2 and R.sub.4 are the same and are H, and Z is chloro.

    [0136] It is appreciated that R.sub.2 and R.sub.4 are preferably different from R.sub.1, R.sub.3 and R.sub.5. Thus, if R.sub.2 and R.sub.4 are different from R.sub.1, R.sub.3, and R.sub.5, R.sub.2 and R.sub.4 are preferably the same and are H and R.sub.1, R.sub.3 and R.sub.5 are the same and are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl, and Z is chloro. For example, R.sub.2 and R.sub.4 are the same and are H and R.sub.1, R.sub.3 and R.sub.5 are the same and are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl, and Z is chloro. It is especially preferred that R.sub.2 and R.sub.4 are the same and are H and R.sub.1, R.sub.3 and R.sub.5 are the same and are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl, and Z is chloro.

    [0137] As regards R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in the general formula 111b, it is to be noted that they can be the same or different. Preferably, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro.

    [0138] In one embodiment, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in the general formula IIIb are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and C.sub.6-C.sub.12-aryl, and Z is chloro. Preferably, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen and, linear or branched C.sub.1-C.sub.20-alkyl, and Z is chloro. Most preferably, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H and, linear or branched C.sub.1-C.sub.20-alkyl, and Z is chloro.

    [0139] Thus, it is preferred that one or more of R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 is/are H and Z is chloro.

    [0140] Additionally or alternatively, it is preferred that one or more of R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 is/are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1-C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear CI-C.sub.8-alkyl, and Z is chloro. For example, one or more of R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 is/are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl, and Z is chloro. It is especially preferred that one or more of R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 is/are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl, and Z is chloro.

    [0141] Preferably, R.sub.7, R.sub.9 and R.sub.11 are the same and Z is chloro. In this embodiment, R.sub.7, R.sub.9 and R.sub.11 are preferably selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-0u2-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, SR.sub.4, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro. Preferably, R.sub.7, R.sub.9 and R.sub.11 are selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro. For example, R.sub.7, R.sub.9 and R.sub.11 are the same and are selected from linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro.

    [0142] In one embodiment, R.sub.7, R.sub.9 and R.sub.11 are the same and are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1-C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl, and Z is chloro. For example, R.sub.7, R.sub.9 and R.sub.11 are the same and are linear or branched C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl, and Z is chloro. It is especially preferred that R.sub.7, R.sub.9 and R.sub.11 are the same and are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl, and Z is chloro.

    [0143] In one embodiment, R.sub.8 and R.sub.10 are the same and Z is chloro. In this embodiment, R.sub.8 and R.sub.10 are preferably selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, SR.sub.14, NHR.sub.14 or NR.sub.14Ris with R.sub.14 and Ris being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro. Preferably, R.sub.8 and R.sub.10 are selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro. For example, R.sub.8 and R.sub.10 are the same and are selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and Z is chloro.

    [0144] In one embodiment, R.sub.8 and R.sub.10 are the same and are H and Z is chloro.

    [0145] It is appreciated that R.sub.8 and R.sub.10 are preferably different from R.sub.7, R.sub.9 and R.sub.11. Thus, if R.sub.8 and R.sub.10 are different from R.sub.7, R.sub.9 and R.sub.11, R.sub.8 and R.sub.10 are preferably the same and are H and R.sub.7, R.sub.9 and R.sub.11 are the same and are linear or branched C.sub.1-C.sub.20-alkyl, preferably linear or branched C.sub.1-C.sub.18-alkyl, more preferably linear or branched C.sub.1-C.sub.12-alkyl and most preferably linear C.sub.1-C.sub.8-alkyl, e.g. linear C.sub.1-C.sub.8-alkyl, and Z is chloro. For example, R.sub.8 and R.sub.10 are the same and are H and R.sub.7, R.sub.9 and R.sub.11 are the same and are linear or branched C.sub.1-C.sub.6-alkyl, e.g. linear C.sub.1-C.sub.6-alkyl, preferably linear or branched C.sub.1-C.sub.4-alkyl, e.g. linear C.sub.1-C.sub.4-alkyl, and most preferably linear or branched C.sub.1-C.sub.3-alkyl, e.g. linear C.sub.1-C.sub.3-alkyl, and Z is chloro. It is especially preferred that R.sub.8 and R.sub.10 are the same and are H and R.sub.7, R.sub.9 and R.sub.11 are the same and are C.sub.1- or C.sub.2-alkyl, e.g. C.sub.1-alkyl, and Z is chloro.

    [0146] In one embodiment, the mixture obtained in step a) is contacted with a compound of the general formula IIIa, wherein R.sub.1, R.sub.3 and R.sub.5 are the same and R.sub.2 and R.sub.4 are the same and Z is chloro. Preferably, R.sub.1, R.sub.3 and R.sub.5 in general formula IIIa are the same and are C.sub.1-alkyl and R.sub.2 and R.sub.4 are the same and are H and Z is chloro. It is appreciated that this embodiment specifically results in a mono(acyl)phosphine of the general formula I and/or the corresponding symmetric bis(acyl)phosphine of the general formula II, i.e. R.sub.1, R.sub.3, R.sub.5, R.sub.7, R.sub.9 and R.sub.11 are the same and R.sub.2, R.sub.4, R.sub.8 and R.sub.10 are the same.

    [0147] Alternatively, the mixture obtained in step a) is contacted with a compound of the general formula IIIa and IIIB, in which R.sub.1, R.sub.3 and R.sub.5 in general formula IIIa are the same, R.sub.7, R.sub.9 and R.sub.11 in general formula IIIb are the same, R.sub.2 and R.sub.4 in general formula IIIa are the same and R.sub.8 and R.sub.10 in general formula IIIb are the same and Z is chloro. In this embodiment, R.sub.1, R.sub.3 and R.sub.5 in general formula IIIa are different from R.sub.7, R.sub.9 and R.sub.11 in general formula IIIb and R.sub.2 and R.sub.4 in general formula IIIa are different from R.sub.8 and R.sub.10 in general formula IIIb and Z is chloro. It is thus appreciated that a mixed bis(acyl)phosphine is obtained if compounds of the general formula IIIa and IIIB are added in step b) of the present process.

    [0148] It is preferred that the equivalent weight ratio of the compound of the general formula IIIa and/or IIIB to the metal phosphide added in step a) [IIIa and/or IIIb:metal phosphide] is from 15:1 to 1:1, more preferably from 12:1 to 2:1, even more preferably from 10:1 to 2:1 and most preferably from 8:1 to 2:1.

    [0149] Step b) of the process of the present invention can be carried out over a wide temperature range. Thus, process step b) is preferably carried out at a temperature in the range from 5 to 50 C., preferably in the range from 0 to 40 C., more preferably in the range from 0 to 30 C., and most preferably in the range from 0 to 28 C.

    [0150] It is appreciated that the yield of the mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II obtained by the process can be increased if the temperature in process step b) is below or in the same range (5 C.) as the temperature used in process step a). Thus, it is preferred that step b) is carried out at about room temperature, i.e. a temperature of about 21 C.2 C.

    [0151] In one embodiment, process steps a) and b) are carried out at about room temperature, i.e. a temperature of about 21 C.2 C.

    [0152] Alternatively, process step b) is carried out at a temperature below the temperature used in process step a).

    [0153] In one embodiment, process step b) is carried out without the addition of further additives. Alternatively, one or more additives can be added to process step b). For example, an additive selected from the group comprising potassium tert-butoxide, trisodium -DL-alanine diacetate, trimethylamine, triethylamine and mixtures thereof, can be added into step b).

    [0154] Additionally or alternatively, an alcohol can be added into step b). The alcohol is preferably selected from the group comprising methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, tert-butanol, n-amyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 3-methyl-3-pentanol, ethylenglycol, 1,2,3-propantriol, ethanolamine, diethanolamine, triethanolamine and mixtures thereof. The overall yield is further improved if a sterically hindered alcohol is added. Thus, the alcohol is especially selected from the group comprising tert-butanol, sec-amyl alcohol, tert-amyl alcohol, 3-methyl-3-pentanol and mixtures thereof. Most preferably, the alcohol is tert-butanol, tert-amyl alcohol, 3-methyl-3-pentanol and mixtures thereof. For example, the alcohol is tert-amyl alcohol or 3-methyl-3-pentanol.

    [0155] If an alcohol is added in process step b), the alcohol is preferably added to the mixture of step a) before the compound of the general formula IIIa and/or IIIB is added.

    [0156] Process step b) is preferably carried out under mixing the components, i.e. the mixture obtained in step a), the compound of the general formula IIIa and/or IIIB and optional additives and alcohol. The skilled person will adapt the mixing conditions (such as the configuration of mixing tools and mixing speed) according to his process equipment.

    [0157] Subsequently to step b), the mixture obtained in step b) is acidified in step c). Preferably, step c) is carried out by adding an acid. It is preferred that the acid has a pKa value of below 6, more preferably in the range from 0 to .sub.5, and most preferably in the range from 2 to 5.

    [0158] In one embodiment, the acid is preferably selected from the group comprising hydrochloric acid, acetic acid, propionic acid, butanoic acid, oxalic acid, fumaric acid, benzoic acid, phosphoric acid, sulfuric acid, citric acid and mixtures thereof.

    [0159] It is appreciated that the acid is not restricted to a specific acid, but it is preferred to add a weak acid in order to avoid the unwanted formation of by-products. Thus, the acid is preferably selected from acetic acid, propionic acid, butanoic acid, oxalic acid, fumaric acid, benzoic acid and citric acid, more preferably is acetic acid.

    [0160] It is preferred that the equivalent weight ratio of the compound of the general formula IIIa and/or IIIB to the acid added in step c) [IIIa and/or IIIb:acid] is from 15:1 to 1:1, more preferably from 12:1 to 2:1, even more preferably from 10:1 to 2:1 and most preferably from 8:1 to 2:1.

    [0161] Step c) of the process of the present invention can be carried out over a wide temperature range. Thus, process step b) is preferably carried out at a temperature in the range from 5 to 50 C., preferably in the range from 0 to 40 C., more preferably in the range from 0 to 30 C., and most preferably in the range from 0 to 28 C. However, it is preferred that step c) is carried out at about room temperature, i.e. a temperature of about 21 C.2 C.

    [0162] Subsequent to process step c) of acidifying the mixture obtained in step b), the process may comprise further steps for isolating and/or purifying the obtained mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II.

    [0163] For example, the process may further comprise a step of [0164] i) separating the obtained mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II from the chelating agent, and/or [0165] ii) taking up the obtained mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II in organic solvent and filtering the obtained mixture.

    [0166] In one embodiment, the process further comprises the steps of [0167] i) separating the obtained mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II from the chelating agent, and/or [0168] ii) taking up the obtained mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II in organic solvent and filtering the obtained mixture.

    [0169] Additionally, the process may further comprise a step of drying the obtained mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II.

    [0170] Such steps are well known in the art and will be adapted by the skilled person according to the process conditions and equipment used for carrying out the process of the present invention.

    [0171] In one embodiment, the process comprises a further step d) of alkylating, alkoxylating, alkenylating, alkenoxylating, arylating, acylating, carboxylating, cycloalkylating, cycloalkoxylating, arylalkoxylating, alkenylarylalkoxylating or hydroxylating and oxidizing the bis(acyl)phosphine of the general formula II obtained in step c) for obtaining the bis(acyl)phosphine of the general formula IV

    ##STR00017##

    [0172] wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are as defined above, and R.sub.12 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.1-C.sub.8-acyl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0173] With regard to the definition of the R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in general formula IV and preferred embodiments thereof, reference is made to the statements provided above when discussing the technical details of the mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II obtained by the process of the present invention.

    [0174] As regards R.sub.12 in general formula IV, it is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.1-C.sub.8-acyl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. Preferably, R.sub.12 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.1-C.sub.8-acyl,and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. More preferably, R.sub.12 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl and C.sub.6-C.sub.12-aryl. Most preferably, R.sub.12 is OH or linear or branched C.sub.1-C.sub.20-alkyl. For example, R.sub.12 is OH.

    [0175] The oxidizing is preferably carried out by using hydrogen peroxide.

    [0176] Reactions resulting in the alkylating, alkoxylating, alkenylating, alkenoxylating, arylating, acylating, carboxylating, cycloalkylating, cycloalkoxylating, arylalkoxylating, alkenylarylalkoxylating or hydroxylating and oxidizing of a bis(acyl)phosphine of the general formula II are well known in the art and can be adapted by the skilled person according to the specific reaction and equipment used for carrying out the process of the present invention.

    [0177] Alternatively, the process can comprise a further step d) of alkylating, alkoxylating, alkenylating, alkenoxylating, arylating, acylating, carboxylating, cycloalkylating, cycloalkoxylating, arylalkoxylating, alkenylarylalkoxylating or hydroxylating the mono(acyl)phosphine of the general formula I obtained in step c) for obtaining the mono(acyl)phosphine of the general formula V

    ##STR00018##

    [0178] wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are as defined above, and R.sub.13 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.1-C.sub.8-acyl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring.

    [0179] With regard to the definition of the R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 in general formula V and preferred embodiments thereof, reference is made to the statements provided above when discussing the technical details of the mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II obtained by the process of the present invention.

    [0180] As regards R.sub.13 in general formula V, it is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.1-C.sub.8-acyl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. Preferably, R.sub.13 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.1-C.sub.8-acyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. More preferably, R.sub.13 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl and C.sub.6-C.sub.12-aryl.

    [0181] Reactions resulting in the alkylating, alkoxylating, alkenylating, alkenoxylating, arylating, acylating, carboxylating, cycloalkylating, cycloalkoxylating, arylalkoxylating, alkenylarylalkoxylating or hydroxylating of a mono(acyl)phosphine of the general formula I are well known in the art and can be adapted by the skilled person according to the specific reaction and equipment used for carrying out the process of the present invention.

    [0182] In another aspect, the present invention refers to a mono(acyl)phosphine of the general formula I and/or a bis(acyl)phosphine of the general formula II,

    ##STR00019##

    [0183] wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring;

    [0184] R.sub.6 is H or R.sub.6 is replaced by an alkaline earth metal cation or a mixed alkali metal/alkaline earth metal cation;

    ##STR00020##

    [0185] wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. The mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II is preferably obtained by the process of the present invention.

    [0186] With regard to the definition of the R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in general formula I and/or II and preferred embodiments thereof, reference is made to the statements provided above when discussing the technical details of the mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II obtained by the process of the present invention.

    [0187] In a further aspect, the present invention refers to a bis(acyl)phosphine of the general formula IV

    ##STR00021##

    [0188] wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and R.sub.12 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.1-C.sub.8-acyl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.18-alkenylarylalkoxy and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. The bis(acyl)phosphine of the general formula IV is preferably obtained by the process of the present invention.

    [0189] With regard to the definition of the R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 in general formula IV and preferred embodiments thereof, reference is made to the statements provided above when discussing the technical details of the mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II and the bis(acyl)phosphine of the general formula IV obtained by the process of the present invention.

    [0190] In a further aspect, the present invention refers to a mono(acyl)phosphine of the general formula V

    ##STR00022##

    [0191] wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and are independently selected from H, halogen, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15-alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl, SR.sub.14, NHR.sub.14 or NR.sub.14R.sub.15 with R.sub.14 and R.sub.15 being independently selected from H, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl and C.sub.3-C.sub.8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring, and R.sub.13 is selected from the group comprising OH, linear or branched C.sub.1-C.sub.20-alkyl, linear or branched C.sub.2-C.sub.8-alkenyl, C.sub.1-C.sub.8-alkoxy, C.sub.2-C.sub.8-alkenyloxy, C.sub.3-C.sub.8-cycloalkyl, C.sub.6-C.sub.12-aryl, C.sub.1-C.sub.8-acyl, C.sub.3-C.sub.8-cycloalkoxy, C.sub.7-C.sub.12-arylalkoxy, C.sub.9-C.sub.15- alkenylarylalkoxy, nitro-, C.sub.6-C.sub.12-arylsulfonyl, 4-alkylarylsulfonyl, C.sub.1-C.sub.20-alkylcarboxy, C.sub.1-C.sub.8-alkoxycarbonyl and an O-, S- or N-containing 5- or 6-membered heterocyclic ring. The mono(acyl)phosphine of the general formula V is preferably obtained by the process of the present invention.

    [0192] With regard to the definition of the R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.13 in general formula V and preferred embodiments thereof, reference is made to the statements provided above when discussing the technical details of the mono(acyl)phosphine of the general formula I and/or the bis(acyl)phosphine of the general formula II and the mono(acyl)phosphine of the general formula V obtained by the process of the present invention.

    [0193] The scope and interest of the invention will be better understood based on the following examples which are intended to illustrate certain embodiments of the invention and are non-limitative.

    EXAMPLES

    Example 1:

    [0194] Synthetic Procedure

    [0195] A 100 mL flask was flushed with argon and charged with calcium phosphide (8%, 3.1g, 1.36 mmol, 1 eq.). Dry 1,2-dimethoxyethane (DME) (20 mL) was added to the flask. After stirring the reaction mixture for 15 minutes, 2,4,6-trimethylbenzoyl chloride (1.0 g, 0.909 mL, 5.55 mmol, 4 eq.) was added slowly over a period of 10 minutes at ambient temperature (21 C.). Subsequently, the mixture was stirred for another 17 hours at ambient temperature. A color change from red-brown to greenish yellow was observed, along with an increase of the viscosity of the mixture. This protocol yields the calcium salt Ca[P(COMes).sub.2].sub.2 as the product. This was further treated at room temperature (22 C.) with acetic acid (1.12 g, 19 mmol, 13.7 eq.) which was added dropwise within 10 minutes. The reaction mixture was stirred for another 22 hours at ambient temperature to yield HP(COMes)2 (BAP-H).

    [0196] The solvent DME was removed in vacuo and a yellow solid residue was obtained. The yellow solid was dissolved in dry toluene (75 mL) and filtered over celite in order to remove CaCl.sub.2 and Ca(OAc).sub.2. The filter cake was washed twice with dry toluene (25 mL). After filtration, toluene was removed in vacuo at room temperature (24 C.) for 6 hours and gave 5.4 g of crude BAP-H (3.5% purity based on NMR spectroscopy which corresponds to a yield of 21.3%.

    [0197] The .sup.31P{1H} NMR spectrum shows two signals at =81 and 6 ppm indicating an equilibrium of the protonated phosphine (=6 ppm) and its enol from P-acyl-2-hydroxy-phosphaalkene (=81 ppm) as shown in the following scheme 1:

    ##STR00023##

    [0198] Formula: C.sub.20H.sub.23O.sub.2P

    [0199] Molar mass: 326.37 g/mol

    [0200] .sup.31P NMR (121.5 MHz, C.sub.6D.sub.6) [ppm]=81 (s), 6 (s).

    [0201] .sup.1H NMR (400.13 MHz, C.sub.6D6) [ppm]=2.00 (s, 6H, Mes p-CH.sub.3) 2.33 (s, 12H, Mes o-CH.sub.3), 6.55 (s, 4H, Mes m-H).