PROCESS FOR PRODUCING AROMATIC COMPOUND, AND PALLADIUM COMPLEX

Abstract

A process for producing an aromatic compound in high yield and a palladium complex are provided. The palladium complex is represented by formula (D) or formula (D):

##STR00001##

In formula (D), X represents a chlorine atom, A represents an alkyl group having 1 to 3 carbon atoms, B represents an alkyl group having 4 to 20 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms, R.sup.4 and R.sup.5 each independently represent a hydrogen atom, a fluorine atom, or an alkoxy group having 1 to 20 carbon atoms, and R.sup.6, R.sup.7 and R.sup.8 represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or a heteroaryl group having 4 to 20 carbon atoms.

##STR00002##

In formula (D), X, A, B and R.sup.4 to R.sup.8 are the same as defined above.

Claims

1. A palladium complex represented by the formula (D) or the formula (D): ##STR00038## wherein, X represents a chlorine atom, a bromine atom or an iodine atom, A represents an alkyl group having 1 to 3 carbon atoms, B represents an alkyl group having 4 to 20 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms, R.sup.4 and R.sup.5 each independently represent a hydrogen atom, a fluorine atom, an alkoxy group having 1 to 20 m carbon atoms or a cycloalkoxy group having 5 to 10 carbon atoms, R.sup.6, R.sup.7 and R.sup.8 each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms and optionally having a substituent, or a heteroaryl group having 4 to 20 carbon atoms and optionally having a substituent, wherein the number of carbon atoms of the aryl group and the heteroaryl group does not include the number of carbon atoms of the substituent, wherein the optional substituent is selected from the following Group 1, and wherein all of R.sup.4 to R.sup.8 do not represent a hydrogen atom at the same time; ##STR00039## wherein, X, A, B and R.sup.4 to R.sup.8 are the same as defined above, and the plurality of X, A, B and R.sup.4 to R.sup.8 may be the same or different at each occurrence; Group 1: a fluorine atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an alkylthio group, a cycloalkylthio group, an aryl group, an aryloxy group, an arylthio group, an arylalkyl group, an arylcycloalkyl group, an arylalkenyl group, an arylalkynyl group, a heterocycle group optionally having an alkyl group, a group represented by N(R).sub.2 wherein two R each independently represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a heterocycle group optionally having an alkyl group, a group represented by Si(R).sub.3 wherein R is the same as defined above and three R may be the same or different at each occurrence, an acyl group, a group having a carbon atom-nitrogen atom double bond, an acid imide group, an alkoxycarbonyl group, a cycloalkoxycarbonyl group, an aryloxycarbonyl group, a carboxy group, a cyano group, a nitrile group and a nitro group.

2. The palladium complex according to claim 1, wherein A is a methyl group.

3. The palladium complex according to claim 1, wherein B is an alkyl group having 4 to 20 carbon atoms.

4. The palladium complex according to claim 3, wherein B is an alkyl group having 4 to 6 carbon atoms.

5. The palladium complex according to claim 4, wherein B is a tert-butyl group.

6. The palladium complex according to claim 1, wherein R.sup.4 and R.sup.5 are each a hydrogen atom.

7. A process for producing an aromatic compound comprising a step of reacting a compound represented by the formula (A) with a compound represented by the formula (B) in the presence of a palladium complex represented by the formula (C) or the formula (C) and a base:
Ar.sup.1X.sup.1).sub.m(A) wherein, X.sup.1 represents a group represented by any one of the formula (1) to the formula (12), M represents a group I element, m is 1 or 2, and when a plurality of X.sup.1 are present, the plurality of X.sup.1 may be the same or different, ##STR00040## when m is 1 or 2, Ar.sup.1 represents an aryl group having 6 to 36 carbon atoms and optionally having a substituent, or a heteroaryl group having 4 to 36 carbon atoms and optionally having a substituent; when m is 1, Ar.sup.1 represents an arylene group having 6 to 36 carbon atoms and optionally having a substituent, or a heteroarylene group having 4 to 36 carbon atoms and optionally having a substituent; when m is 2, the number of carbon atoms of these groups does not include the number of carbon atoms of the substituent, the optional substituent is selected from Group 1, the aryl group may be a monovalent group formed by directly linking two or more monocyclic and/or condensed-cyclic aryl groups at each occurrence or by indirectly linking two or more monocyclic and/or condensed-cyclic aryl groups via a hetero atom or a carbonyl group at each occurrence, the heteroaryl group may be a monovalent group formed by directly linking two or more monocyclic and/or condensed-cyclic heteroaryl groups at each occurrence or by indirectly linking two or more monocyclic and/or condensed-cyclic heteroaryl groups via a hetero atom or a carbonyl group at each occurrence, or may be a monovalent group formed by directly linking at least one monocyclic and/or condensed-cyclic heteroaryl group to at least one monocyclic and/or condensed-cyclic aryl group at each occurrence or by indirectly linking at least one monocyclic and/or condensed-cyclic heteroaryl group to at least one monocyclic and/or condensed-cyclic aryl group via a hetero atom or a carbonyl group at each occurrence, the arylene group may be a divalent group formed by directly linking two or more monocyclic and/or condensed-cyclic arylene groups at each occurrence or by indirectly linking two or more monocyclic and/or condensed-cyclic arylene groups via a hetero atom or a carbonyl group at each occurrence and the heteroarylene group may be a divalent group formed by directly linking two or more monocyclic and/or condensed-cyclic heteroarylene groups at each occurrence or by indirectly linking two or more monocyclic and/or condensed-cyclic heteroarylene groups via a hetero atom or a carbonyl group at each occurrence, or may be a divalent group formed by directly linking at least one monocyclic and/or condensed-cyclic heteroarylene group to at least one monocyclic and/or condensed-cyclic arylene group at each occurrence or by indirectly linking at least one monocyclic and/or condensed-cyclic heteroarylene group to at least one monocyclic and/or condensed-cyclic arylene group via a hetero atom or a carbonyl group at each occurrence; Group 1: a fluorine atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an alkylthio group a cycloalkylthio group, an aryl group, an aryloxy group, an arylthio group, an arylalkyl group, an arylcycloalkyl group, an arylalkenyl group, an arylalkynyl group, a heterocycle group optionally having an alkyl group, a group represented by N(R).sub.2 wherein two R each independently represent a hydrogen atom, a hydrocarbon group having 1 to 20 of carbon atoms or a heterocycle group optionally having an alkyl group, a group represented by Si(R).sub.3 wherein R is the same as defined above and three R may be the same or different at each occurrence, an acyl group, a group having a carbon atom-nitrogen atom double bond, an acid imide group, an alkoxycarbonyl group, a cycloalkoxycarbonyl group, an aryloxycarbonyl group, a carboxy group, a cyano group, a nitrile group and a nitro group;
Ar.sup.2X.sup.2).sub.n(B) wherein, X.sup.2 represents a chlorine atom, a bromine atom, an iodine atom, an alkylsulfonyloxy group, an alkylsulfonyloxy group substituted with a fluorine atom, or an arylsulfonyloxy group, and when a plurality of X.sup.2 are present, the plurality of X.sup.2 may be the same or different at each occurrence, n represents 1 or 2, when n is 1, Ar.sup.2 represents an aryl group having 6 to 36 carbon atoms and optionally having a substituent, or a heteroaryl group having 4 to 36 carbon atoms and optionally having a substituent, when n is 2, Ar.sup.2 represents an arylene group having 6 to 36 carbon atoms and optionally having a substituent, or a heteroarylene group having 4 to 36 carbon atoms and optionally having a substituent, wherein the number of carbon atoms of these groups does not include the number of carbon atoms of the substituent, the optional substituent is selected from Group 1, the aryl group may be a monovalent group formed by directly linking two or more monocyclic and/or condensed-cyclic aryl groups at each occurrence or by indirectly linking two or more monocyclic and/or condensed-cyclic aryl groups via a hetero atom or a carbonyl group at each occurrence, the heteroaryl group may be a monovalent group formed by directly linking two or more monocyclic and/or condensed-cyclic heteroaryl groups or by indirectly linking two or more monocyclic and/or condensed-cyclic heteroaryl groups via a hetero atom or a carbonyl group at each occurrence, or may be a monovalent group formed by directly linking at least one monocyclic and/or condensed-cyclic heteroaryl group to at least one monocyclic and/or condensed-cyclic aryl group at each occurrence or by indirectly linking at least one monocyclic and/or condensed-cyclic heteroaryl group to at least one monocyclic and/or condensed-cyclic aryl group via a hetero atom or a carbonyl group at each occurrence, the arylene group may be a divalent group formed by directly linking two or more monocyclic and/or condensed-cyclic arylene groups at each occurrence or by indirectly linking two or more monocyclic and/or condensed-cyclic arylene groups via a hetero atom or a carbonyl group at each occurrence, and the heteroarylene group may be a divalent group formed by directly linking two or more monocyclic and/or condensed-cyclic heteroarylene groups at each occurrence or by indirectly linking two or more monocyclic and/or condensed-cyclic heteroarylene groups via a hetero atom or a carbonyl group at each occurrence, or may be a divalent group formed by directly linking at least one monocyclic and/or condensed-cyclic heteroarylene group to at least one monocyclic and/or condensed-cyclic arylene group at each occurrence or by indirectly at least one monocyclic and/or condensed-cyclic heteroarylene group to at least one monocyclic and/or condensed-cyclic arylene group via a hetero atom or a carbonyl group at each occurrence; ##STR00041## wherein, X represents a chlorine atom, a bromine atom or an iodine atom, A represents an alkyl group having 1 to 3 carbon atoms, R.sup.1 represents an alkyl group having a 1 to 20 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms and optionally having a substituent, or a heteroaryl group having 4 to 20 carbon atoms and optionally having a substituent, and R.sup.2 and R.sup.3 each independently represent an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms, wherein the number of carbon atoms of the aryl group and the heteroaryl group does not include the number of carbon atoms of the substituent and the optional substituent is selected from Group 1; ##STR00042## wherein X, A, R.sup.1, R.sup.2 and R.sup.3 are the same as defined above, and the plurality of X, A, R.sup.1, R.sup.2 and R.sup.3 may be the same or different at each occurrence.

8. The process for producing the aromatic compound according to claim 7, wherein R is an aryl group having 6 to 20 carbon atoms and optionally having a substituent, or a heteroaryl group having 4 to 20 carbon atoms and optionally having a substituent.

9. The process for producing the aromatic compound according to claim 7, wherein R.sup.2 and R.sup.3 each independently represent an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 5 to 6 carbon atoms.

10. The process for producing the aromatic compound according to claim 7, wherein A is a methyl group.

11. The process for producing the aromatic compound according to claim 7, wherein Ar.sup.1 and Ar.sup.2 each independently represent a group selected from the following Group Ar; Group Ar: a monocyclic aryl group, a condensed-cyclic aryl group and a monovalent group formed by directly linking two or more monocyclic aryl groups at each occurrence or by indirectly linking two or more monocyclic aryl groups via a hetero atom or a carbonyl group at each occurrence, a monocyclic heteroaryl group, a condensed-cyclic heteroaryl group and a monovalent group formed by directly linking two or more monocyclic heteroaryl groups at each occurrence or by indirectly linking two or more monocyclic heteroaryl groups via a hetero atom or a carbonyl group at each occurrence, a monocyclic arylene group, a condensed-cyclic arylene group and a divalent group formed by directly linking two or more monocyclic arylene groups at each occurrence or by indirectly linking two or more monocyclic arylene groups via a hetero atom or a carbonyl group at each occurrence, and a monocyclic heteroarylene group, a condensed-cyclic heteroarylene group and a divalent group formed by directly linking two or more monocyclic heteroarylene groups at each occurrence or by indirectly linking two or more monocyclic heteroarylene groups via a hetero atom or a carbonyl group at each occurrence.

12. A palladium complex represented by the formula (C) or the formula (C): ##STR00043## wherein, X represents a chlorine atom, a bromine atom or an iodine atom, A represents an alkyl group having 1 to 3 carbon atoms, R.sup.1 represents an alkyl group having to 20 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms optionally having a substituent, or a heteroaryl group having 4 to 20 carbon atoms optionally having a substituent, and R.sup.2 and R.sup.3 each independently represent an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms, wherein the number of carbon atoms of the aryl group and the heteroaryl group does not include the number of carbon atoms of the substituent, and the optional substituent is selected from Group 1; Group 1: a fluorine atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an alkylthio group, a cycloalkylthio group, an aryl group, an aryloxy group, an arylthio group, an arylalkyl group, an arylcycloalkyl group, an arylalkenyl group, an arylalkynyl group, a heterocycle group optionally having an alkyl group, a group represented by N(R).sub.2 wherein two R each independently represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a heterocycle group optionally having an alkyl group, a group represented by Si(R).sub.3 wherein R is the same as defined above and three R may be the same or different at each occurrence, an acyl group, a group having a carbon atom-nitrogen atom double bond, an acid imide group, an alkoxycarbonyl group, a cycloalkoxycarbonyl group, an aryloxycarbonyl group, a carboxy group, a cyano group, a nitrile group and a nitro group; ##STR00044## wherein X, A, R.sup.1, R.sup.2 and R.sup.3 represent the same meaning as described above, and a plurality of X, A, R.sup.1, R.sup.2 and R.sup.3 may be the same or different at each occurrence, wherein the complex is a catalyst for Suzuki coupling.

13. The palladium complex according to claim 12, wherein R.sup.1 is an aryl group having 6 to 20 carbon atoms optionally having a substituent, or a heteroaryl group having 4 to 20 carbon atoms optionally having a substituent.

14. The palladium complex according to claim 12, wherein R.sup.2 and R.sup.3 each independently represent an alkyl group having 1 to 6 a number of carbon atoms or a cycloalkyl group having 5 to 6 carbon atoms.

15. The palladium complex according to claim 12, wherein A is a methyl group.

Description

EXAMPLES

[0328] The present invention will be illustrated further in detail by examples below, but the present invention is not limited to these examples.

[0329] The yield of the resultant aromatic compound was calculated from the analysis result by gas chromatography (hereinafter, abbreviated as GC in some cases). The analysis conditions for GC are as described below. When the resultant aromatic compound is an aromatic compound comprising a repeating unit represented by the formula (F-4), the compound was analyzed by gel permeation chromatography (hereinafter, abbreviated as GPC), analysis conditions are as described below, and the polystyrene-equivalent weight-average molecular weight (Mw) and number-average molecular weight (Mn) were calculated from the analysis result and these are used as an index for the yield of the aromatic compound.

<GC Analysis Conditions>

[0330] GC measurement apparatus: GC-2010 (manufactured by Shimadzu Corp)

[0331] column: DB-1 film thickness 0.25 m, 3000.25 mm (manufactured by Agilent Technologies)

[0332] temperature of vaporizing chamber: 300 C.

[0333] temperature of detector: 300 C.

[0334] temperature of column: keeping at 40 C. for 3 minutes, then, raising up to 200 C. at 4.5 C./min, subsequently, raising up to 300 C. at 20 C./min, and then, keeping for 1 minute

[0335] injection amount: 1 L

[0336] total flow rate: 13.2 mL/min

[0337] column flow rate: 1.70 mL/min

[0338] split ratio: 5.0

[0339] detection: FID detection

<GPC Analysis Condition>

[0340] GPC measurement apparatus: CTO-10AC (column oven manufactured by Shimadzu Corp), SPD-10A (detector manufactured by Shimadzu Corp)

[0341] column: Shodex KD-806 8.0 mm30 cm (manufactured by SHOWA DENKO K.K.)

[0342] temperature of column: 60 C.

[0343] mobile phase: ortho-dichlorobenzene

[0344] flow rate: 1 mL/min

[0345] detection: visible light detection (wavelength 600 nm)

<NMR Measurement Condition>

[0346] NMR measurement apparatus: AVANCE600 (manufactured by BRUKER) or JNM-ECA400 (manufactured by JEOL) measurement nucleus: H nucleus, P nucleus

Example 1

[0347] A nitrogen atmosphere was prepared in a glass reaction vessel, then, 10.6 mmol of di-tert-butyl(3,5-di-(tert-butyl)phenylphosphonium tetrafluoroborate, 20 mL of diethyl ether and 10.6 mmol of triethylamine were added thereto, followed by stirred at room temperature for 5 minutes. A solid was isolated from the resultant suspended liquid by filtration, and the resultant liquid was added into a glass reaction vessel containing 7.5 mmol of chloromethyl(1,5-cyclooctadiene)palladium(II). The resultant mixture was stirred at room temperature for 30 minutes, then, the resultant reaction solution was added dropwise into 94 mL of hexane. The generated solid was isolated by filtration, then, washed three times with 30 mL of hexane. The resultant solid was dried under reduced pressure, to obtain 2.23 g of chloromethyl(di(tert-butyl) (3,5-di(tert-butyl)phenylphosphine)palladium(II) as a white solid.

##STR00032##

chloromethyl(di(tert-butyl) (3,5-di(tert-butyl)phenylphosphine)palladium(II)

[0348] 1H-NMR ( ppm, CDCl.sub.3 solvent, TMS standard): 7.6 (dd, 2H), 7.4 (d, 1H), 1.5 (d, 18H), 1.3 (s, 18H), 0.7 (d, 3H)

[0349] .sup.31P-NMR ( ppm, CDCl.sub.3 solvent): 77.4

Example 2

[0350] Into a glass reaction vessel equipped with a cooling apparatus were added 0.01 mmol of chloromethyl(tri-tert-butylphosphine)palladium(II), 0.5 mmol of 2-bromo-m-xylene, 0.5 mmol of 2-thiopheneboronic acid, 1.0 mmol of potassium phosphate, 4.5 mL of methanol, 0.5 mL of water, and 0.07 mmol of n-octylbenzene as an internal standard. The resultant mixture was stirred at 0 C. for 3 hours. Two hundred microliters of the resultant reaction mixture was diluted with 5 mL of tetrahydrofuran, then, GC analysis was conducted to find a yield of the desired 2-(2,6-dimethylphenyl)-thiophene of 94%.

##STR00033##

chloromethyl(tri-tert-butylphosphine)palladium(II)

Example 3

[0351] 2-(2,6-dimethylphenyl)-thiophene was obtained in the same manner as in Example 2, except that sodium carbonate was used instead of potassium phosphate in Example 2. Its yield was 91%.

Comparative Example 1

[0352] 2-(2,6-dimethylphenyl)-thiophene was obtained in the same manner as in Example 2, except that [2-(amino-N)(1,1-biphenyl)-2-yl-C]chloro[tri-(tert-butyl)phosphine]palladium(II) was used instead of chloromethyl(tri-tert-butylphosphine)palladium(II) in Example 2. Its yield was 12%.

##STR00034##

[2-(amino-N) (1,1-biphenyl)-2-yl-C]chloro[tri-(tert-butyl)phosphine]palladium(II)

Comparative Example 2

[0353] 2-(2,6-dimethylphenyl)-thiophene was obtained in the same manner as in Example 2, except that [2-(amino-N)(1,1-biphenyl)-2-yl-C]chloro[tri-(tert-butyl)phosphine]palladium(II) was used instead of chloromethyl(tri-tert-butylphosphine)palladium(II) in Example 2 and sodium carbonate was used instead of potassium phosphate in Example 2. Its yield was 75%.

Example 4

[0354] Into a glass reaction vessel equipped with a cooling apparatus were added 0.0025 mmol of chloromethyl(di(tert-butyl) (3,5-di(tert-butyl)phenylphosphine)palladium(II) obtained in Example 1, 0.5 mmol of 2-bromo-m-xylene, 0.5 mmol of 2-thiopheneboronic acid, 1.0 mmol of potassium phosphate, 4.5 mL of tetrahydrofuran, 0.5 mL of water, and 0.07 mmol of n-octylbenzene as an internal standard. The resultant mixture was stirred at 45 C. for 3 hours. Two hundred microliters of the resultant reaction mixture was diluted with 5 mL of tetrahydrofuran, then, GC analysis was conducted to find a yield of the desired 2-(2,6-dimethylphenyl)-thiophene of 90%.

Example 5

[0355] A nitrogen atmosphere was prepared in a glass reaction vessel equipped with a cooling apparatus, then, 3.0 mmol of 4,7-dibromo-5,6-difluoro-2,1,3-benzothiadiazole, 3.0 mmol of 2,2-(5,5-bis(3,7-dimethyloctyl)-5H-dithieno[3,2-b:2,3-d]pyran-2,7-diyl)bis(5-methyl-1,3,2-dioxaborinane-5-methanol), 9 mol of chloromethyl(tri-tert-butylphosphine)palladium(II), 90 mL of water, 70 mL of tetrahydrofuran and 30 mL of mesitylene were added thereto. The resultant mixture was heated at 45 C. while stirring. To the resultant mixture was added 10 mL of a 3M potassium phosphate aqueous solution. The resultant mixture was heated at 45 C. while stirring and reacted for 4 hours, to obtain a reaction mixture containing an aromatic compound comprising a repeating structural unit represented by the following formula. The resultant aromatic reaction mixture was dissolved in 1-chloronaphthalene, then, the molecular weight was analyzed by GPC, to find a molecular weight (Mw) of 3.610.sup.4.

##STR00035##

Comparative Example 3

[0356] The same procedure as in Example 5 was carried out, except that [2-(amino-N)(1,1-biphenyl)-2-yl-KC]chloro[tri-(tert-butyl)phosphine]palladium(II) was used instead of chloromethyl(tri-tert-butylphosphine)palladium(II) in Example 5. The molecular weight (Mw) of the resultant aromatic compound was 2.610.sup.4.

Example 6

[0357] Into a glass reaction vessel equipped with a cooling apparatus were added 0.0025 mmol of chloromethyl(tri-tert-butylphosphine)palladium(II), 0.5 mmol of bromobenzene, 0.5 mmol of m-tolylboronic acid, 1.0 mmol of potassium phosphate, 4.5 mL of methanol, 0.5 mL of water, and 0.07 mmol of n-nonylbenzene as an internal standard. The resultant mixture was stirred at 60 C. for 3 hours. Two hundred microliters of the resultant reaction mixture was diluted with 5 mL of tetrahydrofuran, and GC analysis was conducted to find a yield of the desired 3-methylbiphenyl of 100%.

Example 7

[0358] Into a glass reaction vessel equipped with a cooling apparatus were added 0.0025 mmol of chloromethyl(di(tert-butyl) (3,5-di(tert-butyl)phenylphosphine)palladium(II)palladium(II), 0.5 mmol of 2-bromo-m-xylene, 0.5 mmol of 2-thiopheneboronic acid, 1.0 mmol of potassium phosphate, 4.5 mL of methanol, 0.5 mL of water, and 0.07 mmol of n-octylbenzene as an internal standard. The resultant mixture was stirred at 25 C. for 3 hours. Two hundred microliters of the resultant reaction mixture was diluted with 5 mL of tetrahydrofuran, then, GC analysis was conducted to find a yield of the desired 2-(2,6-dimethylphenyl)-thiophene of 95%.

Example 8

[0359] A nitrogen atmosphere was prepared in a glass reaction vessel equipped with a dropping funnel, then, 0.18 g of 2-bromoanisole and 4 mL of tetrahydrofuran were added thereto. The resultant solution was cooled down to 70 C., then, 0.6 mL of n-butyllithium (1.63M/hexane solution) was added dropwise. The resultant mixture was stirred at 70 C. for 1 hour, then, a solution prepared by dissolving 0.20 g of chlorodicyclopentylphosphine in 4 mL of tetrahydrofuran was added dropwise. The resultant mixture was stirred at room temperature for 3 hours, then, 5 mL of a NH.sub.4Cl aqueous solution (2M) was added, and extracted with 20 mL of hexane twice. The organic layers obtained in respective extractions were mixed, and the mixture was concentrated, to obtain a mixture containing viscous liquid dicyclopentyl(2-methoxyphenyl)phosphine.

[0360] A nitrogen atmosphere was prepared in a glass reaction vessel, then, the mixture containing dicyclopentyl(2-methoxyphenyl)phosphine obtained above, 0.20 g of chloromethyl(1,5-cyclooctadiene)palladium(II) and 0.5 mL of tetrahydrofuran were added thereto. The resultant mixture was stirred at room temperature for 5 minutes, then, the resultant reaction solution was added dropwise into 9 mL of hexane. The generated solid was isolated by filtration, and washed three times with 3 mL of hexane. The resultant solid was dried under reduced pressure, to obtain 0.24 g of chloromethyl(dicyclopentyl(2-methoxyphenyl)phosphine)palladium(II) as a gray solid.

##STR00036##

chloromethyl(dicyclopentyl(2-methoxyphenyl)phosphine)palladium(II)

[0361] 1H-NMR ( ppm, CDCl.sub.3 solvent, TMS standard, 50 C.): 7.6 (t, 1H), 7.4 (t, 1H), 7.04 (t, 1H), 6.98 (s, 1H), 4.1 (s, 3H), 2.6 (d, 2H), 2.1 (m, 2H), 1.9 (s, 2H), 1.8-1.5 (m, 12H), 0.9 (s, 3H)

[0362] .sup.31P-NMR ( ppm, CDCl.sub.3 solvent): 46.8, 35.3

Example 9

[0363] A nitrogen atmosphere was prepared in a glass reaction vessel equipped with a dropping funnel, and then, 0.52 g of 2-bromoanisole and 50 mL of tetrahydrofuran were added thereto. The resultant solution was cooled down to 70 C., and then, 1.7 mL of n-butyllithium (1.63M/hexane solution) was added dropwise. The resultant mixture was stirred at 70 C. for 1 hour, and then, a solution prepared by dissolving 0.50 g of ditert-butylchlorophosphine in 17 mL of tetrahydrofuran was added dropwise. The resultant mixture was stirred at room temperature for 3 hours, and then, the resultant reaction mixture was concentrated, to obtain a mixture containing di(tert-butyl)(2-methoxyphenyl)phosphine.

[0364] A nitrogen atmosphere was prepared in a glass vessel, and then, the mixture containing di(tert-butyl)(2-methoxyphenyl)phosphine obtained above and 20 mL of diethyl ether were added and mixed. The resultant mixture was filtrated through Celite, to obtain a liquid. Into another glass reaction vessel was added the liquid obtained above. A nitrogen atmosphere was prepared in the vessel, and then, 0.49 g of tetrafluoroboric acid diethyl ether complex was added thereto, and the resultant mixture was stirred vigorously for 30 minutes. The deposited solid was isolated by filtration, then, washed three times with 10 mL of diethyl ether. The resultant solid was dried under reduced pressured at room temperature for 3 hours, to obtain di(tert-butyl)(2-methoxyphenyl)phosphonium tetrafluoroborate as a white solid.

[0365] A nitrogen atmosphere was prepared in a glass reaction vessel, and then, 0.8 g of di(tert-butyl)(2-methoxyphenyl)phosphonium tetrafluoroborate obtained above, 2 mL of diethyl ether and 0.7 mL of triethylamine were added thereto and these were stirred at room temperature for 5 minutes. A solid was isolated from the resultant suspended liquid by filtration, and the resultant liquid was added into a glass reaction vessel containing 0.35 g of chloromethyl(1,5-cyclooctadiene)palladium(II). The resultant mixture was stirred at room temperature for 30 minutes, and then, the resultant reaction solution was added dropwise into 17 mL of hexane. The generated solid was isolated by filtration, then, washed three times with 3 mL of hexane. The resultant solid was dried under reduced pressure, to obtain 0.27 g of chloromethyl(di(tert-butyl) ((2-methoxyphenyl)phosphine)palladium(II) as a white solid.

##STR00037##

chloromethyl(di(tert-butyl)((2-methoxyphenyl)phosphine)palladium(II)

[0366] 1H-NMR (5 ppm, CDCl.sub.3 solvent, TMS standard): 7.8 (t, 1H), 7.5 (t, 1H), 7.2 (t, 1H), 7.1 (m, 1H), 4.4 (s, 3H), 1.4 (d, 18H), 1.4 (d, 3H)

[0367] .sup.31P-NMR ( ppm, CDCl.sub.3 solvent): 59.8

Example 10

[0368] Into a glass reaction vessel equipped with a cooling apparatus were added 0.0025 mmol of chloromethyl(dicyclopentyl(2-methoxyphenyl)phosphine)palladium(II) obtained in Example 8, 0.5 mmol of 2-bromo-m-xylene, 0.5 mmol of 2-thiopheneboronic acid, 1.0 mmol of potassium phosphate, 4.5 mL of tetrahydrofuran, 0.5 mL of water, and 0.07 mmol of n-octylbenzene as an internal standard. The resultant mixture was stirred at 65 C. for 3 hours. Two hundred microliters of the resultant reaction mixture was diluted with 5 mL of tetrahydrofuran, and GC analysis was conducted to find a yield of the desired 2-(2,6-dimethylphenyl)-thiophene of 92%.

Example 11

[0369] 2-(2,6-dimethylphenyl)-thiophene was obtained in the same manner as in Example 10, except that chloromethyl(di(tert-butyl) ((2-methoxyphenyl)phosphine)palladium(II) obtained in Example 9 was used instead of chloromethyl(dicyclopentyl(2-methoxyphenyl)phosphine)palladium(II) in Example 10. Its yield was 92%.

TABLE-US-00001 palladium complex base yield Example 2 chloromethyl(tri-tert- potassium 94% butylphosphine)palladium(II) phosphate Example 3 chloromethyl(tri-tert- sodium 91% butylphosphine)palladium(II) carbonate Example 4 chloromethyl(di(tert-butyl)(3,5-di(tert- potassium 90% butyl)phenylphosphine)palladium(II) phosphate Example 7 chloromethyl(di(tert-butyl)(3,5-di(tert- potassium 95% butyl)phenylphosphine)palladium(II) phosphate Example 10 chloromethyl(dicyclopentyl(2- potassium 92% methoxyphenyl)phosphine)palladium(II) phosphate Example 11 chloromethyl(di(tert-butyl)((2- potassium 92% methoxyphenyl)phosphine)palladium(II) phosphate Comparative [2-(amino-N)(1,1-biphenyl)-2-yl- potassium 12% Example 1 C]chloro[tri-(tert- phosphate butyl)phosphine]palladium(II) Comparative [2-(amino-N)(1,1-biphenyl)-2-yl- sodium 75% Example 2 C]chloro[tri-(tert- carbonate butyl)phosphine]palladium(II)

TABLE-US-00002 molecular palladium complex weight (Mw) Example 5 chloromethyl(tri-tert- 3.6 10.sup.4 butylphosphine)palladium(II) Comparative [2-(amino-N)(1,1-biphenyl)- 2.6 10.sup.4 Example 3 2-yl-C]chloro[tri-(tert- butyl)phosphine]palladium(II)

INDUSTRIAL APPLICABILITY

[0370] According to the present invention, the process for producing the aromatic compound giving high yield and a catalyst used in the process can be provided.