Process for preparing the dialdehyde of vinylcyclohexene

Abstract

Process for preparing the dialdehyde of vinylcyclohexene

Claims

1. Process comprising the process steps of: a) initially charging vinylcyclohexene; b) adding a compound of formula (I): ##STR00007## where R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 are selected from: H, (C.sub.1-C.sub.12)-alkyl, -Ph; c) adding a Pt compound capable of forming a complex; d) adding an iodine compound; e) feeding in CO and H.sub.2; f) heating the reaction mixture from steps a) to e), to convert the vinylcyclohexene to the dialdehyde.

2. Process according to claim 1, where R.sup.1 and R.sup.4 are H.

3. Process according to claim 1, where R.sup.5, R.sup.6, R.sup.7, R.sup.8 are -Ph.

4. Process according to claim 1, where R.sup.2 and R.sup.3 are (C.sub.1-C.sub.12)-alkyl.

5. Process according to claim 1, where R.sup.2 and R.sup.3 are CH.sub.3.

6. Process according to claim 1, wherein the compound (I) has the structure (1): ##STR00008##

7. Process according to claim 1, wherein the Pt compound is selected from: Pt(II)I.sub.2, Pt(IV)I.sub.4, diphenyl(1,5-COD)Pt(II), Pt(II)(acac).sub.2, Pt(0)(PPh.sub.3).sub.4, Pt(0)(DVTS) solution (CAS: 68478-92-2), Pt(0)(ethylene)(PPh.sub.3).sub.2, tris(benzylideneacetone)Pt(0), Pt(II)(OAC).sub.2 solution, Pt(0)(t-Bu).sub.2, Pt(II)(COD)Me.sub.2, Pt(II)(COD)I.sub.2, Pt(IV)IMe.sub.3, Pt(II)(hexafluoroacetylacetonate).sub.2.

8. Process according to claim 1, wherein PtI.sub.2 is added in an amount, measured in mol % based on vinylcyclohexene, so that the value is in the range of 0.1 mol % to 5 mol %.

9. Process according to claim 1, comprising the additional process step e): e) adding a solvent.

10. Process according to claim 1, wherein the process comprises the additional process step g): g) converting the dialdehyde to the diol.

11. Process according to claim 10, wherein the conversion of the dialdehyde to the diol is carried out using Shvo's catalyst (CAS 104439-77-2).

12. Aldehyde mixture comprising the compounds (2a) and (2b): ##STR00009##

13. Alcohol mixture comprising the compounds (3a) and (3b): ##STR00010##

Description

EXPERIMENTAL DESCRIPTION

Conversion of Vinylcyclohexene to the Dialdehyde

[0044] ##STR00005##

mmol of 4-vinylcyclohex-1-ene, 10 ml of absolute toluene, 0.5 mol % PtI.sub.2, 2.2 equivalents of xantphos (1) (based on Pt) are placed under argon in a 25 ml steel autoclave from Parr Instruments. The autoclave is pressurized to 40 bar with synthesis gas (CO/H.sub.2=1:1) and the reaction started by heating to 120 C. and stirring. This reaction is conducted at 40 bar/120 C. for 3.5 h. The autoclave is then cooled, the pressure released and a GC sample taken.

[0045] In a comparative experiment, Rh(acac)(CO).sub.2 was added instead of PtI.sub.2. The reaction with Rh(acac)(CO).sub.2 ran over 11 h.

[0046] Yield of dialdehyde (2a)+(2b):

[0047] PtI.sub.2: 92%

[0048] Rh(acac)(CO).sub.2: <14%

Conversion of the Dialdehyde to the Diol.

[0049] ##STR00006##

[0050] 30 mmol of the isomeric mixture of the dialdehyde, 25 ml of absolute toluene, 176 mg of Shvo's catalyst (CAS 104439-77-2) are transferred under argon to a 100 ml Parr pressure autoclave. The autoclave is pressurized to 50 bar with hydrogen and the reaction carried out with stirring at 100 C. for 1 h and at 110 C. for a further 30 minutes. The reaction is then discontinued (autoclave cooled and the pressure released). The reaction solution is transferred to a Schlenk vessel. Two phases are formed, the lower phase is isolated and freed of toluene in vacuo. This gives the isomeric mixture of the diol (3a)+(3b).

[0051] Yield of diol (3a)+(3b): 85%

[0052] As the experimental results show, the object is achieved by the process according to the invention.