Method for preparing dialdehyde from vinylcyclohexene

Abstract

A process for preparing dialdehydes from vinylcyclohexene.

Description

Technical Field

[0001] The present invention relates to a method for preparing dialdehydes from vinylcyclohexene. Background Art

[0002] US 2009 / 0171125 A1 describes a process for the hydroformylation of cyclic olefins, using an Rh catalyst. Summary of the Invention

[0003] The object of the present invention was to provide a novel hydroformylation process which should provide increased yields compared to the processes known from the prior art.

[0004] This object is achieved by the following method.

[0005] The method comprises the following steps:

[0006] a) pre-inserting vinylcyclohexene;

[0007] b) adding a compound according to formula (I):

[0008]

[0009] where R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 Selected from: -H, -(C1-C 12 )-alkyl, -Ph;

[0010] c) adding a Pt compound capable of forming a complex;

[0011] d) adding an iodine compound;

[0012] e) supply of CO and H2;

[0013] f) heating the reaction mixture from a) to e), wherein the vinylcyclohexene is converted into the dialdehyde.

[0014] Here, process steps a) to e) can be carried out in any order. However, the addition of CO and H2 is usually carried out after the reaction partners in steps a) to d) have been previously charged.

[0015] In this case, method steps c) and d) can also be carried out in one step, for example by adding PtI 2 .

[0016] In a variant of the process, the Pt compound and the iodine compound are added in one step by adding PtI2.

[0017] Terminology (C1-C 12 )-Alkyl includes straight-chain and branched alkyl groups having 1 to 12 carbon atoms. These are preferably (C1-C8)-alkyl, particularly preferably (C1-C6)-alkyl, most preferably (C1-C4)-alkyl.

[0018] Suitable (C1-C 12 )-alkyl, in particular methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-pentyl, 2-methylbutyl, 3-methylbutyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 2-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2- Dimethylbutyl, 2,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethylbutyl, 1-ethyl-2-methylpropyl, n-heptyl, 2-heptyl, 3-heptyl, 2-ethylpentyl, 1-propylbutyl, n-octyl, 2-ethylhexyl, 2-propylheptyl, nonyl, decyl.

[0019] In one variation of this approach, R 1 and R 4 Yes -H.

[0020] In one variation of this approach, R 5 、R 6 、R 7 、R 8 Yes - Ph.

[0021] In one variation of this approach, R 2 and R 3 Yes-(C1-C 12 )-alkyl.

[0022] In one variation of this approach, R 2 and R 3 It is -CH3.

[0023] In one variation of this method, compound (I) has structure (1):

[0024]

[0025] In one variation of the method, the Pt compound is selected from the group consisting of: Pt(II)I2, Pt(IV)I4, diphenyl(1,5-COD)Pt(II), Pt(II)(acac)2, Pt(0)(PPh3)4, Pt(0)(DVTS) solution (CAS: 68478-92-2), Pt(0)(ethylene)(PPh3)2, tri(benzylideneacetone)Pt(0), Pt(II)(OAC)2 solution, Pt(0)(t-Bu)2, Pt(II)(COD)Me2, Pt(II)(COD)I2, Pt(IV)IMe3, Pt(II)(hexafluoroacetylacetonate)2.

[0026] In one variant of the method, the Pt compound is selected from the group consisting of: Pt(II)I2, Pt(II)(acac)2.

[0027] In one variation of the method, the Pt compound is Pt(II)I2.

[0028] In one variation of the method, the iodine compound is selected from the group consisting of alkali metal halides, alkaline earth metal halides, NH4X, alkylammonium halides, dialkylhalogenides, trialkylhalogenides, tetraalkylhalogenides and cycloalkylammonium halides.

[0029] In one variant of the method, the iodine compound is selected from: Pt(II)I2, LiI.

[0030] In one variant of the process, PtI 2 is added in an amount measured in mol % relative to vinylcyclohexene such that the value is in the range from 0.1 mol % to 5 mol %.

[0031] In one variant of the process, PtI 2 is added in an amount measured in mol % relative to vinylcyclohexene such that the value is in the range from 0.1 mol % to 3 mol %.

[0032] In one variant of the process, PtI2 is added in an amount measured in mol % relative to vinylcyclohexene such that the value is in the range from 0.1 mol % to 1 mol %.

[0033] In one variant of the method, the method comprises the additional method step e'):

[0034] e') Adding solvent.

[0035] In one variation of the process, the solvent is selected from the group consisting of: THF, DCM, ACN, heptane, DMF, toluene, Texanol, pentane, hexane, octane, isooctane, decane, dodecane, cyclohexane, benzene, xylene, Marlotherm, propylene carbonate, MTBE, diglyme, triglyme, ethyl ether, dioxane, isopropanol, tert-butanol, isononanol, isobutanol, isoamyl alcohol, ethyl acetate.

[0036] In one variation of the process, the solvent is selected from the group consisting of: THF, DCM, ACN, heptane, DMF, toluene, Texanol.

[0037] In one variant of the process, CO and H2 are introduced at a pressure of 1 MPa (10 bar) to 6 MPa (60 bar).

[0038] In one variant of the process, CO and H2 are introduced at a pressure of 1 MPa (20 bar) to 6 MPa (50 bar).

[0039] In one variant of the process, heating is to a temperature of 30°C to 150°C.

[0040] In one variant of the process, heating is to a temperature of 80°C to 140°C.

[0041] In a variant of the method, the method comprises the additional method step g):

[0042] g) converting the dialdehyde into a diol.

[0043] In one variant of the process, the dialdehyde is converted to the diol using "Shvos catalyst" (CAS 104439-77-2).

[0044] In addition to the process described, mixtures of aldehydes of (2a) and (2b), and mixtures of alcohols of (3a) and (3b) are also claimed.

[0045] An aldehyde mixture comprising compounds (2a) and (2b):

[0046]

[0047] An alcohol mixture comprising compounds (3a) and (3b):

[0048] DETAILED DESCRIPTION

[0049] The invention will be explained in more detail below with the aid of exemplary embodiments.

[0050] Experimental Description

[0051] Conversion of vinylcyclohexene to dialdehyde

[0052]

[0053] Under argon, 10 mmol of 4-vinyl-1-hexene, 10 ml of anhydrous toluene, 0.5 mol% PtI2, and 2.2 equivalents of 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos) (1) (based on Pt) were added to a 25 ml steel autoclave from Parr Instruments. 40 bar of synthesis gas (CO / H2=1:1) was introduced and the reaction was started by heating to 120°C and stirring. The reaction was carried out at 40 bar / 120°C for 3.5 hours. The autoclave was then cooled, the pressure was released, and a GC sample was collected.

[0054] In the comparative experiment, Rh(acac)(CO)2 was added instead of PtI2.

[0055] The reaction with Rh(acac)(CO)2 took 11 hours.

[0056] Dialdehyde (2a) + (2b) yield:

[0057] PtI2:92%

[0058] Rh(acac)(CO)2:<14%

[0059] Conversion of dialdehydes into diols

[0060]

[0061] Under argon, 30 mmol of the dialdehyde isomers, 25 ml of anhydrous toluene, and 176 mg of "Shvos catalyst" (CAS 104439-77-2) were transferred to a 100 ml Parr autoclave. 50 bar of hydrogen was introduced, and the reaction was allowed to proceed with stirring at 100° C. for 1 hour and at 110° C. for a further 30 minutes. The reaction was then stopped (the autoclave was cooled and the pressure released). The reaction solution was transferred to a Schlenk vessel. Two phases formed, the lower phase was separated, and the toluene was removed in vacuo. This gave an isomeric mixture of diols (3a) + (3b).

[0062] Diol (3a) + (3b) yield: 85%

[0063] As shown by the experimental results, this object is achieved by the method of the present invention.

Claims

1. A method for preparing dialdehyde from vinylcyclohexene, comprising the following steps: a) pre-inserting vinylcyclohexene; b) adding a compound according to formula (I): where R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 Selected from: -H, -(C1-C 12 )-alkyl, -Ph; c) adding a Pt compound capable of forming a complex; d) adding an iodine compound; e) supply of CO and H2; f) heating the reaction mixture from a) to e), wherein the vinylcyclohexene is converted into the dialdehyde.

2. The method according to claim 1, where R 1 and R 4 Yes -H.

3. The method according to claim 1 or 2, where R 5 、R 6 、R 7 、R 8 Yes - Ph.

4. The method according to claim 1, where R 2 and R 3 Yes-(C1-C 12 )-alkyl.

5. The method according to claim 1, where R 2 and R 3 It is -CH3.

6. The method according to claim 1, Wherein compound (I) has structure (1):

7. The method according to claim 1, The Pt compound is selected from: Pt(II)I2, Pt(IV)I4, diphenyl(1,5-COD)Pt(II), Pt(II)(acac)2, Pt(0)(PPh3)4, Pt(0)(DVTS) solution, which has CAS: 68478-92-2, Pt(0)(ethylene)(PPh3)2, tri(benzylideneacetone)Pt(0), Pt(II)(OAC)2 solution, Pt(0)(t-Bu)2, Pt(II)(COD)Me2, Pt(II)(COD)I2, Pt(IV)IMe3, Pt(II)(hexafluoroacetylacetonate)2.

8. The method according to claim 1, Wherein PtI2 is added in an amount measured in mol% relative to vinylcyclohexene such that the value is in the range of 0.1 mol% to 5 mol%.

9. The method according to claim 1, comprising the additional method step e'): e') Adding solvent.

10. The method according to claim 1, The method comprises the additional method step g): g) converting the dialdehyde into the diol.

11. The method according to claim 10, The "Shvos catalyst" with CAS number 104439-77-2 is used to convert dialdehydes into diols.

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