Process to produce specific alpha,beta-unsaturated carboxylates

Abstract

The present invention relates to a process for producing specific ,-unsaturated carboxylates.

Claims

1. A process for producing a compound of formula (I): ##STR00026## wherein R.sub.1 is a C.sub.1-C.sub.4-alkyl moiety, and R.sub.2 is ##STR00027## wherein the symbol * shows a location where the bond is localized, wherein the process comprises: reacting a reaction mixture comprising a compound of formula (II): ##STR00028## and a compound of formula (III): ##STR00029## wherein R.sub.1 and R.sub.2 have the same meanings as defined above for the compound of formula (I), in the presence of at least one catalyst of formulas (IVa), (IVb) and/or (IVc): ##STR00030## wherein R.sub.7 is H or CH.sub.3, to form the compound of formula (I).

2. The process according to claim 1, wherein R.sub.1 is CH.sub.3 or CH.sub.2CH.sub.3.

3. The process according to claim 1, wherein R.sub.2 is ##STR00031##

4. The process according to claim 1, wherein the compound of formula (I) is a compound of formula (Ia) or (Ib): ##STR00032##

5. The process according to claim 1, wherein a mol-based ratio of the compounds of formulas (II) and (III) in the reaction mixture to the catalyst is 5000:1 to 10:1.

6. The process according to claim 1, wherein the process is carried out in the absence of solvent.

7. The process according to claim 1, wherein the process is carried out in at least one apolar aprotic organic solvent.

8. The process according to claim 7, wherein the at least one apolar aprotic organic solvent is selected from the group consisting of aliphatic hydrocarbons, cyclic hydrocarbons, aromatic hydrocarbons and carboxylate esters.

9. The process according to claim 1, wherein the process is carried out at a temperature of between 5 C. and 60 C.

10. The process according to claim 1, wherein the process comprises adding a compound of formula (V): ##STR00033## to the reaction mixture.

11. The process according to claim 10, wherein the compound of formula (V) is added to the reaction mixture in amount of 0.01-0.75 mol equivalent based on the compound of formula (II).

12. A process for producing a compound of formula (I): ##STR00034## wherein R.sub.1 is a C.sub.1-C.sub.4-alkyl moiety, and R.sub.2 is ##STR00035## and wherein the symbol * shows a location where the bond is localized, wherein the process comprises reacting a reaction mixture comprising a compound of formula (II): ##STR00036## a compound of formula (III): ##STR00037## and a compound of formula (V): ##STR00038## wherein R.sub.1 and R.sub.2 have the same meanings as defined above for the compound of formula (I), in the presence of at least one catalyst of formula (IV): ##STR00039## wherein R.sub.3, R.sub.4, R.sub.5 and R.sub.6 signify independently from each other CH.sub.3, OCH.sub.3, NO.sub.2 or halogen, W, X, Y and Z signify independently from each other a neutral or ionic ligand, wherein W, X, Y and Z can be monodentate or bidentate with the proviso that the Ru is always six times coordinated, m, n, o and p signify an integer 0, 1, 2 or 3, and q signifies an integer 1, 2, 3 or 4.

13. The process according to claim 12, wherein the compound of formula (V) is present in the reaction mixture in an amount of 0.01-0.75 mol equivalent based on the compound of formula (II).

14. The process according to claim 12, wherein R.sub.1 is CH.sub.3 or CH.sub.2CH.sub.3.

15. The process according to claim 12, wherein R.sub.2 is ##STR00040##

16. The process according to claim 12, wherein the compound of formula (I) is a compound of formula (Ia) or (Ib): ##STR00041##

17. The process according to claim 12, wherein a mol-based ratio of the compounds of formulas (II) and (III) in the reaction mixture to the catalyst is 5000:1 to 10:1.

18. The process according to claim 12, wherein the process is carried out in the absence of solvent.

19. The process according to claim 12, wherein the process is carried out in at least one apolar aprotic organic solvent.

20. The process according to claim 19, wherein the at least one apolar aprotic organic solvent is selected from the group consisting of aliphatic hydrocarbons, cyclic hydrocarbons, aromatic hydrocarbons and carboxylate esters.

21. The process according to claim 12, wherein the process is carried out at a temperature of between 5 C. and 60 C.

Description

EXAMPLES

Example 1

(1) 3-Methyl-1-(2,6,6-trimethylcyclohex-1-en-1-yl)pent-1-en-4-yn-3-ol (2.33 g, 10 mmol) and 2,2-dimethylpropanoic acid (1.53 g, 15 mmol, 1.5 eq.) were dissolved in anhydrous ethyl acetate (10 mL) under argon atmosphere. In a counter flow of argon, 61 mg (0.1 mmol, 1.0 mol %) of the [(dppe)Ru(2-methylallyl).sub.2] were added, which formed the catalyst of formula (IVa). After stirring for 24 h at 20 C., the light yellow-brown reaction mixture was concentrated under reduced pressure (rotavap, 20 C. water-bath temperature). The crude product was dried for another 2 h at 20 mbar resulting in a light brown oil. The product of formula (Ia)

(2) ##STR00025## is obtained in a yield of 99%.

(3) In the following table more compounds of formula (la) have been produced by the same way as in Example 1. Other reaction times and/or the reaction temperature and/or the amount of ethyl acetate (solvent) have been varied.

(4) TABLE-US-00001 amount of Yield carboxylic acid T t ethyl acetate carboxylate (compound of formula (III) [ C.] [h] [mL] [%] 2,2-dimethylpropanoic acid 20 24 10 >99 10 24 0 >99 20 6 0 >99 30 4 0 >99 40 2 0 95

Example 2

(5) 3-Methyl-1-(2,6,6-trimethylcyclohex-1-en-1-yl)pent-1-en-4-yn-3-ol (2.18 g, 10 mmol), 2,2-dimethylpropanoic acid (1.32 g, 11 mmol) and 2,2-dimethylpropanoic anhydride (0.4 mL, 2 mmol) were dissolved in anhydrous ethyl acetate (10 mL) under argon atmosphere. In a counter flow of argon, a solution of 61 mg (0.1 mmol, 1.0 mol %) of the [(dppe)Ru(2-methylallyl).sub.2] in anhydrous acetone (5 mL) were added, which formed the catalyst of formula (IVa). After stirring for 18 h at 20 C. a conversion of 89% 3-Methyl-1-(2,6,6-trimethylcyclohex-1-en-1-yl)pent-1-en-4-yn-3-ol was observed.

(6) In the following table more compounds of formula (Ia) have been produced by the same way as in Example 3. Other additives and/or solvent have been varied.

(7) TABLE-US-00002 Conversion of T t formula (II) Solvent [ C.] [h] Additive [%] ethyl acetate 20 18 81 ethyl acetate 20 18 2,2-dimethylpropanoic 89 anhydride (2 mmol) ethyl acetate 20 18 H.sub.2O (0.5 mol %) 49 acetone 20 18 79 acetone 20 18 2,2-dimethylpropanoic 85 anhydride (2 mmol)

Example 3

(8) 2,2-dimethylpropanoic acid (1.0 g, 9.8 mmol) and 60 mg (0.1 mmol) of the ruthenium catalyst of formula (IV) were dissolved in anhydrous ethyl acetate (15 mL) under argon atmosphere. After 0.5 h the solvent was evaporated for 2 hours (40 C.). The remaining solid was dissolved in anhydrous n-hexane at reflux and allowed to cool gradually from 60 C. to 20 C. for yellow sharp crystal formation to obtain the ruthenium catalyst of formula (IVb).

Example 4

(9) 2,2-dimethylpropanoic acid (5.0 g, 49 mmol) and 60 mg (0.1 mmol) of the ruthenium catalyst of formula (IV) were dissolved in anhydrous ethyl acetate (10 mL) under argon atmosphere. After 0.5 h the solvent was evaporated for 2 hours (40 C.). The remaining solid was dissolved in acetone and slow diffusion of n-hexane were set up for yellow sharp crystal formation to obtain the ruthenium catalyst of formula (IVc).