Process for the preparation of terpinolene epoxide

Patent metadata

Field	Value
Publication number	US-10344008-B2
Application number	US-201615571627-A
Country	US
Kind code	B2
Filing date	Apr 28, 2016
Priority date	May 8, 2015
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

The present invention relates to a process for the preparation of terpinolene epoxide by epoxidation of terpinolene.

First claim

The invention claimed is:

1. A process for the preparation of terpinolene epoxide of formula (I)

comprising reacting terpinolene with an oxidizing agent comprising hydrogen peroxide in the presence of a halogenated ketone selected from halogenated di-(C 1 -C 6 )-alkyl ketones as catalyst and the reaction is carried out in a non-halogenated inert organic solvent and in the absence of a halogenated organic solvent except halogenated di-(C 1 -C 6 )-alkyl ketones.

2. The process according to claim 1 , wherein the halogenated ketone is selected from hexafluoroacetone, hexachloroacetone, perfluoromethyl isopropyl ketone, perfluoromethyl ethyl ketone and any mixture thereof.

3. The process according to claim 1 , wherein the halogenated ketone is hexachloroacetone.

4. The process according to claim 1 , wherein the non-halogenated inert organic solvent is selected from non-halogenated aliphatic hydrocarbons, non-halogenated aromatic hydrocarbons and any mixture thereof.

5. The process according to claim 1 , wherein the non-halogenated inert organic solvent is selected from non-halogenated aromatic hydrocarbons and any mixtures thereof.

6. The process according to claim 1 , wherein the epoxidation is carried out in the presence of an organic base.

7. The process according to claim 6 , wherein the base is selected from tertiary amines, pyridine, substituted pyridines, bicyclic amines and any mixture thereof.

8. The process according to claim 6 , wherein the base is pyridine or substituted pyridines.

9. The process according to claim 6 , wherein the pH of the reaction mixture is from 3 to 6.

10. The process according to claim 1 , wherein the molar ratio of the halogenated ketone to terpinolene is from 0.05:1 to 1:1.

11. The process according to claim 1 , wherein the molar ratio of hydrogen peroxide to terpinolene is from 1:1 to 2:1.

12. The process according to claim 1 , wherein the epoxidation is carried out at 5 to 40° C.

13. The process according to claim 1 , wherein the terpinolene epoxide of formula (I) is further subjected to an epoxide ring opening isomerization leading to limonene-4-ol.

14. The process according to claim 13 , wherein limonene-4-ol is further reduced to give terpinene-4-ol.

15. A process for preparing (±)-2-exo-(2-Methylbenzyloxy)-1-methyl-4-isopropyl-7-oxabicyclo[2.2.1]heptane, any of its individual enantiomers or any non-racemic mixture thereof, comprising preparing the terpinolene epoxide of formula (I) in accordance with claim 1 .

16. The process of claim 15 , further comprising subjecting terpinolene epoxide of formula (I) to an epoxide ring opening isomerization to give limonene-4-ol.

17. The process of claim 16 , further comprising hydrogenating limonene-4-ol to afford terpinene-4-ol.

18. The process of claim 17 , further comprising treating terpinene-4-ol successively or concurrently with an oxidizing agent and an acid in an inert solvent to effect epoxidation and cyclization to give (±)-2-exo-hydroxy-1-methyl-4-isopropyl-7-oxabicyclo[2.2.1]heptane.

19. The process of claim 18 , further comprising reacting (±)-2-exo-hydroxy-1-methyl-4-isopropyl-7-oxabicyclo[2.2.1]heptane with a compound of the formula WCH 2 L wherein W is 2-methylphenyl and L is a leaving group to afford (±)-2-exo-(2-Methylbenzyloxy)-1-methyl-4-isopropyl-7-oxabicyclo[2.2.1]heptane, any of its individual enantiomers or any non-racemic mixture thereof.

Assignees

• Basf Agro Bv

Inventors

• Wolf Bernd
• Rack Michael
• Benson Stefan
• Kraus Helmut
• Goetz Roland
• Narayanan Sukunath
• Rishinaradamangalam Chidambaram

Classifications

• C07D303/04

  containing only hydrogen and carbon atoms in addition to the ring oxygen atoms · CPC title

• C07D301/36

  Use of additives, e.g. for stabilisation · CPC title

• C07D301/12 Primary

  with hydrogen peroxide or inorganic peroxides or peracids · CPC title

• C07C35/18

  with unsaturation at least in the ring · CPC title

• C07C29/56

  by isomerisation · CPC title