Process for preparing terpinene-4-ol

Patent metadata

Field	Value
Publication number	US-10266469-B2
Application number	US-201716079155-A
Country	US
Kind code	B2
Filing date	Feb 16, 2017
Priority date	Feb 26, 2016
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

The present invention relates to a process for preparing terpinene-4-ol from limonene-4-ol via a hydrogenation reaction in the presence of a nickel catalyst.

First claim

The invention claimed is:

1. A process for preparing terpinene-4-ol of formula (II)

said process comprising contacting limonene-4-ol of formula (I)

with hydrogen in the presence of at least one nickel catalyst and at least one inert organic solvent selected from carboxylic acid esters.

2. The process of claim 1 , wherein the nickel catalyst comprises Raney nickel.

3. The process of claim 1 , wherein the carboxylic acid ester is selected from esters of the general formula R 1 COOR 2 wherein R 1 is hydrogen or selected from the group consisting of C 1 -C 4 -alkyl, C 3 -C 6 -cycloalkyl, C 6 -C 10 -aryl and C 6 -C 10 -aryl-C 1 -C 4 -alkyl and R 2 is selected from the group consisting of C 1 -C 4 -alkyl, C 3 -C 6 -cycloalkyl, C 6 -C 10 -aryl and C 6 -C 10 -aryl-C 1 -C 4 -alkyl, each of the aforementioned groups optionally being substituted with one or more substituents selected from C 1 -C 4 -alkoxy.

4. The process of claim 1 , wherein the carboxylic acid ester is selected from C 1 -C 4 -alkyl acetates.

5. The process of claim 1 , wherein the carboxylic acid ester is ethyl acetate.

6. The process of claim 1 , wherein the temperature is from 35 to 70° C.

7. The process of claim 1 , wherein the hydrogen overpressure is from 10 mbar to 3 bar.

8. The process of claim 1 , wherein limonene-4-ol of formula (I) is prepared by isomerization of terpinolene epoxide of the formula (III)

9. The process of claim 8 , wherein terpinolene epoxide of the formula (III) is further subjected to hydrogenation.

10. The process of claim 8 , wherein the isomerization and/or hydrogenation are carried out in the presence of at least one copper catalyst.

11. The process claim 8 , wherein the isomerization and/or hydrogenation are carried out in the presence of at least one inert organic solvent selected from carboxylic acid esters.

12. The process of claim 11 , wherein a mixture comprising limonene-4-ol of the formula (I), terpinene-4-ol of the formula (II) and the at least one inert organic solvent selected from carboxylic acid esters is obtained.

13. The process of claim 1 , wherein terpinene-4-ol of the formula (II) is further converted into (±)-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
• Goetz Roland
• Kraus Helmut

Classifications

• C07C35/00

  Compounds having at least one hydroxy or O-metal group bound to a carbon atom of a ring other than a six-membered aromatic ring · CPC title

• C07C29/56

  by isomerisation · CPC title

• C07C2601/16

  the ring being unsaturated · CPC title

• C07C29/17 Primary

  by hydrogenation of carbon-to-carbon double or triple bonds · CPC title

• C07C35/18

  with unsaturation at least in the ring · CPC title