Dehydrogenation reaction

Patent metadata

Field	Value
Publication number	US-10899694-B2
Application number	US-201716307665-A
Country	US
Kind code	B2
Filing date	Jun 26, 2017
Priority date	Jun 27, 2016
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

The present invention relates to the field of organic synthesis and more specifically it concerns a process for the dehydrogenation of compound of formula (I) catalyzed by palladium (Pd0) in elemental metallic form.

First claim

The invention claimed is:

1. A process for the preparation of a compound of formula (I)

in a form of any one of its stereoisomers or a mixture thereof and wherein R 1 , R 2 and R 3 , simultaneously or independently, represent a linear or branched C 1-6 alkyl or alkenyl group or a linear C 2-5 alkynyl group, optionally comprising one or two functional groups selected amongst ether and ester; and R 4 represents a hydrogen atom, a linear or branched C 1-6 alkyl or alkenyl group or a linear C 2-5 alkynyl group, optionally comprising one or two functional groups selected amongst ether, and ester; R 1 and R 3 , taken together, represent a C 2-9 alkanediyl or alkenediyl group optionally substituted by one to two linear or branched C 1-5 alkyl or C 2-5 alkenyl groups; or/and R 2 and R 4 , taken together, represent a C 2-9 alkanediyl or alkenediyl group optionally substituted by one to five linear or branched C 1-5 alkyl or C 2-5 alkenyl groups; or/and R 3 and R 4 , taken together, represent a C 2-9 alkanediyl or alkenediyl group optionally substituted by one to two linear or branched C 1-5 alkyl or C 2-5 alkenyl groups;
comprising the step of dehydrogenate compound of the formula (II)

in a form of any one of its stereoisomers and wherein R 1 , R 2 , R 3 , and R 4 have the same meaning as in formula (I);
said dehydrogenation being performed under an inert atmosphere in the presence of Palladium) (Pd 0 ) catalyst in elemental metallic form, wherein the reaction is carried out in the liquid phase.

2. The process according to claim 1 , characterized in that the compound of formula (I) is compound of formula (III)

in a form of any one of its stereoisomers; wherein n is 0 or 1; R 5 groups represent, when taken separately, independently of each other, a hydrogen atom, a C 1-3 alkyl or alkenyl group; or two R 5 groups represent, when taken together, a C 1-5 alkanediyl or alkenediyl group optionally substituted by one to five linear C 1-3 alkyl groups; R 6 represents a linear or branched C 1-6 alkyl or alkenyl group or a linear C 2-5 alkynyl group, optionally comprising one or two functional groups selected amongst ether, and ester; R 7 , represents a hydrogen atom, a linear or branched C 1-6 alkyl or alkenyl group or a linear C 2-5 alkynyl group, optionally comprising one or two functional groups selected amongst ether, and ester; R 6 and R 7 , taken together, represent a C 2-9 alkanediyl or alkenediyl group optionally substituted by one to five linear or branched C 1-5 alkyl groups.

3. The process according to claim 1 , characterized in that the compound of formula (II) is compound of formula (IV)

in a form of any one of its stereoisomers; wherein n is 0 or 1; R 5 groups represent, when taken separately, independently of each other, a hydrogen atom, a C 1-3 alkyl or alkenyl group; or two R 5 groups represent, when taken together, a C 1-5 alkanediyl or alkenediyl group optionally substituted by one to five liner C 1-3 alkyl groups; R 6 represents a linear or branched C 1-6 alkyl or alkenyl group or a linear C 2-5 alkynyl group, optionally comprising one or two functional groups selected amongst ether, and ester; R 6 and R 7′ taken together, represent a C 2-9 alkanediyl or alkenediyl group optionally substituted by one to five linear or branched C 1-5 alkyl groups.

4. The process according to claim 1 , characterized in that the compound of formula (I) is compound of formula (V)

in a form of any one of its stereoisomers; wherein n is 0 or 1; R 5 represents a hydrogen atom, a C 1-3 alkyl or alkenyl group; R 6 represents a linear or branched C 1-6 alkyl or alkenyl group or a linear C 2-5 alkynyl group, optionally comprising one or two functional groups selected amongst ether, and ester; R 7 , represents a hydrogen atom, a linear or branched C 1-6 alkyl or alkenyl group or a linear C 2-5 alkynyl group, optionally comprising one or two functional groups selected amongst ether, and ester; R 6 and R 7 , taken together, represent a C 2-9 alkanediyl or alkenediyl group optionally substituted by one to five linear or branched C 1-5 alkyl groups.

5. The process according to claim 1 , characterized in that the compound of formula (II) is compound of formula (IV)

in a form of any one of its stereoisomers; wherein n wherein n is 0 or 1; R 5 groups represent, when taken separately, independently of each other, a hydrogen atom, a C 1-3 alkyl or alkenyl group; or two R 5 groups represent, when taken together, a C 1-5 alkanediyl or alkenediyl group optionally substituted by one to five linear C 1-3 alkyl groups; R 6 represents a linear or branched C 1-6 alkyl or alkenyl group or a linear C 2-5 alkynyl group, optionally comprising one or two functional groups selected amongst ether, and ester; R 7 , represents a hydrogen atom, a linear or branched C 1-6 alkyl or alkenyl group or a linear C 2-5 alkynyl group, optionally comprising one or two functional groups selected amongst ether, and ester; R 6 and R 7 , taken together, represent a C 2-9 alkanediyl or alkenediyl group optionally substituted by one to five linear or branched C 1-5 alkyl groups.

6. The process according to claim 2 , characterized in that n is 0.

7. The process according to claim 2 , characterized in that R 5 represents a hydrogen atom, a methyl, an ethyl, a propyl an isopropyl or propen-2-yl group.

8. The process according to claim 2 , characterized in that R 5 represents a hydrogen atom, a methyl an ethyl or propen-2-yl group.

9. The process according to claim 2 , characterized in that R 6 represents a methyl, an ethyl, a propyl an isopropyl, a butyl, a pentyl, a pentenyl, a hexenyl, a 1-methoxy-1-oxoheptan-3-yl or 3-methylbut-2-en-1-yl group.

10. The process according to claim 2 , characterized in that R 6 represents a methyl or pentyl group.

11. The process according to claim 2 , characterized in that R 7 represents a hydrogen atom, a methyl, an ethyl or a propyl group or a C 1-3 alkyl acetate group.

12. The process according to claim 2 , characterized in that R 7 represents a hydrogen atom, a methyl group or C 1-3 alkyl acetate group.

13. The process according to claim 3 , characterized in that the compound of formula (IV) may be methyl 2-(3-oxo-2-pentylcyclopentyl)acetate, 3-methyl-2-pentylcyclopentan-1-one, 2-pentylcyclopentan-1-one, methyl 3-(2-oxocyclopentyl)heptanoate, 2,2,6-trimethylcyclohexan-1-one, 6-ethyl-2,2-dimethylcyclohexan-1-one, 2-ethyl-4,4-dimethylcyclohexan-1-one or 2,3,8a-trimethyloctahydronaphthalen-1(2H)-one.

14. The process according to claim 1 , characterized in that the palladium) (Pd 0 ) is supported on a carrying material.

15. The process according to claim 1 , characterized in that palladium is supported on aluminum oxide or charcoal.

16. The process according to claim 2 , characterized in that R 6 represents a pentyl group.

Assignees

• Firmenich & Cie

Inventors

• Jacoby Denis
• Riedhauser Jean-Jacques
• Miranda Philippe
• Randall Harvey
• Keller Fabrice

Classifications

• C07C2602/28

  Hydrogenated naphthalenes · CPC title

• C07C2601/16

  the ring being unsaturated · CPC title

• C07C2601/10

  the ring being unsaturated · CPC title

• C07C69/738

  Esters of keto-carboxylic acids {or aldehydo-carboxylic acids} · CPC title

• C07C67/317

  by splitting-off hydrogen or functional groups; by hydrogenolysis of functional groups · CPC title