# US 9,040,742 B2 · Catalytic synthesis of vitamin A intermediate

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- Number: US 9,040,742 B2
- Document ID: US9040742B2
- Status: Granted
- Kind: B2
- Application number: 14/368,914
- Filed: 2012-12-14
- Published: 2015-01-29
- Granted: 2015-05-26
- Earliest claimed: 2011-12-27
- Assignees: Dsm IP Assets B.V.
- Applicants: Dsm IP Assets B.V.
- Inventors: Werner Bonrath; Bettina Wuestenberg; Thomas Netscher; Jan Schuetz
- Web page: https://patentgrep.com/patent/US9040742B2

## CPC

- C07C 67/29: by introduction of oxygen-containing functional groups
- C07C 403/12: by esterified hydroxy groups
- C07C 2601/16: the ring being unsaturated
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

The present invention relates to a process of production of a compound, which is useful as an intermediate (building block) in organic synthesis, especially in the synthesis of vitamin A or β-carotene and derivatives thereof, e.g. canthaxanthin, astaxanthin or zeaxanthin.

## Claims

### Claim 1

A process for the production of compounds of formula (I):
wherein
R1 signifies a C1-C15 alkyl moiety or a C2-C18 alkenyl moiety, wherein the process comprises reacting a compound of formula (II):
with a compound of formula (III):
wherein R1 has the same definition as for compound (I),
and at least one organic nitrogen containing base, in the presence of Zn[SO3CF3]2 as catalyst.

### Claim 2 (depends on 1)

The process according to claim 1, wherein R1 signifies methyl, ethyl and pentadecyl.

### Claim 3 (depends on 1)

The process according to claim 1 wherein R1 signifies an unbranched C2-C18 alkenyl moiety, which can have more than three C—C double bonds.

### Claim 4 (depends on 1)

The process according to claim 1, wherein the Zn[SO3CF3]2 catalyst is present in an amount of 5 mol-% to 20 mol-%, with regard to a molar amount of compound (II).

### Claim 5 (depends on 1)

The process according to claim 1, wherein the organic nitrogen containing base is a cyclic amine or acyclic amine.

### Claim 6 (depends on 1)

The process according to claim 1, wherein the organic nitrogen containing base is present in an amount up to 40 mol-%, with regard to a molar amount of compound (II).

### Claim 7 (depends on 1)

The process according to claim 1, wherein the reaction is carried out in a non-polar or polar aprotic solvent.

### Claim 8 (depends on 7)

The process according to claim 7, wherein the solvent is a polar aprotic solvent.

### Claim 9 (depends on 1)

The process according to claim 1, wherein the reaction is carried out at a temperature between 20 to 100° C.

### Claim 10 (depends on 5)

The process according to claim 5, wherein the organic nitrogen containing base is at least one tertiary amine.

### Claim 11 (depends on 10)

The process according to claim 10, wherein the at least one tertiary amine is selected from the group consisting of N,N-diisopropylethylamine, triethylamine and N,N-dicyclohextylmethyl-amine.