Process for the manufacture of alkenones

Patent metadata

Field	Value
Publication number	US-9365480-B2
Application number	US-201314422043-A
Country	US
Kind code	B2
Filing date	Aug 20, 2013
Priority date	Aug 22, 2012
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

A process for the manufacture of an alkenone comprising the steps of: (a) providing a halogenated precursor of the alkenone and (b) subjecting at least a fraction of the halogenated precursor of step (a) to a thermolysis reaction to form a reaction mixture comprising the alkenone and a hydrogen halide wherein the hydrogen halide is removed from the reaction mixture by cyclonic separation is described.

First claim

The invention claimed is:

1. A process for the manufacture of an alkenone comprising the following steps:
(a) providing a halogenated precursor of the alkenone and
(b) subjecting at least a fraction of the halogenated precursor of step (a) to a thermolysis reaction to form a reaction mixture comprising the alkenone and a hydrogen halide wherein the hydrogen halide is removed from the reaction mixture by cyclonic separation.

2. The process of claim 1 further comprising the steps of
(c) transferring at least a fraction of the reaction mixture from step (b) into a separate reactor, and
(d) subjecting the transferred reaction mixture comprising unreacted halogenated precursor to a thermolysis reaction to form further alkenone and hydrogen halide.

3. The process of claim 2 wherein a fraction of equal to or more than 10% of the hydrogen halide is eliminated from the halogenated precursor of step (a) in step (b).

4. The process of claim 1 wherein the thermolysis reaction in step (b) is a flash thermolysis reaction.

5. The process of claim 2 wherein step (b) is carried out at a temperature equal to or more than 10° C. lower than the temperature of step (d).

6. The process of claim 1 wherein step (a) is performed in a first reactor and step (b) is performed in a second reactor.

7. The process of claim 6 wherein the reactor in step (b) is a tubular reactor comprising a heating segment.

8. The process of claim 1 wherein the process is performed continuously.

9. The process of claim 1 , wherein the halogenated precursor of the alkenone corresponds to Formula (I): R 1 —C(O)—CH 2 —CH(X)—OR 2 (I) wherein X represents fluorine, chlorine or bromine and R 1 represents an alkyl group which is optionally substituted by at least one halogen atom or R 1 represents CF 3 C(O)CH 2 ; and R 2 represents aryl, substituted aryl, or an alkyl group which is optionally substituted by at least one halogen atom.

10. The process of claim 9 , wherein R 1 is a fluorinated C1-C4 alkyl group.

11. The process of claim 9 , wherein R 2 is a C1-C4 alkyl group.

12. The process of claim 1 wherein the alkenone is 4 ethoxy-1,1,1-trifluoro-3-buten-2-one.

13. The process of claim 1 wherein the hydrogen halide is hydrogen chloride.

14. The process according to claim 1 comprising at least one further step (e) comprising conversion of the alkenone to a heterocyclic compound wherein the hydrogen halide formed in step (b) is used in step (e).

15. The process according to claim 14 wherein the heterocyclic compound is a CF 3 -pyridine derivative or a CF 3 -pyrazole derivative.

16. The process of claim 2 wherein the thermolysis reaction in step (b) and/or in step (d) is a flash thermolysis reaction.

17. The process of claim 10 , wherein R 1 is a CHF 2 , CClCF 2 , or a CF 3 group.

18. The process of claim 17 , wherein R 1 is a CF 3 group.

19. The process of claim 11 , wherein R 2 is a methyl or an ethyl group.

20. The process according to claim 2 comprising at least one further step (e) comprising conversion of the alkenone to a heterocyclic compound wherein the hydrogen halide formed in step (b) and/or step (d) is used in step (e).

Assignees

• Solvay

Inventors

• Braun Max Josef
• Palsherm Stefan

Classifications

• C07C45/82

  by distillation · CPC title

• C07C49/255

  containing ether groups, [IMAGE cpc-sch-C07C-0958.gif] groups,[IMAGE cpc-sch-C07C-0959.gif] groups, or[IMAGE cpc-sch-C07C-0960.gif] groups · CPC title

• C07C45/65 Primary

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

• C07C45/41 Primary

  by hydrogenolysis or reduction of carboxylic groups or functional derivatives thereof · CPC title

• C07C49/175

  containing ether groups, [IMAGE cpc-sch-C07C-0958.gif] groups,[IMAGE cpc-sch-C07C-0959.gif] groups, or[IMAGE cpc-sch-C07C-0960.gif] groups · CPC title