Method for preparing carboxylic acids

Patent metadata

Field	Value
Publication number	US-9018399-B1
Application number	US-201414565649-A
Country	US
Kind code	B1
Filing date	Dec 10, 2014
Priority date	Apr 9, 2014
Publication date	Apr 28, 2015
Grant date	Apr 28, 2015

Abstract

The present invention discloses a method for the preparation of carboxylic acid comprising contacting β-ketosulfone of Formula (I) with nitrous acid.

First claim

The invention claimed is:

1. Method for preparing carboxylic acid comprising contacting β-ketosulfone of Formula (I) with nitrous acid,

wherein R 1 and R 2 represent each independently unsubstituted or substituted C 1 -C 18 alkyl, which may be straight-chained or branched, unsubstituted or substituted C 6 -C 20 aryl or unsubstituted or substituted C 5 -C 20 heteroaryl, wherein
one or more substitutent(s) of the substituted C 1 -C 18 alkyl is each independently selected from halogen, unsubstituted or substituted amino, C 1 -C 4 alkyl, alkoxy, haloalkoxy or unsubstituted or substituted aryl, and
one or more substituent(s) of the substituted C 5 -C 20 aryl and C 5 -C 20 heteroaryl is each independently selected from halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, alkylthio, alkylamino, aryl, heteroaryl, aryloxy, haloaryloxy, arylthio or arylamino.

2. Method according to claim 1 , wherein the nitrous acid is formed in the presence of nitrite (R 3 —NO 2 ), with R 3 being organic or inorganic.

3. Method according to claim 2 , wherein the inorganic nitrite is a metallic nitrite, and the organic nitrite is a nitrite in which R 3 is C 1 -C 8 alkyl.

4. Method according to claim 1 , wherein the method is carried out under aqueous and/or acidic conditions.

5. Method according to claim 1 , wherein an acid is added to the reaction mixture.

6. Method according to claim 5 , wherein the acid is a mineral acid selected from the group consisting of phosphoric acid, nitric acid, sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid and perchloric acid, or the acid is an organic acid selected from acetic mono basic acids.

7. Method according to claim 1 , wherein a solvent is added, preferably water.

8. Method according to claim 7 , wherein a co-solvent is added.

9. Method according to claim 1 , wherein the reaction is stirred for 1 to 120 hours.

10. Method according to claim 1 , wherein the reaction temperature is in the range from 0 to 70° C.

11. Method according to claim 1 , wherein, subsequent to the reaction water and/or solvent is removed.

12. Method according to claim 1 , wherein the method is for the preparation of aromatic carboxylic acids.

13. Method according to claim 7 , wherein the solvent is water.

14. Method according to claim 8 , wherein the solvent is water and the co-solvent is water-miscible.

Assignees

• Univ King Saud

Inventors

• Abdel-Aziz Hatem Abdel-Khader

Classifications

• C07C51/305

  with sulfur or sulfur-containing compounds · CPC title

• C07D333/40 Primary

  Thiophene-2-carboxylic acid · CPC title

• C07D307/85

  attached in position 2 · CPC title

• C07B41/08

  of carboxyl groups or salts, halides or anhydrides thereof · CPC title