24/06/2005 - Controller General of Patents, Designs, and Trade Marks

(12) PATENT APPLICATION PUBLICATION
(19)
INDIA (21) Application No: 707/MUMNP/2003 A
(22) Date of filing of Application : 17/07/2003
(54) Title of the invention:
(51) International Classification: C 07 C 317/00 (71)
(31) Priority Document No. : 60/275,061
(32) Priority Date :
(43) Publication Date: 24/06/2005
PURIFICATION OF
2-NITRO-4-METHYLSULPHONYLBENZOIC ACID.
26/03/2001
(33) Name of priority country : U.S.A.
(86)
International Application : PCT/GB02/01433
No. and Filing Date : 25/03/2002
(87) International : WO 02/076934 A2
Publication No.
(61) Patent of addition to
Application No. : NIL
Filed on N.A.
(62)
Divisional to
Application No. : NIL
Filed on : N.A.
(72)
Name of the Applicant:
SYNGENTA LIMITED
Address of the Applicant:
EUROPEAN REGIONAL CENTRE,
PRIESTLEY ROAD,
SURREY RESEARCH PARK,
GUILDFORD, SURREY GU2 7YH,
ENGLAND.
Name of the Inventors:
1. JAVDANI KAMBIZ
2. RODRIGUEZ GILBERT
3. MUXWORTHY JAMES PETER
(57) Abstract : A method for removing impurities from 2-nitro-4-methylsulfonylbenzoic acid which comprises at least
two of the following steps, in any order, (a) dissolving 2-nitro-4-methylsulfonylbenzoic acid in water at a pH of about 2
to 10, followed by filtration; (b) contacting an aqueous solution of 2-nitro-4-methylsulfonylbenzoic acid with activated
carbon at a pH of about 2 to 10; (c) treating an aqueous solution of 2-nitro-4-methylsulfonylbenzoic acid with sufficient
base to hydrolyze undesired nitro and dinitro substituted impurities; followed by maintaining the resulting aqueous
solution comprising 2-nitro-4-methylsulfonylbenzoic acid at a temperature of up to about 95C, and adjusting the pH of
said solution to about a pH which is sufficient to effect crystallization of 2-nitro-4-methylsulfonylbenzoic acid upon
cooling.
( Figure: NIL )
Total Pages : 15.
The Patent Office Journal 24.06.2005 17819