Title:
2-ニトロ-4-メチルスルホニル安息香酸の精製
Document Type and Number:
Japanese Patent JP2004525145
Kind Code:
A
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-methylsulfonylberizoic 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 95° C., 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.
Inventors:
Cambiz, Javdani
Rodriguez, Gilbert
Max Worthy, James Peter
Rodriguez, Gilbert
Max Worthy, James Peter
Application Number:
JP2002576196A
Publication Date:
August 19, 2004
Filing Date:
March 25, 2002
Export Citation:
Assignee:
Syngenta Limited
International Classes:
C07C315/04; C07C315/06; C07C317/24; C07C317/44; C07C317/00; (IPC1-7): C07C315/06; C07C315/04; C07C317/24; C07C317/44
Attorney, Agent or Firm:
Kazuo Shamoto
Tadashi Masui
Yasushi Kobayashi
Akio Chiba
Hiroyuki Tomita
Keiko Kanemoto
Tadashi Masui
Yasushi Kobayashi
Akio Chiba
Hiroyuki Tomita
Keiko Kanemoto