	US 11,932,613 B2
	Process for preparing 1,1,3-trioxo-1,2-benzothiazole-6-carboxamide
Bijukumar Gopinathan Pillai, Gujarat (IN); Sima Mirilashvili, Lod (IL); Yaniv Barda, Rehovot (IL); Bhavinkumar P. Hamirani, Gujarat (IN); Bhoopal Meka, Telengana (IN); and Sreedevi Mannam, Telengana (IN)
Assigned to ADAMA AGAN LTD., Ashdod (IL)
Filed by Bijukumar Gopinathan Pillai, Gujarat (IN); Sima Mirilashvili, Lod (IL); Yaniv Barda, Rehovot (IL); Bhavinkumar P. Hamirani, Gujarat (IN); Bhoopal Meka, Telengana (IN); and Sreedevi Mannam, Telengana (IN)
Filed on Aug. 17, 2020, as Appl. No. 16/994,855.
Application 16/994,855 is a division of application No. 16/066,965, granted, now 10,774,055, previously published as PCT/IB2016/001927, filed on Dec. 28, 2016.
Prior Publication US 2021/0347746 A1, Nov. 11, 2021
Int. Cl. C07D 239/52 (2006.01); C07D 239/69 (2006.01); C07D 275/06 (2006.01)

CPC C07D 275/06 (2013.01) [C07D 239/52 (2013.01); C07D 239/69 (2013.01)]

17 Claims

1. In a process of making mesosulfuron-methyl which comprises preparing a 1,1,3-trioxo-1,2-benzothiazole-6-carboxamide of formula (I) or a salt thereof

and providing reaction conditions for preparation of mesosulfuron-methyl as follows:

the improvement comprising preparing the 1,1,3-trioxo-1,2-benzothiazole-6-carboxamide of formula (I) or a salt thereof by:

(a) oxidizing 2,5-dimethyl-benzenesulfonamide of formula (II) or a salt thereof;

in the presence of an oxidizing agent to obtain 2-sulfamoyl-terephthalic acid of formula (III) or a salt thereof;

(b) converting the formed 2-sulfamoyl-terephthalic acid of formula (III) to obtain 2-sulfamoyl-terephthalic acid derivative of formula (IV) or a salt thereof;

and

(c) reacting the resulting 2-sulfamoyl-terephthalic acid derivative of formula (IV) with ammonia (NH₃) or ammonium containing-salt;

wherein R represents OR′ or Cl and R′ represents a branched or non-branched C₁-C₁₂alkyl.