Process for the production of 5-(4'-chloro-5'-sulfamoyl-2'-thenylamino)-phenyltetrazole

摘要

The present invention provides a process for the preparation of 5-(4'-chloro-5'-sulfamoyl-2'-thenylamino)-phenyltetrazole by condensing 5-(4'-chloro-5'-sulfamoyl-2'-aminophenyl)-tetrazole with thiophene-2-aldehyde in the presence of an acid catalyst and reducing the 5-[4'-chloro-5'-sulfamoyl-2'-(thenylidene-2-amino)-phenyl]tetrazole so obtained with a boranate, wherein the condensation is carried out in dimethyl sulfoxide as solvent, with azeotropic distilling off of the water formed and the reduction is carried out in the same medium, without isolation of the 5-[4'-chloro-5'-sulfamoyl-2'-(thenylidene-2-amino)-phenyl]-tetrazole.