Saltucin,Boehringer Mannheim,W. Germany,1961
Chlorsulfonic acid and 3-chloroaniline react to give an intermediate which
when treated with ammonia yields 5-chloro-2,4-disulfamylaniline.
20 g of 5-chloro-2,4-disulfamylaniline in 15 cc of diethyleneglycol-dimethyl
ether with 0.9 g of isovaleraldehyde are reacted in the presence of 0.5 cc of a
saturated solution of hydrochloric acid in ethyl acetate at 80°-90°C. The
reaction mixture is concentrated under reduced pressure, an oily product
precipitates on the addition of water, the latter is decanted and ethanol added
to the remaining oil. 3-Isobutyl-6-chloro-7-sulfamyl-3,4-dihydro-1,2,4-
benzothiadiazine-1,1-dioxide crystallizes and, after recrystallization from
dimethylformamide and water, melts at 241°-245°C.
