HCID 21433222, compound → HCID 178527179, compound

Participants

Reaction Steps

A mixture of 6 g 2-amino-4-trifluoromethyl-5-fluoro-benzenesulfonamide, m.p.= 152° C. (formula V: R2 = F) and 18 g ethyl orthoformate is heated at 120°-125° C., during 30 minutes to one hour, in an open vessel. After cooling, the reaction mixture is diluted with 150 ml dry diethyl ether. The resulting precipitate is collected and recrystallized from aqueous ethanol, to give 5.7 g of 6-trifluoromethyl-7-fluoro-2H-1,2,4-benzothiadiazine-1,1-dioxide, M.p.= 234° C. B. Action of formic acid

Provenance & Evidence