Tandem Reduction, Ammonolysis, Condensation, and Deamination Reaction for Synthesis of Benzothiadiazines and 1-(Phenylsulfonyl)-1 H -benzimidazoles.

A novel route for a SnCl 2 -promoted tandem reduction, ammonolysis, condensation, and deamination reaction which uses nitrile and 2-nitro- N -phenylbenzenesulfonamide/ N -(2-nitrophenyl)benzenesulfonamide to synthesize derivatives of benzothiadiazine/1-(phenylsulfonyl)-1 H -benzimidazole has been developed. The method features convenient operation and good functional group tolerance. In addition, it employs unsensitive and inexpensive SnCl 2 / i -PrOH as the reaction reagent and provides a direct approach for the synthesis of pharmaceutically important targets.