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

Abstract

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)-1H-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.

Nitroarenes and nitroalkenes as potential amino sources for the synthesis of N-heterocycles

“…In 2022, Xia et al interestingly utilized 2-nitro- N -phenylbenzenesulfonamides with nitriles for the synthesis of benzothiadiazine derivatives via Lewis acid-promoted tandem reduction, ammonolysis, condensation, and deamination processes (Scheme 45). 74 The reaction employs insensitive and inexpensive SnCl 2 /i-PrOH as the reaction reagent and tolerates a wide range of functional groups.…”

Debenzylation or Demethylation in Methyl Ester of O‐Alkyl Nitrophenols with Stannous Chloride Dihydrate

“…Although the reduction of nitro to an amino group is well explored with many reagents and conditions, stannous chloride dihydrate is still a widely utilized reagent as seen in many reported procedures. [1][2][3][4] Bellamy and co-workers in 1984 reported the reduction of nitro group with the reagent in a non-aqueous medium (ethanol or ethyl acetate) at 70 °C. [5] The authors reported that the substrate with an acid labile group such as the O-benzyl group in 4-benzyloxy nitrobenzene remained unaffected during the reaction condition.…”

“…Nitro is an important functional group in chemical synthesis and is a masked form of an amino group in synthetic transformation. Although the reduction of nitro to an amino group is well explored with many reagents and conditions, stannous chloride dihydrate is still a widely utilized reagent as seen in many reported procedures [1–4] . Bellamy and co‐workers in 1984 reported the reduction of nitro group with the reagent in a non‐aqueous medium (ethanol or ethyl acetate) at 70 °C [5] .…”