A convenient synthesis of nitro‐substituted 1,2‐benzisothiazol‐3(2H)‐one 1,1‐dioxides (nitrosaccharins)

Abstract

Nitro‐substituted 1,2‐benzisothiazol‐3(2H)‐one 1,1‐dioxides (nitrosaccharins) have been synthesized by amminolysis of nitro 2‐chlorosulfonylbenzoate esters. This method appears to have advantages over the original procedure of oxidation of an ortho‐toluenesulfonamide.

Advances in the Chemistry of Saccharins: From Synthetic Novelties Towards Biologically Active Compounds

“…Whereas Nsubstituted derivatives undergo facile ring opening with various bases (nucleophiles), this was not observed in the case of their unsubstituted counterparts, since these acidic imides are stabilized as the anion [8]. N-substituted saccharins are thermodynamically more stable than their isomeric O-substituted derivatives (pseudosaccharins) on account of their amide character, as opposed to the imidate moiety of the pseudosaccharins.…”

1,2-Benzisothiazole Derivatives Bearing 4-, 5-, or 6-Alkyl/arylcarboxamide Moieties Inhibit Carbonic Anhydrase Isoform IX (CAIX) and Cell Proliferation under Hypoxic Conditions

“…The target inhibitors 4a , b , h , 5b – f , h , j , and 6a – g were synthesized as illustrated in Scheme . The starting 4-, 5-, and 6-aminobenzo­[ d ]­isothiazol-3­(2 H )-one 1,1-dioxide derivatives 1 – 3 were prepared according to synthetic methods previously described by Rose and Saary et al Once obtained, the key intermediates 1 – 3 afforded the aroyl-substituted compounds by treatment with the suitable aryl chloride, in anhydrous toluene and in the presence of triethylamine. Derivative 5j , bearing an acetylamino substituent on the distal phenyl ring, was synthesized by reaction of the amino compound 2 with acetic anhydride, at 100 °C.…”

“…Acetic anhydride and the suitably substituted aroyl chlorides, used to obtain the target inhibitors, were from Alfa Aesar, Aldrich, and Fluka. The 4-, 5-, and 6-aminosaccharin, exploited to prepare the target inhibitors were obtained as reported previously. , …”