Synthesis of a novel series of 6‐chloro‐1,4,2‐benzodithiazine 1,1‐dioxide derivatives with potential biological activity

A novel series of 6‐chloro‐1,4,2‐benzodithiazine 1,1‐dioxide derivatives 2‐19 with alkyl, aryl or het‐eroaryl substituents at position 3 have been synthesized by the reaction of 4‐chloro‐2‐mercaptobenzenesul‐fonamides with aldehydes, aldehyde acetals or acid anhydrides. 6‐Chloro‐3‐(2‐hydroxyphenyl)‐7‐methyl‐2,3‐dihydro‐l,4,2‐benzodithiazine 1,1‐dioxide (7) exhibited remarkable activity on the leukemia CCRF‐CEM cell line (GI₅₀<10 nM) and moderate activity against the other 49 human tumor cell lines derived from nine different cancer type.