Intramolecular sulphonamidomethylation. Part <b>II</b>. Fused heterocycles from 2‐phenylethanesulphonamides

Abstract

Abstract 1,2,4,5‐Tetrahydro‐3,2‐benzothiazepine 3,3‐dioxides 2 , with a variety of substituents on the nitrogen atom, can be easily obtained by the title reaction. The isomeric compounds 4–6 are also formed from sulphonamides bearing an N ‐aralkyl group with a chain of two or more carbon atoms. Activation of the ring closure‐position or deactivation of the aromatic ring in the substituent can direct the reaction to give compounds 2 . Cyclization results are influenced by the size of the new heterocycle ring and by the predominant formation of derivatives with the SO 2 group outside the ring.