Intramolecular sulphonamidomethylation. Part II. Fused heterocycles from 2‐phenylethanesulphonamides

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