Heterocycles With a Benzothiadiazepine Moiety. IV. Synthesis of Novel Tetracyclic Rings by Intramolecular Cyclization of 10-Bromoacetyl-10,11-dihydro-11-ethoxycarbonyl-pyrrolo[1,2-b] [1,2,5] Benzothiadiazepine 5,5-Dioxide and Its Derivatives

Abstract

Two novel tetracyclic derivatives, namely 5 and 8, have been synthesized by intramolecular cyclization of the 10-bromoacetyl-10,11-dihydro-11-ethoxycarbonylpyrrolo[1,2-b] [1,2,5]benzothiadiazepine 5,5-dioxide (3) and, respectively, the bis-methylamide of 11-carboxy-10,11-dihydropyrrolo[1,2-b] [1,2,5]benzothiadiazepine-11-acetic acid 5,5-dioxide (4). The last compound formed when treating with an excess of methylamine either the lactam 5 or the diethyl ester of 11-carboxy-10,11-dihydropyrrolo[1,2-b] [1,2,5]benzothiadiazepine-11-acetic acid 5,5-dioxide (7). An unambiguous synthesis of the diester 7 was achieved to confirm the chemical structure of derivatives 4 and 5.