Azabenzocycloheptenones. Part XI. Synthesis and some reactions of the tetrahydrobenz[c]azepin-5-one system

Abstract

Cyclisation of N-(m-methoxybenzyl)-N-tosyl-β-alanyl chloride with aluminium chloride between –70 and 20° gave 1,3,4,5-tetrahydro-8-methoxy-2-tosylbenz[c]azepin-5-one (86%), which showed the properties expected of a monoaryl ketone. Bromination in the 1-position gave labile bromides, whereas the 4-bromo-derivatives were stable crystalline solids. The 4-monobromo-compound underwent ready dehydrobromination to give 1,5-dihydro-8-methoxy-2-tosylbenz[c]azepin-5-one.