Azabenzocycloheptenones. Part XIII. Ring expansion of 1,2-dihydroquinoline derivatives

Abstract

Dibromocarbene reacts with 4-ethoxy-1,2-dihydro-1-p-tolylsulphonylquinolines to give adducts which can be converted in fair yield into 4-bromo-5-ethoxy-1-p-tolylsulphonyl[1]benzazepines and in poor yield into 4-bromo-1,2-dihydro-1-p-tolylsulphonyl[1]benzazepin-5-ones. 4-Ethoxy-1,2-dihydro-2-methyl-1-p-tolylsulphonylquinolines do not react with dihalogenocarbenes but an N-methylsulphonyl analogue reacts with dibromocarbene and the adduct can be ring-expanded to 2-methyl[1]benzazepine derivatives.