REINVESTIGATION OF THE REACTION OF 3-BROMO-4-NITROQUINOLINE 1-OXIDE WITH 1-MORPHOLINOCYCLOHEXENE
Reinvestigation of the reaction of 3-bromo-4-nitroquinoline 1-oxide (2) with 1-morpholinocyclohexene (3) has revealed that the reaction proceeds by a multistep ionic process involving the initial formation of 3-morpholino-4-nitro-2-(2-oxocyclohexyl)quinoline (6) and the subsequent transformation of 6 into 10-nitro-1,2,3,4-tetrahydrobenzofuroquinoline (5).Not only 2 reacts with various enamines in the same way, but also 3-bromo-4-nitropyridine N-oxide (7) undergoes the same type of reactions.