Synthesis and reactions of pyrrolo[2,1-c][1,2,4]benzotriazine and 4-oxo-4H-pyrrolo[2,1-c][1,4]benzoxazine

Abstract

The reactivities of pyrrolo[2,1-c][1,2,4]benzotriazine (3) and of 4-oxo-4H-pyrrolo[2,1-c][1,4]benzoxazine (6) to some typical electrophiles are studied and compared to those of pyrrolo[1,2-a]quinoxaline (2). The preferred site of substitution in all three compounds is position 1; in compounds (2) and (3), C-3 is the second most favoured position for substitution but for compound (6) this is found to be position 2. The experimentally determined sites of halogenation are the same as those predicted by molecular orbital calculations.