Isoelectronic analogs of indolizine

The structure of the perchlorates of 2,3,4-trimethyl-, 1,2,4-trimethyl-, 1,2,3,4-tetramethyl-, and 1,4-dimethyl-2-phenylpyrrolo1, 2-a]benzimidazoles in trifluoroacetic acid has been studied by the PMR method. It has been established that in all cases on salt formation the proton adds to the carbon atom in position 1. The molecular diagram of pyrrolo1,2-a]benzimidazole has been calculated by the MO LCAO method.For part VI, see 1].