Protonation of pyrrolo [1,2-α] Pyrimidine derivatives

The protonation of pyrrolo 1,2-] pyrimidine and 6, 7, 8, 9-tetrahydropyrimido 1, 2-] indole derivatives in CF₃COOH (at –15 to +25° C) and in CF₃COOH/H₂SO₄ (at 25°) was studied by PMR spectroscopy. The investigated compounds form monocations, the structure of which corresponds to the addition of a proton to the carbon atom of th pyrrole fragment in the position to the bridge nitrogen atom.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 686–692, May, 1976.