Annelation of drotaverine by <Emphasis Type="Italic">p</Emphasis>-quinones to form hydroxyindolo- and hydroxybenzindoloisoquinoline derivatives

1-(3, 4-Diethoxybenzyl)-6, 7-diethoxy-3, 4-dihydroisoquinoline (drotaverine, 1a) reacts with p-benzoquinone (2) and p-naphthoquinone (3) in nitromethane or during fusion to give 5-(3, 4-diethoxyphenyl)-7, 8-diethoxy-3-hydroxy-5a, 10, 11, 12-tetrahydroindolo2, 1-a]isoquinoline (4) and 7-(3, 4-diethoxyphenyl)-9, 10-diethoxy-5-hydroxy-7a, 12, 13, 14-tetrahydrobenzg]indolo2, 1-a]isoquinoline (5), respectively. Compounds 4 and 5 are smoothly alkylated at the oxygen atom in the presence of bases. The structure of one alkylation product, viz., 3-allyloxy-5-(3, 4-diethoxyphenyl)-7, 8-diethoxy-5a, 10, 11, 12-tetrahydroindolo2, 1-a]isoquinoline, was established by X-ray diffraction analysis.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 761–769, March, 2005.