Thermal opening of the diaziridine fragment in 1-methyl-and 1,3,3-trimethyl-1,3,4,8b-tetrahydro-[1,2]diazirino[3,1-<Emphasis Type="Italic">a</Emphasis>]isoquinolines in the presence of n-arylmaleimides

The thermal opening of the diaziridine ring in 1-methyl-and 1,3,3-trimethyl-1,3,4,8b-tetra-hydro1,2]diazirino3,1-a]isoquinolines in the presence of N-arylmaleimides leads to the predominant or exclusive formation of the trans isomers of the products of 1,3-dipolar cycloaddition. In the absence of dipolarophile, the conversion of the starting diaziridines is incomplete over the same time period, while the thermolysis products are N-3,4-dihydro-2(1H)-isoquinolyl]-and N-3,3-dimethyl-3,4-di-hydro-2(1H)-isoquinolyl]-N-methyleneamines formed as the result of isomerization of intermediate labile azomethineimines. Dedicated to the memory of A. A. Potekhin. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1071–1079, July, 2008.