The products of the photolysis of 2-(4-alkyI(or phenyl)piperazino)-3-amino-1,4-naphthoquinones,their structures and subsequent thermal transformations

Photolysis of 2-(4-alkyI(phenyl)piperazino)-3-amino-1,4-naphthoquinones affords 2-alkyl (phenyl)-1,2,3,4,12,12a-hexahydronaphtho2,34,5]imidazo1,2-a]pyrazine-6,11-diols which recyclize at elevated temperatures to yield 1,2,3,4-tetrahydro-13-alkyl(phenyl)-3,1-(iminoethano) benzog]quinoxaline-5,10-diols. The latter are oxidated with atmospheric oxygen to the corresponding diones. On the basis of deuterium exchange data a mechanism for the recyclization is proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 944–949, May, 1993.