CYCLOADDITION REACTIONS OF 7-SUBSTITUTED ACENAPHTHO[1,2-D]PYRAZOLO[1,2-A]BENZOTRIAZOLES WITH DIMETHYL ACETYLENEDICARBOXYLATE

The reactions of the title 7-phenyl- and 7-methylacenaphthopyrazoloben zotriazoles (triazapentalenes) with dimethyl acetylenedicarboxylate ga ve a mixture of the corresponding initial azomethine imidic cycloadduc t and its isomeric pyrazinopyrimidine, whose yields greatly depended o n the reaction conditions. Structures of both the initial and isomeric products were determined by X-ray crystallographic analyses. The init ial cycloadduct readily isomerized to the pyrazinopyrimidine. It has b een found that the methyl-substituted pyrazinopyrimidine underwent the Micheal-type addition reaction.