Synthesis of the Parent Systems of Dipyrrolo[1,2-a:2',1'-c]pyrazine and of Dipyrrolo[1,2-a:2',1'-c]quinoxaline

A synthesis of the title compounds is described starting from 2,3 dimethylpyrazine and 2,3-dimethylquinoxaline, respectively. The two pyrrole rings are formed in two subsequent steps by condensation of the methyl groups of the starting azines with the carbonyl groups of the ethyl pyruvate moiety linked to the ring nitrogen atoms. Deuterium exchange reactions of dipyrrolo[1,2-a:2',1'-c]pyrazine are also reported