Dimethyl acetylenedicarboxylate with indazole gave dimethyl indazol-1-ylfumarate and dimethyl α-indazol-1-yl-β-indazol-2-ylsuccinate while the triazoles yielded similar but symmetrical succinates. With diazoaminobenzene the corresponding fumarate and succinate, and dimethyl 2,3-dihydro-2-cis-1,2-dimethoxycarbonylvinyl-1,3-diphenyl-1,2,3-triazole-4,5-dicarboxylate were obtained. The n.m.r. spectra of the compounds are discussed.