重氮甲烷

5a-acetyl-6,6a-dicarbethoxy-5a,6a-dihydro-6H-cyclopropa<5a,6a>pyrazolo<1,5-a>pyrimidine-3-carbonitrile

ethyl 6-acetyl-3-cyano-7-(1-diazo-2-ethoxy-2-oxoethyl)-4,7-dihydropyrazolo[1,5-a]pyrimidine-7-carboxylate

ethyl 6-acetyl-3-cyano-4,7-dihydropyrazolo[1,5-a]pyrimidine-7-carboxylate

ethyl 3-(((4-cyano-1H-pyrazol-5-yl)amino)methylene)-2,4-dioxopentanoate