Reactions of 1-substituted 8-hydrazinotheobromines with Dicarbonyl Compounds

The study of reactions of 7-substituted 8-hydrazino-3-methylxanthine with β-dicarbonyl compounds

“…Interaction of hydrazinoxantines 10-18 with the excess of acetoacetic ester in glacial acetic acid takes place with the formation of new derivatives of heterocyclic system, namely 8-(3,4-dimethyl-6-oxopyrano[2,3-c]pyrazole-1yl) xanthines (23-31) (Scheme 1) analogously to [11,12]. The IR spectra of 23-31 pyranopyrazoles contain stretching vibrations band of carbonyl group of α-pyran nucleus, which is fi xed at 1780-1744 cm -1 .…”