title: V-Triazolo(4,5-d)pyrimidines (8-azapurines). XII. Cleavage of the pyrimidine ring in 8-azapurines by some active methylene reagents and eventual closure to give v-triazolo(4,5-b)pyridines.
mesh_terms: D001372:Aza Compounds; D003500:Cyclization; D009682:Magnetic Resonance Spectroscopy; D011687:Purines; D011725:Pyridines / Q000138:chemical synthesis*; D013056:Spectrophotometry, Ultraviolet; D014230:Triazoles / Q000138:chemical synthesis
chemical_list: D001372:Aza Compounds; D011687:Purines; D011725:Pyridines; D014230:Triazoles