title: A search for new drugs in the group of xanthine derivatives. XXXV. A new method of synthesis of 6,7,8,9-tetrahydropyrimido (2,1-f)-purine-2,4-(1H,3H)-dione system.
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D008722:Methods; D011687:Purines / Q000138:chemical synthesis*; D011743:Pyrimidines / Q000138:chemical synthesis; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D014970:Xanthines
chemical_list: D011687:Purines; D011743:Pyrimidines; D014970:Xanthines