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Paper | Special issue | Vol 47, No. 2, 1998, pp.871-882
Published online, 1st January, 1970
DOI: 10.3987/COM-97-S(N)97
Convenient Synthesis of Pyrido[4,3-d]-pyrimidine-2,4(1H,3H)-diones

Kosaku Hirota,* Yukio Nakazawa, Yukio Kitade, and Hironao Sajiki

*Labolatory of Medicinal Chemistry, Gifu Pharmaceutical University, 6-1 Mitahora-higashi 5-chome, Gifu 502-8585, Japan


A convenient synthesis of pyrido[4,3-d]pyrimidine-2,4(1H,3H)-diones is described. Treatment of 5-formyl-1,3-dimethyl-6-(2-dimethylamino)vinyluracil (1) with ammonia and hydrazines affords the corresponding pyrido[4,3-d]pyrimidine-2,4(1H,3H)-diones (2 and 3), respectively. Similar reaction of 5-cyano- and 5-ethoxycarbonyluracils (10 and 15) with ammonia led to formation of 5-amino- and 5-hydroxylpyrido[4,3-d]pyrimidine-2,4(1H,3H)-diones (11 and 16), respectively.