An Expeditious Synthesis of 6-Amido-(1H,3H)-Pyrimidine- 2,4-Diones from Uracil-6-Carboxylic Acid

Abstract

2,4-Dichloro pyrimidine-6-carbonylchloride (2) was synthesized by refluxing uracil-6-carboxylic acid
(orotic acid) with phosphorus oxychloride and phosphorus pentachloride. Compound (2) underwent a smooth
coupling reaction with a number of substituted arylamines to yield 2, 4-dichloro-6-amidopyrimidines (8-12) which
were converted to the corresponding 2, 4-dimethoxy-6-amidopyrimidines (13-17) on treatment with sodium
methoxide in methanol. Compounds 13-17 afforded 6-amido-(1H, 3H)-pyrimidine-2, 4-diones (18-22) in good yield
on refluxing with 6 M hydrochloric acid. These pyrimidinone derivatives may exhibit antiviral actitities.