反应详情

According to U.S. Pat. No. 5,747,496, the 4,6-dichloro-5-nitro-2-(propylthio)pyrimidine of formula II is prepared by adding propyl iodide to a suspension of 4,6-dihydroxy-2-mercaptopyrimidine in water containing sodium hydroxide; the reaction mixture is stirred for 2 weeks and then the reaction mass is concentrated to half volume; followed by the addition of hydrochloric acid and isolating the product by filtration to produce 2-propylthio-pyrimidine-4,6-diol. The 2-propylthio-pyrimidine-4,6-diol is then reacted with excess fuming nitric acid to produce 5-nitro-2-propylthiopyrimidine-4,6-diol. The 5-nitro-2-propylthiopyrimidine-4,6-diol is reacted with phosphoryl chloride in the presence of N,N-dimethylaniline at reflux to produce a reaction mass. The cooled reaction mass is poured onto ice followed by extracting with diethyl ether to afford a solution; then the combined extracts are dried and concentrated. The residue is chromatographed (SiO2, light petrol) to produce 4,6-dichloro-5-nitro-2-(propylthio)pyrimidine.