2,4,6,8-Tetrahydroxy-Pyrimido-(5,4d)Pyrimidine is prepared by the reaction of 5-amino-2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid and urea. The specific synthesis steps are as follows:
5-amino-2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid was charged into a two nicked flask, Urea (7.7 g, 128.0 mmol) was added dropwise with 125 ml of NaOH solution (500 g of sodium hydroxide + 1500 g of purified water) After dripping rapidly warming to 100 ° C,Insulation for one hour; continue to stir 3h,(25 ° C), filtered to obtain a solid, add purified water 250ml, heated to 60 ° C, heat lh, and then add dilute hydrochloric acid to ΡΗ = 4, cooled to room temperature filtration, washed and dried to obtain pyrimidine [5 , 4-d] pyrimidine-2,4,6,8-tetraol (tetrahydroxy), and recrystallized (ethanol solvent) to give 10.9 g in 86.9% yield.
