反应详情

To the solution of 6.5 g (0.05 mole) of 5-amino-3-methylthio-1H-1,2,4-triazole, 2.5 ml of acetic acid and 12.5 ml of dimethylformamide 9.4 g (0.05 mole) of ethyl 3-oxo-3,4,5,6-tetrahydro-2H-thiopyrane-2-carboxylate are added and the reaction mixture is boiled for 60 minutes. The precipitated product is filtered off from the hot solution, then washed with acetic acid and i-propanol and recrystallized from dimethylformamide. Thus 6.5 g (51.1%) of 2-methylthio-5,7,8,9-tetrahydrothiopyrano[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidine-5(10H)-one are obtained. M.p.: higher than 350° C.

1. filtrationThe precipitated product is filtered off from the hot solution
2. washwashed with acetic acid and i-propanol
3. customrecrystallized from dimethylformamide