反应详情

温度

60 °C

Methyl 7-chloro-2-methyl-s-triazolo[1,5-a]pyrimidine-5-carboxylate (0.80 g) (3.53 mmol) are suspended in 35 ml of methanol and treated with 0.78 g (10.6 mmol) of sodium hydrogen sulphide hydrate. After stirring at 60° C. for 5 hours the mixture is concentrated and the residue is dissolved in 20 ml of water. The solution is acidified to pH 3 with 3N aqueous hydrochloric acid. The precipitated product is filtered off under suction and washed with water and methanol. After recrystallization from methanol/dichloromethane there is obtained 0.66 g of methyl 7-mercapto-2-methyl-s-triazolo[1,5-a]pyrimidine-5-carboxylate as yellow crystals of melting point 237° C. (dec.).

1. concentrationis concentrated
2. dissolutionthe residue is dissolved in 20 ml of water
3. filtrationThe precipitated product is filtered off under suction
4. washwashed with water and methanol
5. customAfter recrystallization from methanol/dichloromethane there