反应详情

Methyl 7-mercapto-2-methyl-s-triazolo[1,5-a]pyrimidine-5-carboxylate (500 mg) (2.23 mmol) are suspended in 100 ml of absolute methanol. 2.95 mg (8.9 mmol) of hydroxylamine are added within 4 days while stirring. The reaction mixture is acidified (pH 6) with 3N aqueous hydrochloric acid. The product is filtered off under suction and washed in succession with water, methanol and diethyl ether. There are obtained 540 mg of N-hydroxy-7-mercapto-2-methyl-s-triazolo[1,5-a]pyrimidine-5-carboxamide as yellow crystals of melting point 178°-179° C.

1. filtrationThe product is filtered off under suction
2. washwashed in succession with water, methanol and diethyl ether