反应详情

0.7 g (1.25 mmol) of methyl 4-(cyanoethoxycarbonylmethylhydrazino)-2-[3-(4,6-dimethoxypyrimidin-2-yl)ureidosulfonyl]benzoate, sodium salt, are dissolved in 15 ml of water. The few undissolved components are filtered off and the filtrate is acidified to pH 1 using 2N hydrochloric acid. The precipitated solid is filtered off with suction, washed with water and dried. This gives 0.5 g (75% of theory) of methyl 4-(cyanoethoxycarbonyl-methyldenhydrazino)-2-[3-(4,6-dimethoxypyrimidin-2-yl) ureidosulfonyl]benzoate of m.p. 145° C. (decomp.)

1. filtrationThe few undissolved components are filtered off
2. filtrationThe precipitated solid is filtered off with suction
3. washwashed with water
4. customdried