反应详情

A mixture of 3.13 g (6.27 mmol) of the compound obtained in Step B, 60 ml of a 1:1 mixture of dichloromethane-methanol and 0.52 ml (6.90 mmol) of 50% sodium hydroxide solution was stirred at room for 1.5 h. After filtration the reaction mixture was concentrated, the residue was treated with water and recrystallized from three fold dimethylformamide containing 10% water to yield 1.96 g (77%) of the title compound; Mp.: 261-263° C.

1. filtrationAfter filtration the reaction mixture
2. concentrationwas concentrated
3. additionthe residue was treated with water
4. customrecrystallized from three fold dimethylformamide containing 10% water