反应详情

A stirred mixture of 2.47 g of ethyl-2-oxo-4-phenyl-2H-pyrimido[2,1-b]benzothiazole-8-acetate, 100 ml of methanol and a solution of 2.47 g of potassium carbonate in 20 ml of water was kept at ambient temperature overnight. The methanol was evaporated and the residue was diluted with water, then acidified with concentrated hydrochloric acid. The precipitate was collected, dried, and crystallized twice from methanol to obtain 1.72 g (75% yield) of 2-oxo-4-phenyl-2H-pyrimido[2,1-b]benzothiazole-8-acetic acid as yellow plates.

1. customThe methanol was evaporated
2. additionthe residue was diluted with water
3. customThe precipitate was collected
4. customdried
5. customcrystallized twice from methanol