反应详情

In 250 ml of water are dissolved 25 g of thiosalicylic acid and 60 g of sodium carbonate. Then, under ice-cooling, 38 g of α-bromo-γ-butyrolactone is added dropwise. The mixture is stirred at room temperature for 3 hours. The reaction mixture is made acidic with dilute hydrochloric acid and the resultant precipitate is recovered by filtration, rinsed with water and recrystallized from ethanol. By the above procedure there is obtained 32.5 g of α-[(2-carboxyphenyl)thio]-γ-butyrolactone as colorless prisms melting at 180°-182° C.

1. temperatureThen, under ice-cooling
2. filtrationthe resultant precipitate is recovered by filtration
3. washrinsed with water
4. customrecrystallized from ethanol