反应详情

A mixture of methyl 2-oxo-5-chloro-6-bromo-3-benzothiazolineacetate (2.0 g), methanol (250 ml) and 10% sodium hydroxide aqueous solution (2.5 ml) was refluxed with stirring for 1.5 hours and then cooled with ice-water to give crystals, which were separated by filtration. The filtrate was concentrated under reduced pressure to give crystals. The combined crystals were dissolved in water (80 ml) under heating and then insoluble materials were removed by filtration. The filtrate was adjusted at pH 2-3 with 10% hydrochloric acid and cooled to give crystals, which were separated by filtration, washed with water and dried to give crystalline 2-oxo-5-chloro-6-bromo-3-benzothiazolineacetic acid (1.5 g).

1. temperaturewas refluxed
2. customto give crystals, which
3. customwere separated by filtration
4. concentrationThe filtrate was concentrated under reduced pressure
5. customto give crystals
6. temperatureunder heating
7. custominsoluble materials were removed by filtration
8. temperaturecooled
9. customto give crystals, which
10. customwere separated by filtration
11. washwashed with water
12. customdried