反应详情

温度

100 °C

Sodium 2-hydroxy-4-aminobenzoate (76 g, 0.437 mole) was dissolved in water (2-300 ml) and concentrated hydrochloric acid (36.2 ml) was added after which the precipitated crystalline free acid was isolated by filtration. The acid was suspended in water (700 ml), acetic anhydride (48 ml) was added and the mixture was heated to about 100° C. (supplied with a reflux condenser) for 15 minutes under nitrogen. After cooling, the crystalline material was filtered off and dried in vacuo to give the title compound (48 g, 56%), m.p. 221°-223° C. Found (Calc. for C9H9NO4) C 55.14 (55.38), H 4.73 (4.62), N 7.12 (7.18).

1. customwas isolated by filtration
2. temperatureAfter cooling
3. filtrationthe crystalline material was filtered off
4. customdried in vacuo