反应详情

A stirred solution of 5-fluoroisatin (39 g, 0.236 mol) in NaOH (5%, 500 mL) was treated dropwise over 10 min with 30% H2O2 (57 g, calculated to contain 17 g, 0.5 mol). After another 20 min of being stirred, during which became warm and effervesced, the solution was cooled in an ice-bath and acidified to pH=4 with 3 M HCl. The precipitated solid was collected and dried in air to obtain 2-amino-5-fluoro-benzoic acid 1 as a beige powder (29.6 g, 80%). 1H NMR (DMSO-d6) δ 7.3-8.2 (m, 2H), 7.08 (d, J=9 Hz, 1H), 6.63 (d, J=9 Hz, 2H), 2.13 (s, 3H).

1. temperaturebecame warm
2. temperatureeffervesced, the solution was cooled in an ice-bath
3. customThe precipitated solid was collected
4. customdried in air