反应详情

温度

180 °C

Methyl 3-amino-2-hydroxybenzoate (4.4 g, 26 mmol) and 4-methylbenzoic acid (3.6 g, 26.0 mmol) were added to the polyphosphoric acid (20 g). The mixture was heated at 180° C. for 2 hr, and then cooled, poured into water, extracted with ethyl acetate, washed with saturated sodium bicarbonate solution, brine, dried over anhydrous sodium sulfate and condensed to obtain methyl 2-p-tolylbenzo[d]oxazole-7-carboxylate as a white solid (2.1 g, yield 30%). LC-MS (ESI) m/z 268 [M+1]+.

1. temperaturecooled
2. extractionextracted with ethyl acetate
3. washwashed with saturated sodium bicarbonate solution, brine
4. dry with materialdried over anhydrous sodium sulfate and condensed