反应详情

温度

140 °C

6-Methoxy-2H-3,1-benzoxazine-2,4(1H)-dione (23 g, 119 mmol) and (2,4-dimethoxy-benzylamino)-acetic acid 1 (27 g, 120 mmol) were suspended in p-xylene (500 mL) and heated under argon at reflux (140° C.) for 2 h. The hot solution was allowed to cool to rt, while spontaneous crystallization occurred. The crystals were filtered off and washed with p-xylene (50 mL). Yield: 39 g (92%). mp 196° C. m/z 356 (M).

1. temperatureheated under argon
2. temperatureto cool to rt, while spontaneous crystallization
3. filtrationThe crystals were filtered off
4. washwashed with p-xylene (50 mL)