反应详情

温度

5 °C

3-Oxo-6-nitro-3,4-dihydro-2H-1,4-benzoxazine. A solution of 2-amino-4-nitrophenol (8.80 g), in methyl isobutyl ketone (30 mL) was treated with sodium bicarbonate (11.5 g) and distilled water (35 mL). The mixture was cooled to 5° C. under a nitrogen atmosphere, treated dropwise with chloroacetyl chloride (5.0 mL) and then heated to reflux for 18 hours. A brown solid was collected from the cooled mixture by filtration. The solid was dried under vacuum at 50° C. for 24 hours yielding benzoxazinone (10.5 g) as a brown solid; mp 235°-236° C.; MS: m/z=195(M+1); NMR: 4.76 (s,2), 7.14 (d,1), 7.74 (d,1), 7.82 (dd,1), 11.07 (broad s,1).

1. distillationdistilled water (35 mL)
2. additiontreated dropwise with chloroacetyl chloride (5.0 mL)
3. temperatureheated
4. temperatureto reflux for 18 hours
5. filtrationA brown solid was collected from the cooled mixture by filtration
6. customThe solid was dried under vacuum at 50° C. for 24 hours