反应详情

A mixture of 10.25 g of 2-amino-3-trifluoromethylbenzoic acid, 20 ml of toluene and 20.3 g of 2-chlorohexanoic acid chloride (prepared according to J. Org. CHem., Vol. 40 (1975), p. 23420) was refluxed for one hour and then toluene and excess acid chloride were removed by distillation. The residue was chromatographed over silica gel and eluted with methylene chloride and then by chromatography under pressure. Elution with a 1-1 ethyl acetate-petroleum ether (b.p.=60°-80° C.) mixture yielded 8.4 g of 2-(1-chlorobutyl)-8-trifluoromethyl-4H-3,1-benzoxazine-4-one in the form of an oil which was used as is for the next step.

1. temperaturewas refluxed for one hour
2. customtoluene and excess acid chloride were removed by distillation
3. customThe residue was chromatographed over silica gel
4. washeluted with methylene chloride
5. washElution with a 1-1 ethyl acetate-petroleum ether (b.p.=60°-80° C.) mixture