反应详情

Triethylamine (1.2 ml) was added dropwise to a mixture of 4-(2-methylphenyl)-2-oxo-2,6,7,8-tetrahydrocyclopenta[g][1]benzopyran-3-carboxylic acid (2.56 g), DPPA (2.64 g) and benzene (32 ml). The mixture was stirred at room temperature for 30 minutes and, then, on reflux for 30 minutes. Then, 2,4-difluoroaniline (1.0 ml) was added and the mixture was further refluxed for 30 minutes. The reaction mixture was washed with water, 1N HCl and water in the order mentioned and, then, dried (MgSO4). The solvent was then distilled off to give N-(2,4-difluorophenyl)-N'-[4-(2-methylphenyl)-2-oxo-2,6,7,8-tetrahydrocyclopenta[g][1]-benzopyran-3-yl]urea as oil. The oil was crystallized by addition of isopropyl ether (3.4 g, 95.2%). Recrystallization from acetone gave colorless prisms, m.p. 223°-224° C.

1. temperatureon reflux for 30 minutes
2. temperaturethe mixture was further refluxed for 30 minutes
3. washThe reaction mixture was washed with water, 1N HCl and water in the order
4. dry with materialdried (MgSO4)
5. distillationThe solvent was then distilled off