反应详情

To a solution of 3-tert-butyloxycarbonylamino-4-(2methylphenyl) -7,8-dihydro-6H-cyclopenta [g] [1 ]benzopyran-2-one (2.05 g) in dichloromethane (20 ml) was added trifluoroacetic acid (10 ml) dropwise with ice-cooling. The mixture was stirred under ice-cooling for 1 hour, after which the solvent was distilled off. The residue was diluted with water, neutralized with saturated aqueous solution of NaHCO3 and extracted with chloroform. The extract was washed with water and dried (MgSO4) and the solvent was distilled off to give crystals of 3-amino-4-(2-methylphenyl)-7,8-dihydro-6H-cyclopenta[g] [1]-benzopyran-2-one (1.5 g, 98.4%). Recrystallization from ethanol-dichloromethane gave colorless prisms, m.p. 275°-276° C.

1. temperaturecooling
2. temperaturecooling for 1 hour
3. distillationafter which the solvent was distilled off
4. additionThe residue was diluted with water
5. extractionextracted with chloroform
6. washThe extract was washed with water
7. dry with materialdried (MgSO4)
8. distillationthe solvent was distilled off