反应详情

To a solution of 4.81 g (27.8 mmol) of commercially available 2-amino-4, 5-difluorobenzoic acid in 20 ml of ethanol were added 1.92 ml (19.4 mmol) of piperidine and 2.25 g (27.8 mmol) of 1,3,5-triazine, followed by heating under reflux in an atmosphere of argon for 6.5 hours. After the reaction mixture was allowed to cool to room temperature, the solvent was evaporated. To the residue was added water, and the resulting mixture was neutralized with 4 N hydrochloric acid. The precipitated crystals were collected by filtration, washed with water, and dried to give 4.37 g (86%) of 6,7-difluoro-4(3 H)-quinazolone.

1. temperatureby heating
2. temperatureunder reflux in an atmosphere of argon for 6.5 hours
3. customthe solvent was evaporated
4. additionTo the residue was added water
5. filtrationThe precipitated crystals were collected by filtration
6. washwashed with water
7. customdried