反应详情

1 g (0.0068 mol) of ethyl orthoformate is added to a solution of 1.1 g (0.00315 mol) of ethyl 2,5-difluoro-4-(pyrrol-1-yl)benzoylacetate in 3 ml of acetic anhydride and the mixture is refluxed for 3 hours. It is evaporated to dryness, the residue is dissolved in 10 ml of ethanol, 0.3 ml (0.0034 mol) of cyclopropylamine is added and the mixture is left at room temperature for 1 hour. It is evaporated to dryness and the oily residue is extracted with 3×30 ml of boiling hexane. The hexane fractions are concentrated to 20 ml and left for 12 hours at 5° C. to give 0.41 g of crystals melting at 90°-2° C.

1. temperaturethe mixture is refluxed for 3 hours
2. customIt is evaporated to dryness
3. dissolutionthe residue is dissolved in 10 ml of ethanol
4. customIt is evaporated to dryness
5. extractionthe oily residue is extracted with 3×30 ml of boiling hexane
6. concentrationThe hexane fractions are concentrated to 20 ml
7. waitleft for 12 hours at 5° C.