反应详情

4.2 g of ethyl 3,5-dioxocyclohexanecarboxylate and 3.4 g of triethylamine were dissolved in 50 ml of dichloromethane, to which was added dropwise 2.9 g of propionyl chloride under stirring at room temperature. The resultant mixture was allowed to react at ambient temperature for 2 hours, after which the reaction solution was washed with water and admixed with a dilute aqueous sodium bicarbonate solution to remove the acidic matters from the reaction solution. The organic layer was then separated from the aqueous phase, dried and concentrated to a small volume. The concentrated solution was taken up in 20 ml of toluene, followed by addition of 0.5 g of 4-N,N-dimethylaminopyridine and heating the mixture at 85° C. for 3 hours. Thereafter, the toluene was removed from the reaction solution by distillation under reduced pressure, and the residue was chromatographed on silica gel using benzene as developing solvent to afford 2.5 g of the title compound (Compound No. 9 of Table 1) as colorless flakes having a melting point of 55°- 56° C.

1. customto react at ambient temperature for 2 hours
2. washafter which the reaction solution was washed with water
3. customto remove the acidic matters from the reaction solution
4. customThe organic layer was then separated from the aqueous phase
5. customdried
6. concentrationconcentrated to a small volume
7. additionfollowed by addition of 0.5 g of 4-N,N-dimethylaminopyridine
8. temperatureheating the mixture at 85° C. for 3 hours
9. customThereafter, the toluene was removed from the reaction solution by distillation under reduced pressure
10. customthe residue was chromatographed on silica gel