反应详情

A mixture of 2-(1,2-dihydroxyethyl)-7,8-dihydroquinolin-5(6H)-one (Preparation 54D, 0.226 g, 1.09 mmol), 2,2-dimethoxypropane (0.402 mL, 3.27 mmol), and (1R)-(−)-camphorsulfonic acid (0.051 g, 0.22 mmol) in acetone (6 mL) was stirred at room temperature overnight. The reaction mixture was quenched with a saturated aqueous solution of sodium bicarbonate and concentrated under reduced pressure. The aqueous residue was diluted with ethyl acetate, washed with a saturated aqueous solution of sodium bicarbonate and brine. The organic layer was collected, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were dried over anhydrous sodium sulfate and concentrated and purified by flash silica gel chromatography using a mixture of ethyl acetate in hexane (50%) to afford 2-(2,2-dimethyl-1,3-dioxolan-4-yl)-7,8-dihydroquinolin-5(6H)-one (0.182 g, 0.736 mmol, 68% yield) as a clear, colorless oil. The product had an HPLC ret. time=1.75 min. (condition A); LC/MS M+1=247.9.

1. customThe reaction mixture was quenched with a saturated aqueous solution of sodium bicarbonate
2. concentrationconcentrated under reduced pressure
3. additionThe aqueous residue was diluted with ethyl acetate
4. washwashed with a saturated aqueous solution of sodium bicarbonate and brine
5. customThe organic layer was collected
6. extractionthe aqueous layer was extracted with ethyl acetate
7. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
8. concentrationconcentrated
9. custompurified by flash silica gel chromatography
10. additiona mixture of ethyl acetate in hexane (50%)