反应详情

Ethyl 4-fluoro-3-nitrobenzoate (160 g, 0.752 mol) prepared in the Step 1-1-1 was suspended in ethanol (500 ml). Triethylamine (91.4 g, 0.903 mol) was added to the suspension, and under an ice cooling, piperidine (76.9 g, 0.903 mol) was slowly added thereto. After the mixture was stirred at a room temperature for 2 hours, a saturated sodium bicarbonate solution was added to the mixture, and the resulting mixture was subjected to extraction with ethyl acetate. The ethyl acetate layer was washed with a saturated sodium bicarbonate solution and a saturated saline solution in order, and then dried over anhydrous magnesium sulfate and concentrated. The concentrate was purified by silica gel column chromatography (n-hexane:ethyl acetate=4:1 to 3:1) to give the title compound (222 g, quantitative) as a poppy-red oily substance.

1. extractionthe resulting mixture was subjected to extraction with ethyl acetate
2. washThe ethyl acetate layer was washed with a saturated sodium bicarbonate solution
3. dry with materiala saturated saline solution in order, and then dried over anhydrous magnesium sulfate
4. concentrationconcentrated
5. customThe concentrate was purified by silica gel column chromatography (n-hexane:ethyl acetate=4:1 to 3:1)