反应详情

3-Hydroxy-4-nitrobenzoic acid (6.06 g, 32.1 mmol), HOBt (0.876 g, 6.42 mmol, 0.2 eq.) and ethylamine hydrochloride (3.03 g, 35.3 mmol, 1.1 eq.) were suspended in DMF (80 ml), triethylamine (5.82 ml, 41.7 mmol, 1.3 eq.) was added, WSC (6.91 g, 35.3 mmol, 1.1 eq.) was added, and the mixture was stirred at room temperature for 14.5 hr. The reaction mixture was suspended in ethyl acetate-hexane (4:1, 250 ml) and washed sequentially with 8% acidic solution of ammonium chloride in water (×2), 10% aqueous ammonium chloride solution and saturated brine. The aqueous layers were each extracted with ethyl acetate-hexane (4:1, 150 ml). The organic layers were combined, dried over anhydrous sodium sulfate, and concentrated, and the residue was diluted with diethyl ether. The precipitate was collected by filtration, washed with diethyl ether and dried to give the title compound as a yellow powder (5.14 g, 24.5 mmol, 76.2%).

1. washwashed sequentially with 8% acidic solution of ammonium chloride in water (×2), 10% aqueous ammonium chloride solution and saturated brine
2. extractioneach extracted with ethyl acetate-hexane (4:1, 150 ml)
3. dry with materialdried over anhydrous sodium sulfate
4. concentrationconcentrated
5. additionthe residue was diluted with diethyl ether
6. filtrationThe precipitate was collected by filtration
7. washwashed with diethyl ether
8. customdried