反应详情

温度

70 °C

To a solution of 4-(6-nitroindol-1-yl)benzoic acid ethyl ester (0.53 g) in N,N-dimethylformamide (6 mL) was added phosphoryl chloride (0.31 g) under ice cooling and this mixture was stirred at 70° C. overnight. After cooling to ambient temperature, to this reaction mixture was added 2 mol/L aqueous sodium hydroxide solution and this mixture was stirred at 30 minutes. This reaction mixture was poured into 1 mol/L hydrochloric acid, and the precipitated solid was collected by filtration, and washed with water and n-hexane, and dried under reduced pressure at 40° C. to give 4-(3-formyl-6-nitroindol-1-yl)benzoic acid ethyl ester (0.46 g). To a solution of this aldehyde (0.46 g) in tetrahydrofuran (10 mL) were added hydroxylamine hydrochloride (0.19 g) and pyridine (0.43 g) at room temperature, and this mixture was stirred at 80° C. for 8 hours. To this reaction mixture was added acetic anhydride (0.42 g) at 80° C., this mixture was stirred at same temperature overnight. After cooling to ambient temperature, to this reaction mixture was added 1 mol/L hydrochloric acid, and the precipitated solid was collected by filtration. This solid was washed with water, n-hexane and diethyl ether to give the title compound (0.13 g).

1. temperatureAfter cooling to ambient temperature, to this reaction mixture
2. stirringthis mixture was stirred at 30 minutes
3. filtrationthe precipitated solid was collected by filtration
4. washwashed with water and n-hexane
5. customdried under reduced pressure at 40° C.