反応 #61155

反応方程式

hydrochloric acid

2-formyl-5-furancarboxylic acid

hydroxylamine hydrochloride

acetic anhydride

→

title compound

収率 46.0%

5-Cyano-furan-2-carboxylic acid

収率 46.0%

溶媒

pyridine

water

反応条件

後処理

1. 1
   温度After cooling to 60° C.
2. 2
   workup.STIRRINGthe mixture was stirred at RT for 70 h
3. 3
   抽出extracted with 3:1 dichloromethane-isopropanol (8×100 mL)
4. 4
   洗浄The combined organic layers were washed with water (100 mL), brine (100 mL)
5. 5
   乾燥dried over anh sodium sulfate
6. 6
   濃縮concentrated in vacuo

実験手順

To 2.8 g of 2-formyl-5-furancarboxylic acid (20 mmol) and 2.7 g of hydroxylamine hydrochloride (40 mmol) under Ar was added and dry pyridine (50 mL). The mixture was heated to 85° C., acetic anhydride (40 mL) was added and the mixture was stirred for 3 h. After cooling to 60° C., water (250 mL) was added and the mixture was stirred at RT for 70 h. The mixture was acidified to pH 2 with concentrated hydrochloric acid and extracted with 3:1 dichloromethane-isopropanol (8×100 mL). The combined organic layers were washed with water (100 mL), brine (100 mL), dried over anh sodium sulfate and concentrated in vacuo to afford the title compound as a tan solid (1.26 g, 46%). 1H-NMR (CD3OD; 400 MHz): δ 14.05 (br s, 1H), 7.74 (d, 1H, J=3.8 Hz), 7.42 (d, 1H, J=3.8 Hz).

出典