反应 #1543070

反应方程式

Water

Acetic anhydride

dimethylaminopyridine

Methyl 5-nitrobenzofuran-2-carboxylate

→

powder 9

收率 61.0%

Methyl 5-acetaminobenzofuran-2-carboxylate

收率 61.0%

溶剂

ethyl acetate

反应条件

后处理

1. 1
   过滤The reaction mixture was filtered
2. 2
   其他the solvent was removed in vacuo
3. 3
   workup.DISSOLUTIONThe residue was dissolved in acetone (10 mL)
4. 4
   其他was used without further purification
5. 5
   萃取the mixture was extracted with ethyl acetate (40 mL×5)
6. 6
   其他The solution was dried
7. 7
   其他was removed in vacuo

实验过程

Methyl 5-nitrobenzofuran-2-carboxylate (13, 0.5 g, 2.26 mmol, made from 5-nitrobenzofuran-2-carboxylic acid, Trans World Chemicals, Inc.) was dissolved in ethyl acetate (40 mL) and 5% Pd/C (30 mg) was added. The reaction mixture was hydrogenated for 1 h at room temperature at a pressure of 60 lb/inch2. The reaction mixture was filtered and the solvent was removed in vacuo. The residue was dissolved in acetone (10 mL) and was used without further purification. Acetic anhydride (0.86 mL, 9.1 mmol) and dimethylaminopyridine (20 mg) was added. The solution was stirred for 1 h at room temperature. Water (20 mL) was added and the mixture was extracted with ethyl acetate (40 mL×5). The solution was dried using sodium sulfate and solvent was removed in vacuo. A grey powder 9 was obtained (321 mg, 61% yield). An analytical sample was recrystallized in ethyl acetate. mp: 158°-159° C. 1H NMR (DMSO-d6, ppm): 10.03 (s, 1 H, NH), 8.19-8.18 (d, 1 H, J=1.6 Hz, Ar--H), 7.76-7.75 (d, 1 H, J=1.1 Hz, Ar--H), 7.65-7.63 (d, 1 H, J=9.0 Hz, Ar--H), 7.55-7.52 (dd, 2 H, J=2.3, 8.9 Hz, Ar--H), 3.89 (s, 1 H, OCH3), 2.07 (s, 3 H, CH3CO), Anal. (C12H11 NO4), C, H, N.

来源