反应详情

温度

0 °C

N-[2-cyano-3-(dimethylamino)prop-2-en-1-ylidene]-N-methylmethanaminium perchlorate (see Collect. Czech. Chem. Commun.; 32; 5; 1967; 1704; 5.84 g, 23.2 mmol) and ethyl 2-thienylacetate (3.95 g, 23.2 mmol) were mixed with quinoline (117 mL) at 0° C. Sodium ethoxide (1.97 g, 27.9 mmol) was added and the mixture was stirred at 0° C. for 30 min and then at room temperature for 15 min. The reaction mixture was heated to 75° C. under nitrogen for 5 h and then cooled to 0° C. Hydrochloric acid (200 mL of 2 M aqueous solution) was added and the mixture extracted thrice with chloroform. The organic solution was washed with brine and then dried over Na2SO4. The solvent was removed by evaporation and the residue flash chromatographed on silica gel (hexane-ethyl acetate, 8:1). There was obtained 2.3 g (43%) of ethyl 5-cyano-1-benzothiophene-7-carboxylate as a pale yellow solid. 1H NMR (300 MHz, CDCl3): 1.5 (t, 3H), 4.5 (qt, 2H), 7.5 (d, 1H), 7.7 (d, 1H), 8.3 (m, 2H).

1. waitat room temperature for 15 min
2. temperatureThe reaction mixture was heated to 75° C. under nitrogen for 5 h
3. temperaturecooled to 0° C
4. extractionthe mixture extracted thrice with chloroform
5. washThe organic solution was washed with brine
6. dry with materialdried over Na2SO4
7. customThe solvent was removed by evaporation
8. customthe residue flash chromatographed on silica gel (hexane-ethyl acetate, 8:1)