Quinoline → Ethyl 5-cyano-1-benzothiophene-7-carboxylate

関与物質

反応条件

反応手順

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).

情報源と証拠