反应详情

温度

-78 °C

A solution of 1.04 ml (20 mmol) of acetonitrile in 7 ml of tetrahydrofuran was added to a solution of 12.5 ml of 1.6 M n-butyl lithium in hexane (20 mmol) in 25 ml of tetrahydrofuran at −78° C. After 15 minutes, a solution of 2.019 g (9.5 mmol) of 3-(dimethylamino-methyleneamino)-thiophene-2-carboxylic acid methyl ester in 25 ml of tetrahydrofuran was added dropwise over 1 h. The reaction mixture was stirred at −78° C. for 30 minutes, and then allowed to warm to room temperature. After stirring at room temperature for 1 h, the reaction mixture was cooled to −50° C. and 1.4 ml of acetic acid was added. The resulting mixture was partitioned between ethyl acetate and water. The organic layer was dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was recrystallized from acetone and hexanes to give 0.668 g (40%) of red-brown solid. 1H NMR (300 MHz, DMSO-d6) δ 8.38 (s, 1H), 7.94 (d, J=5.4 Hz, 1H), 7.25 (d, J=6 Hz, 1H); LC-MS (ESI) m/z 177.0 (M+1).

1. temperatureto warm to room temperature
2. stirringAfter stirring at room temperature for 1 h
3. temperaturethe reaction mixture was cooled to −50° C.
4. customThe resulting mixture was partitioned between ethyl acetate and water
5. dry with materialThe organic layer was dried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe residue was recrystallized from acetone and hexanes