4'-Cyanoacetophenone → HCID 86638943, compound

Participants

Reaction Steps

A solution of n-propylpyrazine (compound 2, 912 mg, 7.46 mmol) in tetrahydrofuran (5 mL) was added drop-wise, over a period of seven minutes, to a solution of sodium bis(trimethylsilyl)amide (2M solution in THF; 13 mL, 26 mmol, 3.5 equiv) at 20° C. A deep, purple-red solution was obtained and the temperature fell to 16.4° C. A solution of 4-acetylbenzonitrile (compound 3, 1.08 g, 7.4 mmol) in tetrahydrofuran (5 mL) was added, over a period of 18 minutes, at 13.3° C. The temperature fell to 12.6° C. and a brown solution ensued. The mixture was stirred at room temperature for one hour, heated to about 35° C. for six hours, then left to stir at room temperature for about 60 hours. The mixture was poured into aqueous saturated sodium bicarbonate (200 mL) and extracted with ethyl acetate (2×150 mL). The ethyl acetate was washed with water (100 mL) and concentrated on the Buchi at a bath temperature of 40° C. and from 80 to 10 torr to give a deep-yellow solid. The solid was triturated with diethyl ether (25 mL), filtered and washed with ether (25 mL). The solid was air dried to give 600 mg (30.3%) of compound 4 as a yellow solid: 1H NMR (300 MHz, CDCl3, FIG. 1) δ 8.5 (1H, d, J=2 Hz), 8.15 (2H, d, J=8 Hz), 8.1 (1H, d, J=3 Hz), 7.9 (2H, d, J=8 Hz), 3.1 (2H, q, J=9 Hz), 2.7 (3H, s), 1.4 (3H, t, J=9 Hz).

Provenance & Evidence