Acetic Acid → Dimethyl 3-(cyanomethylidene)pentanedioate

Participants

Reaction Steps

To a solution of 3-oxo-pentanedioic acid dimethyl ester (523 g) in toluene (750 mL), cyanoacetic acid (511 g), NH4OAc (46.3 g) and acetic acid (90.1 g) were added and heated at reflux with dehydrating by Dean-Stark apparatus for 8 h. After cooling to room temperature, the reaction mixture was washed with water, saturated aqueous NaHCO3 solution and brine. The organic phase was dried over MgSO4, filtered, and concentrated under reduced pressure to give crude 3-cyanomethylene-pentanedioic acid dimethyl ester (403 g) as an oil. 1H NMR (200 MHz, CDCl3) δ ppm 3.39 (d, J=0.88 Hz, 2 H), 3.62 (s, 2 H), 3.72 (s, 3 H), 3.74 (s, 3 H), 5.51 (s, 1 H).

Provenance & Evidence