Ethyl cyanoacetate → Ethyl 2-cyano-3-(2,3-dichlorophenyl)propanoate

Participants

Reaction Steps

A mixture of ethyl 2-cyanoacetate (4.52 g, 40 mmol), 1-(bromomethyl)-2,3-dichlorobenzene (4.8 g, 20 mmol) and potassium carbonate (11.04 g, 80 mmol) in THF (80 mL) was under reflux for 30 h. After cooled to room temperature, the solvent was removed in vacuo and the resulting mixture was acidified with 2 N hydrochloric acid. The resulting solution was extracted with ethyl acetate (80 mL×3). The combined organic layers were washed with water and brine, dried over sodium sulphate, concentrated under reduced pressure. The residue was crystallized with MeOH to give the titled product (1.0 g, 18%) as a white solid. The mother liquor was concentrated in vacuo and the residue was purified by a silica gel chromatography eluted with PE/EA=20/1 to give the titled product (1.53 g, 33%) as a colorless oil; LC/MS: MS (ES+) m/e 272 (MH+); 1H NMR (300 MHz, CDCl3) δ ppm 1.31 (t, J=7.2 Hz, 3H), 3.24 (dd, J=9.6, 13.8 Hz, 1H), 3.56 (dd, J=6.3, 13.8 Hz, 1H), 3.90-3.96 (dd, J=6.3, 9.6 Hz, 1H), 4.28 (dq, J=0.9, 7.2 Hz, 2H), 7.18-7.29 (m, 2H), 7.44 (dd, J=1.8, 7.8 Hz, 1H).

Provenance & Evidence