Acetic Acid → 2-Cyano-3-(5-iodo-4-methyl-thiophen-2-yl)-but-2-enoic acid ethyl ester

참여 물질

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반응 단계

Acetic acid (9.4 ml) was placed in a flask at rt and HMDS (3.0 ml, 14.1 mmol) was added dropwise. After the exotherm subsided, 1-(5-Iodo-4-methyl-thiophen-2-yl)-ethanone (2.5 g, 9.4 mmol) was added as a solid followed by ethyl cyanoacetate (2.0 ml, 18.8 mmol). The reaction was stirred at 80° C. for 8 h, cooled to rt and concentrated by rotary evaporation to give a brown residue. The residue was taken up in EtOAc, washed with NaHCO3 (aq, sat.) and then with H2O. The organics were dried (NaSO4), filtered and concentrated to give a brown solid. The solid was triturated with EtOH and filtered to give 2-Cyano-3-(5-iodo-4-methyl-thiophen-2-yl)-but-2-enoic acid ethyl ester (2.0 g, 5.5 mmol, 58%) as a light yellow solid. MS (ESI) m/z 362.0 (M+H+); 1H NMR (300 MHz, DMSO-d6) δ ppm 1.27 (t, 1H) 2.21 (s, 1H) 2.66 (s, 1H) 4.26 (q, 1H) 7.67 (s, 4H).

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