Cyanoacetic acid → HCID 69607388, compound

Participants

Reaction Steps

To a stirred suspension of PCl5 (0.74 g, 3.5 mmol) in CH2Cl2 (10 mL) was added a solution of cyanoacetic acid (0.3 g, 3.5 mmol) in CH2Cl2 (5 mL) and DMF (1 mL) dropwise via syringe at room temperature and the reaction mixture was heated at reflux for 1 hour. The reaction was cooled to room temperature and a solution of 2-Amino-4-(3,5-dimethyl-phenyl)-thiophene-3-carboxylic acid ethyl ester (0.78 g, 2.8 mmol) in CH2Cl2 (5 mL) was added via canula over 5 minutes. The reaction was then heated at reflux for 2.5 h, cooled to 0° C. and quenched by slow addition of sat. aq. Na2CO3 (10 mL) until basic (pH 9–10). The mixture was extracted with ethyl acetate (3×30 mL) and the combined organic layers were washed with water (25 mL), brine (15 mL), dried (Na2SO4), filtered and concentrated under reduced pressure to provide the title compound as a yellow solid. MS (ESI) m/e 341.0 (M−H); 1H NMR (300 MHz, CDCl3): δ ppm 12.02 (s, 1H), 7.26 (s, 1H), 6.97 (s, 1H), 6.91 (s, 2H), 6.67 (s, 1H), 4.15 (q, 4H, J=7.12), 3.68 (s, 2H), 2.33 (s, 6H), 0.98 (t, 3H, J=7.12).

Provenance & Evidence