Triethylamine → ethyl 6-chloro-8-iodo-2-(trifluoromethyl)-2H-chromene-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

5-Chloro-3-iodosalicylaldehyde (20 g, 70.8 mmol), ethyl 4,4,4-trifluorocrotonate (17.85 g, 106 mmol), and triethylamine (14.33 g, 142 mmol) were dissolved in DMSO (200 mL). The reaction mixture was stirred at 90° C. for three days. The reaction mixture was poured into ethyl acetate (800 mL). It was extracted with 10% HCl (2×200 mL), saturated aqueous NaHCO3 (2×200 mL), and water (2×200 mL). The ethyl acetate phase was dried over MgSO4, filtered and evaporated to yield a brown solid. It was then run through a plug of silica with ethyl acetate-hexane (1:20). The solvent was evaporated to give a yellow solid, that was recrystallized in hexane to afford the ester as a white solid (19.61 g, 64%): mp 92.1–93.9° C. 1H NMR (CDCl3/300 MHz) 7.71 (d, 1H, J=2.2 Hz), 7.56 (s, 1H), 7.20 (d, 1H, J=2.2 Hz), 5.81 (q, 1H, J=6.7 Hz), 4.37–4.29 (m, 2H), 1.35 (t, 3H, J=7.2 Hz). FABLRMS m/z 431.9 (M−H). EIHRMS m/z 431.9269 (M−H, Calc'd. 431.9237).

Provenance & Evidence