Triethylamine → ethyl 6-iodo-2-trifluoromethyl-2H-1-benzopyran-3-carboxylate

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Reaction Conditions

Reaction Steps

A mixture of 5-iodosalicylaldehyde (16.2 g, 65.3 mmol), ethyl 4,4,4-trifluorocrotonate (22.4 g, 133 mmol) and triethylamine (50 ml, 395 mmol)were combined, stirred at 70° C. for 8 h and then heated at reflux for 48 h. The solution was poured into ethyl acetate (300 mL) and washed with 1N hydrochloric acid (3×200 mL). The aqueous layers were combined and extracted with ethyl acetate (1×100 mL). The combined ethyl acetate extracts were washed with saturated ammonium chloride (2×200 mL), dried over magnesium sulfate and concentrated in vacuo yielding a dark red oil. This oil was purified by flash chromatography using ethyl acetate-hexanes (3:7) yielding a red oil. Crystallization of this oil from hexanes yielded the title compound as light red crystals (8.3 g, 31%): mp 105–106° C. 1H NMR (CDCl3/300 MHz) 7.63 (s, 1H), 7.58 (dd, 2H, J=8.6, J=2.1 Hz, 7.54 (d, 1H, J=2.1 Hz), 6.77 (d, 1H, J=8.6 Hz), 5.70 (q, 1H, J=6.7 Hz), 4.20–4.38 (m 2H), 1.35 (t, 3H, J=7.2 Hz). ESHRMS 415.9926 (M+NH4+ Calc'd 396.9746)

Provenance & Evidence