Toluene → ethyl 6-chloro-8-(4-chlorophenyl)-2-(trifluoromethyl)-2H-1-benzopyran-3-carboxylate

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Reaction Steps

Ethyl 6-chloro-8-iodo-2-(trifluoromethyl)-2H-1-benzopyran-3-carboxylate (Example 73, Step 2) (1.3 g, 3.02 mmol), potassium carbonate (1.25 g, 9.06 mmol), 4-chorophenylboronic acid (0.52 g, 3.33 mmol), and tetrakis(triphenylphosphine)palladium(0) (0.174 g, 0.151 mmol) were added to toluene (30 mL) and the resulting solution was heated to reflux for 18 hours. After cooling to room temperature the reaction mixture was poured into ethyl acetate (50 mL). It was washed with 1 N HCl (2×25 mL), saturated aqueous sodium bicarbonate (2×25 mL), and water (2×25 mL). The organic phase was dried over MgSO4, filtered, and concentrated in vacuo to yield a brown oil. The crude material was purified by flash chromatography using 1% ethyl acetate in hexane yielding a white solid. Recrystallization from hexane afforded the ester as a white solid (0.79 g, 64%): mp 114.2–115.9° C. 1H NMR (CDCl3/300 MHz) 7.69 (s, 1H), 7.41 (s, 4H), 7.30 (d, 1H, J=2.4 Hz), 7.22 (d, 1H, J=2.6 Hz), 5.70 (q, 1H, J=6.9 Hz), 4.37–4.29 (m, 2H), 1.35 (t, 3H, J=7.1 Hz). ESLRMS m/z 434 (M+NH4+). FABHRMS m/z 434.0574 (M+NH4+, Calc'd. 434.0538). Anal. Calc'd. for C19H13Cl2F3O3: C, 54.70; H, 3.14; Cl, 17.00. Found: C, 54.79; H, 3.18; Cl, 16.65.

Provenance & Evidence