Diethyl Ether → HCID 21883586, compound

Participants

Reaction Steps

In a 100 mL round bottomed flask under N2, ethyl 8-bromo-6-chloro-2-trifluoromethyl-2H-benzopyran-3-carboxylate (Example 74, Step 1)(2.21 g, 5.73 mmol) was dissolved in toluene (30 mL of anhydrous reagent). Tetrakis (triphenylphosphine)palladium(0) (0.132 g, 0.115 mmol) was added, followed by tributylethyenylstannane (2.0 g, 6.31 mmol). The resulting solution was heated to reflux for 5 hours. The reaction mixture was allowed to cool to room temperature, was poured into 50 mL of 20% ammonium fluoride solution and stirred for one hour. Diethyl ether (100 mL) was added and the mixture was washed with water (2×50 mL). The organic phase was dried over MgSO4, filtered, and evaporated to yield a yellow oil. The crude material was purified by flash chromatography (0.5% ethyl acetate in hexanes) to afford the ester as a yellow solid (0.86 g, 45%): mp 75.9–77.2° C. 1H NMR (CDCl3/300 MHz) 7.64 (s, 1H), 7.45 (d, 1H, J=2.5 Hz), 7.12 (d, 1H, J=2.6 Hz), 6.92 (dd, 1H, J=17.7 Hz, 11.3 Hz), 5.81 (d, 1H, J=17.7 Hz), 5.76 (q, 1H, J=6.8 Hz), 5.41 (d, 2H, J=11.1 Hz), 4.36–4.29 (m, 2H), 1.36 (t, 3H, J=7.3 Hz). FABLRMS m/z 350.1 (M+NH4+). ESHRMS m/z 350.0796 (M+NH4+, Calc'd. 350.0771). Anal. Calc'd. for C15H12ClF3O3+4.07% H2O: C, 51.95; H, 3.94. Found: C, 51.67; H, 3.69.

Provenance & Evidence