Sodium hydride → (E)-3-{4-[1-(4-trifluoromethoxyphenyl)-1H-[1,2,4]triazol-3-yl]phenyl}acrylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

Sodium hydride (NaH, 60% suspension in mineral oil; 440 milligrams (mg), 11.0 millimoles (mmol)) was suspended in THF (20 milliliters (mL)), and the mixture was cooled to 0° C. t-Butyl diethylphosphonoacetate (2.57 mL; 11.0 mmol) was added over 2 minutes (min). The mixture was stirred at 0° C. for another 15 min, during which time the grey slurry turned clear within 5 min. 4-[1-(4-Trifluoromethoxyphenyl)-1H-[1,2,4]triazol-3-yl]-benzaldehyde (3.04 grams (g); 9.13 mmol) was suspended in THF (20 mL) and then added dropwise via cannula to the solution above. The mixture was then warmed to 25° C., poured into saturated (satd) aqueous (aq) ammonium chloride (NH4Cl; 200 mL), and extracted with 50% ethyl acetate (EtOAc)/hexanes (3×100 mL). The combined organic extracts were then dried over sodium sulfate (Na2SO4) and concentrated in vacuo. The yellow solid residue was dissolved in dichloromethane (CH2Cl2; 10 mL) and rapidly stirred as hexanes (100 mL) was added dropwise over 30 min. The light yellow crystals were collected on a Büchner funnel and dried in vacuo to afford the title compound ((2.93 g, 74%). The filtrate was concentrated in vacuo and purified by chromatography on silica gel (gradient elution with 15% to 40% to 80% EtOAc in hexanes) to afford additional product (0.215 g, 5%): mp 167-169° C.; 1H NMR (400 MHz, CDCl3) δ 8.58 (s, 1H), 8.20 (d, J=8.3 Hz, 2H), 7.80 (d, J=8.9 Hz, 2H), 7.63 (d, J=15.8 Hz, 1H), 7.62 (d, J=8.5 Hz, 2H), 7.39 (d, J=8.6 Hz, 2H), 6.44 (d, J=16.0 Hz, 1H), 1.54 (s, 9H); HRMS-ESI (m/z) [M]+ calcd for C22H20F3N3O3, 431.146; found, 431.1457.

Provenance & Evidence