Ethyl 2-butynoate → HCID 71254826, compound

Participants

Reaction Conditions

Reaction Steps

Ethyl 3-(3-chloro-2-fluorophenyl)-4-methylisoxazole-5-carboxylate: Ethyl but-2-ynoate (0.725 ml, 6.22 mmol) and Intermediate 46A (0.36 g, 2.074 mmol) were dissolved in acetonitrile (10.37 mL). Magtrieve (1.742 g, 20.74 mmol) was added and the reaction mixture was stirred in a sealed tube at 80° C. After 2 h, the reaction was cooled to rt and then it was filtered through CELITE®, rinsing with EtOAc. The filtrate was concentrated and purified by reverse phase HPLC to afford the desired product (0.009 g, 2% yield) as a white solid. MS(ESI) m/z: 284.0 (M+H)+. 1H NMR (500 MHz, MeOD) δ 7.70 (ddd, J=8.0, 7.2, 1.7 Hz, 1H), 7.49 (ddd, J=7.8, 6.3, 1.7 Hz, 1H), 7.35 (td, J=7.8, 1.1 Hz, 1H), 4.46 (q, J=7.2 Hz, 2H), 2.25 (d, J=1.9 Hz, 3H), 1.42 (t, J=7.2 Hz, 3H) ppm. The other regioisomer, ethyl 3-(3-chloro-2-fluorophenyl)-5-methylisoxazole-4-carboxylate (0.083 g, 14%) was also obtained as a colorless oil. MS(ESI) m/z: 284.0 (M+H)+.

Provenance & Evidence