Ethyl Methacrylate → Ethyl 3-(5-bromo-2-pyridyl)-5-methyl-4H-isoxazole-5-carboxylate

Participants

Reaction Steps

To the solution of 5-bromo-N-hydroxy-pyridine-2-carboximidoyl chloride (0.6 g, 2.56 mmol) in EtOAc (15 mL) was added ethyl methacrylate (1.5 mL, 13.33 mmol) at 0° C. The mixture was stirred at the same temperature for 10 min followed by addition of triethyl amine (0.35 mL, 2.82 mmol) then stirred at 0° C. for 1 h. After completion (by TLC), the residue was poured into 100 mL of ice-cold water followed by extraction with EtOAc (3×100 mL). The combined organics were washed with brine, dried over anhydrous Na2SO4, filtered and evaporated under reduced pressure. The crude residue was purified over 100-200 M silica-gel using 5.0% EtOAc:hexane to obtain a white solid product (0.70 g, 88% yield). 1H NMR (DMSO-d6): δ 1.19 (t, J=7.20 Hz, 3H), 1.60 (s, 3H), 3.41 (m, 1H), 3.86 (m, 1H), 4.16 (q, J=7.20 Hz, 2H), 7.87 (d, J=8.4 Hz, 1H), 8.14 (d, J=2.4 Hz, 1H) and 8.79 (s, 1H).

Provenance & Evidence