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

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).

1. stirringthen stirred at 0° C. for 1 h
2. extractionfollowed by extraction with EtOAc (3×100 mL)
3. washThe combined organics were washed with brine
4. dry with materialdried over anhydrous Na2SO4
5. filtrationfiltered
6. customevaporated under reduced pressure
7. customThe crude residue was purified over 100-200 M silica-gel

ORD record

ord-a447e01b1987490a9c31e3b4dae3aa17

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09181234B2