Phenyl isocyanate → HCID 59371583, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 4-nitrobutyrate (306 μL, 2.4 mmol) and 3-[[1-(tert-butoxycarbonyl)-2(S)-azetidinyl]methoxy]-5-ethynylpyridine (230 mg, 798 μmol) in dry benzene (8.0 mL) were added phenyl isocyanate (0.26 mL, 2.4 mmol) and triethylamine (0.22 mL, 1.6 mmol). The reaction mixture was stirred at 60° C. for 24 h, then diluted with water and stirred vigorously for 2 h. The mixture was extracted with CH2Cl2, and the organic phase was dried over MgSO4, filtered and concentrated in vacuo. The residue was purified by CC on SiO2 eluting with EtOAc/hexane 1:1 to give the isoxazole (283 mg, 85%). 1H NMR (CD3OD, 400 MHz) δ 8.50 (br s, 2H), 7.62 (s, 1H), 6.53 (s, 1H), 4.55 (br s, 1H), 4.40 (br s, 1H), 4.21 (dd, 1H, J=10.0, 2.4 Hz), 3.91 (t, 2H, J=7.2 Hz), 3.73 (s, 3H), 3.07 (t, 2H, J=7.2 Hz), 2.80 (t, 2H, J=7.2 Hz), 2.38 (m, 2H), 1.42 (s, 9H). 13C NMR (CDCl3, 100 MHz) δ 172.8, 167.1, 163.3, 156.3, 155.4, 139.8, 139.5, 124.3, 117.6, 100.9, 80.0, 69.0, 60.1, 52.0, 47.3, 32.1, 28.8, 21.7, 19.2.

Provenance & Evidence