[C:1]1([C:7]2[O:11][N:10]=[C:9]([NH2:12])[CH:8]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[C:13](=[O:16])([O-])[O-:14].[K+].[K+]>O1CCCC1>[C:1]1([C:7]2[O:11][N:10]=[C:9]([NH:12][C:13](=[O:16])[O:14][C:1]3[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=3)[CH:8]=2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=15-Phenylisoxazol-3-amine (428 mg, 2.67 mmol) in tetrahydrofuran (4.8 mL) was treated with potassium carbonate (481 mg, 3.47 mmol) and phenyl choloroformate (0.67 mL, 5.3 mmol). The reaction mixture was stirred at room temperature overnight. The mixture was filtered through a celite pad, washed with ethyl acetate and concentrated to dryness. The residue was taken into chloroform, washed with brine, and the organics dried (MgSO4) and concentrated. The residue was purified by silica gel chromatography (hexane/ethyl acetate 8:2) to give phenyl 5-phenylisoxazol-3-ylcarbamate (599 mg, 80%) as a white solid. 1H NMR (300 MHz, CDCl3) δ 7.92 (bs, 1H), 7.78 (d, 2H), 7.45 (m, 6H), 7.26 (m, 2H), 7.12 (s, 1H); LC-MS (ESI) m/z 281 (M+H)+.
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