[CH3:1][Si](C=[N+]=[N-])(C)C.[CH3:8][O:9][C:10]1[CH:15]=[CH:14][C:13]([C:16]2[CH:20]=[C:19]([C:21]([OH:23])=[O:22])[O:18][N:17]=2)=[CH:12][CH:11]=1>CCOCC.CO.C(Cl)Cl>[CH3:8][O:9][C:10]1[CH:11]=[CH:12][C:13]([C:16]2[CH:20]=[C:19]([C:21]([O:23][CH3:1])=[O:22])[O:18][N:17]=2)=[CH:14][CH:15]=1Trimethylsilyldiazomethane (3.50 mL of a 2 M soln in Et2O, 7.01 mmol) was added to a stirred solution of 3-(4-methoxyphenyl)-5-isoxazolecarboxylic acid (0.96 g, 4.38 mmol) in dry MeOH (4.38 mL) and dry CH2Cl2 (39 mL) at 25° C. under N2. The reaction was stirred at 25° C. for 2 h. The reaction mixture was concentrated in vacuo to afford methyl 3-(4-methoxyphenyl)isoxazole-5-carboxylate, as a colorless solid. LCMS calc.=234.08. found=233.98 (M+H)+. 1H NMR (600 MHz, CDCl3): δ 7.76 (d, J=8.4 Hz, 2H); 7.19 (s, 1H); 6.98 (d, J=8.4 Hz, 2H); 3.99 (s, 3H); 3.86 (s, 3H).
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