Reaction Steps
To a solution of 3-(5-chlorofuran-2-yl)-4-phenyl-5-hydroxymethylisoxazole (350 mg, 1.273 mmoli) in Ac2O (5.2 ml), kept stirring at 0° C., is added Et3N (0.213 ml, 1.531 mmole). The mixture is brought to ambient temperature and kept stirring for 1.5 h. The reaction is blocked by adding ice and 10 ml of saturated solution of NaHCO3. The two phases are separated and the aqueous phase is extracted three times with methylene chloride. The combined organic extracts are dried over Na2SO4 and the solvent distilled in a vacuum. The residue subjected to column chromatography (silica gel, petroleum ether/ethyl acetate=9:1, and 8:2 after the elution of the first substance) gives 237 mg of oily product with a yield of 60%. FT-IR (neat): 3132, 3053, 2921, 1751, 1636, 1517, 1432, 1412, 1372, 1359, 1226, 1127, 1048, 1018, 985, 939, 903, 790, 777, 704 cm−1. 1H NMR (400 MHz, CDCl3, δ): 7.44-7.42 (m, 3H, aromatic protons); 7.30-7.28 (m, 2H, aromatic protons); 6.24 (d, J=3.6 Hz, 1H, furyl proton); 6.11 (d, J=3.6 Hz, 1H, furyl proton); 5.07 (s, 2H, CH2); 2.02 (s, 3H, CH3).13C NMR (75 MHz, CDCl3, δ): 170.3, 163.5, 152.7, 143.1, 139.0, 130.2, 129.2, 129.2, 128.2, 118.2, 114.4, 108.2, 55.4, 20.7. GC-MS (70 eV) m/z (rel.int.): 319 [M(37Cl)+, 33], 317 [M(35Cl)+, 90], 277 (18), 276 (10), 275 (49), 240 (18), 238 (10), 217 (23), 216 (11), 213 (17), 212 (100), 211 (32), 190 (11), 188 (27), 182 (11), 154 (20), 153 (26), 152 (21), 129 (15), 127 (19), 91 (12), 89 (26), 73 (11), 43 (30). Anal. Calc. for C16H12ClNO3: C, 64.48; H, 3.81; N, 4.41. Found: C, 64.46; H, 3.82; N, 4.46.
