[Cl:1][C:2]1[CH:3]=[C:4]([C:8]2[N:9]=[C:10]([C:13]3[CH:18]=[CH:17][C:16]([N+:19]([O-])=O)=[CH:15][CH:14]=3)[O:11][CH:12]=2)[CH:5]=[CH:6][CH:7]=1.O.O.[Sn](Cl)Cl>CO.C(OCC)(=O)C>[Cl:1][C:2]1[CH:3]=[C:4]([C:8]2[N:9]=[C:10]([C:13]3[CH:18]=[CH:17][C:16]([NH2:19])=[CH:15][CH:14]=3)[O:11][CH:12]=2)[CH:5]=[CH:6][CH:7]=1under an N2 atmosphere, was 4-(3-chlorophenyl)-2-(4-nitrophenyl)oxazole (2.65 g, 8.81 mmol) suspended in methanol (20.0 mL) and tin(II) chloride dihydrate (7.95 g, 35.3 mmol) was added. The reaction was stirred at room temperature for ca. 72 h. LC-MS showed the reaction was not complete. The reaction was heated to 60° C. for 5 hours. The reaction was then diluted with ethyl acetate and washed with 0.1N HCl, followed by 5% NaHCO3 and brine. The organic layer was then dried (Na2SO4), filtered and concentrated in vacuo. The crude residue was purified by chromatography on silica gel, eluting with 20% to 40% ethyl acetate in hexanes. The resulting solid was triturated with ethyl acetate/hexanes and the resulting solid was collected by filtration to afford 4-(4-(3-chlorophenyl)oxazol-2-yl)benzenamine (0.898 g, 37.6% yield). ESI m/z=271.0 (M+H+).
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