2-Amino-4-(trifluoromethyl)phenol → 2-ChloroMethyl-5-trifluoroMethyl-benzooxazole
反応式
[Cl:1][CH2:2][C:3]([O:10][CH2:11][CH3:12])(OCC)OCC.[NH2:13][C:14]1[CH:19]=[C:18]([C:20]([F:23])([F:22])[F:21])[CH:17]=CC=1O>C(O)(=O)C>[Cl:1][CH2:2][C:3]1[O:10][C:11]2[CH:12]=[CH:17][C:18]([C:20]([F:23])([F:22])[F:21])=[CH:19][C:14]=2[N:13]=1参加物
4
反応条件
- 温度
- 120 °C
実験手順
2-Chloro-1,1,1-triethoxyethane (410 μL, 2.15 mmol) was added to a suspension of 2-amino-4-trifluoromethylphenol (370 mg, 1.79 mmol) in acetic acid (7 mL); during the addition the solution began to clear. The solution was heated at 120° C. (external temperature). After three hours the reaction mixture was cooled and the volatiles were removed under reduced pressure. Purification by silica gel chromatography, eluting with a gradient of 0 to 10% ethyl acetate in heptanes, gave 2-chloromethyl-5-trifluoromethyl-benzoxazole as a yellow oil (324 mg, 77%). (CI, m/z): [M+H]+ 236; 1H NMR (CDCl3): δ 8.05 (s, 1H), 7.66-7.73 (m, 2H), 4.79 (s, 2H); 19F NMR (376 MHz, CDCl3): δ ppm −61.26 (s, 3F).