反应详情

温度

24 °C

5-[4-(Trifluoromethyl)phenyl]1,3,4-oxadiazol-2-amine (10 g, 44 mmol) and potassium hydroxide (7.4 g, 0.132 mol) dissoved in abs. ethanol (300 ml) were heated at reflux for 3 h. After being cooled to 24° C., the solution was neutralized with acetic acid and concentrated by rotary evaporation. The residue was taken up in ethyl acetate and washed with water and brine. Recrystallization from acetonitrile/ether (2:1) gave 9 g (82%); mp 151-152° C.; IR(KBr, υ=cm−1) 2996, 1534, 1460, 1330, 1162, 1130, 1070; 1H NMR (300 MHz, DMSO-d6) δ 1.35 (3H, t, J=7.1 Hz), 4.38 (2H, q, J=7.0 Hz), 7.82 (2H, d, J=8.3 Hz), 8.10 (2H, d, J=8.1 Hz), 13.64 (1H, br. s); MS(DCl)m/z: 258 (MH+); Anal. calcd. for C11H10F3N3O: C, 51,37; H, 3.92; N, 16.34. Found: C, 51.40; H, 3.74; N, 16.28.

1. temperatureat reflux for 3 h
2. concentrationconcentrated by rotary evaporation
3. washwashed with water and brine
4. customRecrystallization from acetonitrile/ether (2:1)
5. customgave 9 g (82%)