反应详情

温度

-5 °C

5-Fluoro-2-{[(2E)-3-phenylprop-2-enyl]oxy}aniline (5-2, 2.19 g, 9.0 mmol) was suspended in a 1.2 N solution of HCl in 60% aq. AcOH (18 mL) and treated with ethyl-2-chloroacetoacetate (3.7 mL, 27 mmol). The mixture was cooled to −5° C. in a NaCl/ice bath and a 1.4 M solution of NaNO2 (12.6 mmol) in water was added dropwise under vigorous stirring. Upon completion of the addition, the mixture was adjusted to pH=4 with NaOAc and stirred to 25° C. for 2 h. The organics were extracted with CH2Cl2 (3×50 mL), dried (Na2SO4) and evaporated under reduced pressure. The crude was recrystallized from EtOAc/hexanes to give ethyl (2E)-chloro[(5-fluoro-2-{[(2E)-3-phenylprop-2-enyl]oxy}phenyl)hydrazono]ethanoate (5-3) as a brown solid. 1H NMR (300 MHz, CDCl3) δ 8.86 (s, 1H), 7.41 (d, J=7.3 Hz, 1H), 7.32 (m, 5H), 6.87 (dd, J=9.0, 4.7 Hz, 1H), 6.79 (d, J=15.9 Hz, 1H), 6.64 (app dt, J=8.3, 2.9 Hz, 1H), 6.40 (app dt, J=15.9, 5.5 Hz, 1H), 4.76 (d, J=5.2 Hz, 2H), 4.39 (q, J=7.0 Hz, 2H), 1.41 (t, J=7.0 Hz, 3H); MS (M+H+, C19H18ClFN2O3) 377.1 found 377.8 required.

1. additionUpon completion of the addition
2. extractionThe organics were extracted with CH2Cl2 (3×50 mL)
3. dry with materialdried (Na2SO4)
4. customevaporated under reduced pressure
5. customThe crude was recrystallized from EtOAc/hexanes