反应详情

Ethylenediamine (6.23 mL, 93.1 mmol) was added dropwise to a stirred solution of AlMe3/Tol (58 mL, 2M), so that the temperature did not exceed −20° C. The reaction mixture was stirred at room temperature for 10 min, then to the mixture was added dropwise a solution of the compound 27 (4.5 g, 23.3 mmol) in Toluene (290 mL). The reaction mixture was stirred at 120° C. for overnight. After cooling, the solution was treated dropwise with water, diluted DCM and CH3OH and filtered with over MgSO4. The filtrate was concentrated and purified with silica gel column chromatography (EtOAc:CH3OH:TEA=3:1:0.2) to give the compound 55 (4.5 g, 96%) as a light yellow oil. 1H NMR (400 MHz, CDCl3) δ6.96 (d, 2H, J=8.3 Hz), 6.62 (d, 2H, J=8.3 Hz), 3.56 (s, 4H), 2.55 (t, 2H, J=7.4 Hz), 2.23 (d, 2H, J=7.4 Hz), 1.84-1.94 (m, 2H).

1. customdid not exceed −20° C
2. stirringThe reaction mixture was stirred at 120° C. for overnight
3. temperatureAfter cooling
4. filtrationfiltered with over MgSO4
5. concentrationThe filtrate was concentrated
6. custompurified with silica gel column chromatography (EtOAc:CH3OH:TEA=3:1:0.2)