2-溴-3-(溴甲基)吡啶是重要的有机合成中间体,广泛应用于医药、农药等领域的有机合成反应中。
医药; 农药
合成路线 1(1. 合成:94446-97-6)
产率:41%
合成条件:With N-Bromosuccinimide; 2,2'-azobis(isobutyronitrile) In benzene at 40℃; for 8 h; UV-irradiation; Inert atmosphere
实验步骤:该中间体是通过基于Rebek,J.,et al。,I Am。中公开的修改方法产生的。化学。 Soc。,107,7487(1985))。将具有搅拌棒的三颈圆底烧瓶火焰干燥,在真空下冷却并用N 2吹扫。向烧瓶中加入2-溴-3-甲基哌啶(5.2mL,29.1mmol),N-溴代琥珀酰亚胺(5.5g,32.0mmol)和脱气的苯(126mL)。将烧瓶配备冷凝器,加热至40℃并分几批加入AIBN(0.24g,1.5mmol)。当在40℃下搅拌时,使用太阳灯照射反应。使用TLC和HPLC监测反应,并在吡啶试剂80%转化后停止(约8小时)。将反应混合物在减压下浓缩,然后再溶于4:1 DCM / EtOAc(120mL)中,并用50mL饱和NaHCO 3(aq)溶液,水和NaCl(aq)的饱和溶液萃取一次。有机相用无水硫酸钠干燥,过滤并浓缩。静置后,残余物不能完全重新溶解在DCM中,过滤所得悬浮液以除去不溶性固体。将滤液浓缩至接近干燥,并通过正相快速色谱法(EtOAc /己烷)纯化残余物,得到标题化合物I-i(3.0g,11.9mmol,41%),为黄色固体。 1 H NMR(400MHz,CDCl 3)δ8.33(1H,dd,J5,2Hz),7.78(1H,dd,J7,2Hz),7.28(1H,dd,J = 5.4Hz),4.57( 2H,s),MS(LC / MS)m / z观察值249.97,预计值249.89 [M + Hj]
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