5-氨基噻唑-4-甲酸乙酯作为医药中间体,用于相关药物合成。
医药
合成路线 1(1. 合成:18903-18-9)
产率:60%
合成条件:With Lawessons reagent In toluene at 70℃;
实验步骤:化合物16c的合成:5-氨基噻唑-4-羧酸乙酯:将化合物16b(9.0g,58mmol)悬浮在甲苯(200ml)中。一次性加入Lawesson试剂(23.0g,58mmol,1当量)。将获得的黄色悬浮液在70℃和N 2气氛下搅拌过夜。将反应混合物冷却至0℃,从烧瓶底部的胶状物质中倾析出甲苯层,并用1N.Aq。 HCl(6x50 ml)。将胶状物质溶于MeOH(150ml)中并减压浓缩。将残余物(棕色油状物)悬浮在TBME(300ml)中并用1N.Aq。 HCl(1×300ml,2×100ml)。将合并的含水部分用2N.Aq。碱化。 NaOH(460ml)并用EtOAc(1×300ml,2×200ml和1×100ml)萃取。将合并的有机层干燥(Na 2 SO 4),过滤并减压浓缩,得到粗标题化合物(7g)。通过柱色谱(二氧化硅,庚烷-EtOAc,1/1)纯化粗物质,得到化合物16c(6g,35mmol,60%),为棕色固体。 1H-NMR(300MHz,CDCl3)? 7.89(s,1H),6.04(bs,2H),4.42(q,2H,J = 7Hz),1.43(t,3H,J = 7Hz)。
参考文献:
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