Thieno[2,3-b][1] benzothiophen and thieno[3,2-b][1]benzothiophen. Part I. Preparation
作者:N. B. Chapman、C. G. Hughes、R. M. Scrowston
DOI:10.1039/j39700002431
日期:——
cyclised with polyphosphoric acid to give thieno[2,3-b or 3,2-b][1] benzothiophen derivatives. Thieno[2,3-b][1]benzothiophen-2-carboxylic acid, its 5-bromo-derivative, and thieno[3,2-b][1]benzothiophen-2-carboxylic acid were prepared by cyclisation of the appropriate β-(3- or 2-benzo[b]thienyl)-α-mercaptoacrylic acid with iodine in either tetrahydrofuran or nitrobenzene. The formation of thieno[2,3-b or
通过用硫处理适当的2-苯并[ b ]噻吩基-锂衍生物,制得苯并[ b ]噻吩-2-硫醇及其5-和7-氯衍生物。苯并[ b ]噻吩及其5-溴和7-氯衍生物在3-位被磺化。将所得的磺酸转化为磺酰氯,将其还原(LiAlH 4)为相应的3-硫醇。这样制得的2-和3-硫醇易于与氯乙醛二乙缩醛,氯丙酮或3-氯丁-2--2-酮缩合,产物用多磷酸环化得到噻吩并[2,3- b或3,2- b]。 ] [1]苯并噻吩衍生物。锡诺[2,3- b] [1]苯并噻吩-2-羧酸,其5-溴衍生物和噻吩并[3,2- b ] [1]苯并噻吩-2-羧酸是通过将适当的β-(3-或2)环合制备的-苯并[ b ]噻吩基)-α-巯基丙烯酸与碘的混合物在四氢呋喃或硝基苯中。噻吩并[2,3- b或3,2- b ] [1]苯并噻吩SS-二氧化物的形成可能分别涉及与苯环相邻的硫原子的氧化。