SYNTHESIS AND SOME TRANSFORMATIONS OF BENZOTHIOPHENE DERIVATIVES

Article abstract of DOI:10.1007/BF00506608

A number of 3-chloro-2-chlorocarbonylbenzothiophenes with alkyl substituents in various positions of the benzene ring were synthesized by arylation of acrylic acid with the corresponding alkyl-substituted iodobenzenes under the influence of catalytic amounts of palladium acetate and subsequent oxidation of the resulting arylacrylic acids with thionyl chloride.Replacement of the pyridine added in the oxidation reaction by triethylbenzylammonium chloride led to substantial increases in the yields of the desired products.The possibility of conversionof the resulting benzothiophene derivatives to thiophene ring-unsubstituted benzothiophenes was shown in the case of 3-chloro-2-chlorocarbonylbenzothiophene as a result of successive saponification of the 2-chlorocarbonyl group, decarboxylation, and dechlorination.