Solvent-Free Synthesis and Spectral Linearity of Some (E)-2-(substituted benzylideneamino)-N-(3-chloro-4-fluorophenyl)-hexahydro-2<i>H</i>-cyclopenta[b]thiophene-3-carboxamides

Abstract

Some (E)-2-(substituted benzylideneamino)-N-(3-chloro-4-fluorophenyl)-hexahydro-2H-cyclopenta[b]thiophene-3-carboxamide derivatives have been synthesized by SiO2:H3PO4 catalyzed solvent-free condensation of 2-amino-N-(3-chloro-4-fluorophenyl)-hexahydro-2H-cyclopenta [b]thiophene-3-carboxamide and various substituted benzaldehydes in microwave irradiation. The yield of the imine-carboximido derivatives has been found to be more than 85 %. The purity of all imine-carboximido derivatives has been checked using their physical constants and spectral data. The spectral data of the imine-carboximido derivatives such as infrared ν (cm-1) of CO, NH, C-N, C-Cl, C-F, C=N, and the NMR chemical shifts (δ, ppm) of NH, CH, CO and C=N have been correlated with Hammett substituent constants, F and R parameters. From the results of statistical analysis, the effects of substituent on the above spectral group absorptions have been discussed.