Synthesis, Spectroscopic Characterization and X-ray Structure Analysis of 6-(2,5-Dichlorothiophen-3-yl)-3,4-dihydro-4-(4-methoxyphenyl)pyrimidine-2(1H)-thione

Abstract

The title compound was prepared by the condensation of (E)-1-(2,5-dichlorothiophen-3-yl)-3-(4-methoxy)prop-2-en-1-one and thiourea in the presence of KOH. In the title compound, C34H28Cl16N4O2S4, the asymmetric unit consists of two independent molecules and four independent chloroform molecules. The heterocyclic pyrimidine-2(1H)-thione rings adopt a flattened boat conformation. The methoxyphenyl rings are perpendicular to the pyrimidine-2(1H)-thione rings with dihedral angles of 81.20 and 79.85° in both independent molecules. The dichlorothiophene rings are twisted compared to the pyrimidine-2(1H)-thione rings with dihedral angles of 40.59 and 39.36° in the independent molecules. The methoxyphenyl group has an axial orientation. Intermolecular C–H···S, C–H···O, C–H··· π vertex-to-face intermolecular interactions between chloroform C–H groups and the center of the phenyl rings and extensive Cl···Cl intermolecular interactions are found in the crystal structure. All interactions consolidate a three dimensional network. The molecular structure was further analyzed using spectroscopic methods. Mass ESI-HMRS measurements were performed. The HRESIMS analysis revealed the molecular formula, C15H12Cl2N2OS2, with [M+H]+ and [M+H+2]+ and [M+H+4]+ isotopic clusters characteristic for a dichlorinated compound. The compound was also thoroughly characterized by 1H, 13C, NMR spectra and 2D NMR spectra (COSY, HSQC and HMBC). Synthesis, characterization, molecular, crystal structure and crystal supramolecularity of the three dimensional network structure of 6-(2,5-dichlorothiophen-3-yl)-3,4-dihydro-4-(4-methoxyphenyl)pyrimidine-2(1H)-thione are reported.