Synthesis, Spectroscopic Characterization and X-ray Structure Analysis of 6-(2,5-Dichlorothiophen-3-yl)-2-methoxy-4-(4-methoxyphenyl)pyridine-3-carbonitrile

Abstract

The title compound was prepared by the condensation of an equimolar mixture of 1-(2,5-dichlorothiophen-3-yl)-3-(4-methoxyphenyl)prop-2-en-1-one, malononitrile and sodium hydroxide. The molecular structure was fully characterized using different spectroscopic methods. Mass ESI–HRMS measurements were performed. The HRESIMS analysis revealed the molecular formula, C₁₈H₁₂Cl₂N₂O₂SNa, with [M + Na]⁺ and [M + Na + 2]⁺ and [M + Na + 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). The molecular structure was confirmed by X-ray single crystal analysis. The new compound crystallizes in the orthorhombic, Pbcn space group with unit cell dimensions: a = 31.901(7) Å, b = 15.412(4) Å, c = 7.3655(14) Å, V = 3621.3(13) ų and Z = 8. In the title compound, the central pyridine ring carries four substituents, a thiophene ring, a methoxyphenyl ring, a carbonitrile group and a methoxy group. The dihedral angles between the planes of the pyridine ring, the thiophene ring and the methoxyphenyl ring are 36.66 and 40.18°, respectively. Intermolecular C–H···O/N, π···π and anion···π [Cl···π] interactions are found in the crystal structure. All interactions consolidate a three dimensional network.

Graphical Abstract

Synthesis, characterization, crystal, molecular structure, and crystal supramolecularity of 6-(2,5-dichlorothiophen-3-yl)-2-methoxy-4-(4-methoxyphenyl)pyridine-3-carbonitrile are reported.