Synthesis, X-Ray, spectroscopic characterization (FT-IR, NMR, UV–Vis) and quantum chemical calculations of some substituted benzoylthiourea derivatives

A new series of substituted benzoylthiourea derivatives namely N-(4-methoxybenzoyl)-N`-(3-hydroxyphenyl)thiourea (1a), N-(3-methoxybenzoyl)-N`-(3-hydroxyphenyl) thiourea (2a), N-(3-nitrobenzoyl)-N`-(3-hydroxyphenyl)thiourea (3a) and N-(4-phenylbenzoyl)-N`-(3-hydroxy phenyl)thiourea (4a) bearing phenolic groups were efficiently synthesized from the condensation reaction of benzoylisothiocyanate with 3-aminophenol. The molecular structures of 1a-4a are elucidated by FT-IR, UV–Vis, ¹H and ¹³C NMR spectroscopic techniques. The four benzoylthiourea derivatives were obtained in crystalline forms by recrystallization in DMSO. X-ray chemical crystallographic study shows that 1a crystallizes in triclinic crystal system, while 2a-4a crystalize in monoclinic crystal system. The synthesized benzoylthiourea molecules adopt trans-cis configuration with respect to the positions of carbonoylbenzoyl and 3-hydroxyphenyl groups respectively, against the thiono C=S bonds across their C–N bonds. The corresponding predicted z-matrix coordinates and spectral data of 1a-4a were obtained using DFT and TD-DFT methods. The quantum chemical calculation have been carried out using three hybrid functionals B3LYP, B3P86 and PBE0 combined with 6–31++G(d,p) basis set. The solvent effects were taken into account implicitly using IEF-PCM model. The experimental Z-matrix coordinates and the spectral data of the tilted compounds are relatively well reproduced with good correlations coefficients.