Synthesis, X-ray crystallographic, spectroscopic and computational studies of aminothiazole derivatives

Aminothiazole organic compounds have diverse biological applications. Herein we report the synthesis of two aminothiazole derivatives: 4-(biphenyl-4-yl)thiazol-2-amine (1) and 4-(2',4'-difluorobipheny1-4-yl)thiazol-2-amine (2) via Suzuki-Miyaura cross coupling reaction. The chemical structures of 1 and 2 are confirmed using (HNMR)-H-1, (CNMR)-C-13, FT-IR, UV Vis and single crystal x-ray studies. The XRD study reveals that the both solid state structures (1) and (2) are diffused to form poly chain structures due to presence of intra molecular hydrogen bonding (H.B). Furthermore, these compounds were analysed by density functional theory (DFT) at M06-2X/6-311G(d,p), B3LYP/6-31G(d) B3LYP/6-31G(d,p) and B3LYP/6-311G(2d,p) level of theories to obtain optimized geometry, electronic and spectroscopic properties. DFT optimized geometry supports the experimental XRD parameters. Natural bond orbital (NBO) calculation predicted the hyper conjugative interaction and hydrogen bonding in all derivatives. The FTIR and thermodynamic studies also confirm the presence of hydrogen bonding network in the dimers which agrees well with the XRD results. Moreover, UV Vis analysis reveals that maximum excitations take place in 1 and 2 due to HOMO -> LUMO(98%) and HOMO -> LUMO(97%) respectively which show good agreement to experimental data. The first order hyperpolarizability of both molecules is remarkably greater than the value of urea. The global reactivity parameters which are obtained by frontier molecular orbitals disclose that the molecules might be bioactive. (C) 2016 Elsevier B.V. All rights reserved.