When hydrogen bond tailors molecular packing in non-anisometric molecules. The case study of N-alkyl 1,3-diphenyl-4,5-dihydro-1H-pyrazole-5-carboximidamides

In this paper, we report the synthesis of novel liquid crystals (LCs) based on 5-membered pyrazoline heterocycle. The synthesis of pyrazoline derivative was carried out by 3 + 2] 1,3-dipolar cycloaddition reaction of benzaldehyde phenyl hydrazone (1) with acrylonitrile, mediated by chloramine-T as the oxidising agent, followed by addition of hydroxylamine hydrochloride, and subsequently alkylated with various alkyl chains to afforded the title compounds. The LCs properties were investigated using differential scanning calorimetry and polarising optical microscopy. For title compounds with longer alkyl chains, monotropic columnar hexagonal mesophase was characterised by XRD analysis. The mesophase-formation was driven by intermolecular hydrogen bonds despite their non-discoid molecular structure. GRAPHICS]

Synthesis of 5-{[(1Hbenzo[d]imidazol-2-yl)sulfonyl]methyl}-3-phenyl-4,5-dihydroisoxazole derivatives, invitro antibacterial and antioxidant studies along with their insilico analyses

Synthesis of a series of novel sulfone derivatives 6(a-u) possessing benzimidazoles and isoxazoline rings tailored in a single molecule 5(a-u) was done by reactions using 5-(bromomethyl)-3-phenyl-4,5-dihydroisoxazoles 3(a-u) and 5-{[(1H-benzo[d]imidazol-2-yl)thio]methyl}-3-phenyl-4,5-dihydroisoxazoles 4(a-u) molecules. The chemical structures of all the newly synthesized compounds were established by IR, 1HNMR, 13CNMR and LCMS spectral data. The biological characteristics of the novel sulfone compounds, such as their antioxidant and antibacterial activity, were evaluated. Among the synthesized sulfones derivatives, compounds 6 g, 6b, and 6e demonstrated outstanding antibacterial activity while compounds 6b, 6c, 6i, 6j, and 6 k demonstrated higher antioxidant activity. Further insilico absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies of synthesized sulfones were studied which exhibited excellent intestinal absorption which is more than 80 %, and relatively moderate toxicity. Molecular docking studies confirmed the antibacterial and antioxidant potential which is comparable with the standard

Small molecule based five-membered heterocycles: A view of liquid crystalline properties beyond the biological applications

Liquid crystal (LC) is an intermediate phase of matter with the physical attributes of liquid, and a high-level of orientational order of solids. This property of LCs has been widely utilized for the development of LC displays and other industrial applications. The research in the past few decades shows the substantial increase in the exploring of applications of five-membered liquid crystalline heterocydes in photovoltaic devices, organic light-emitting technologies, and biological systems. In this article, we have discussed the history, classification, synthetic strategies, physical parameters and mesomorphic studies of five-membered heterocycles beyond biological applications. The liquid crystalline heterocycles that are covered in the review include imidazoles, isoxazoles, isoxazolines, pyrazoles, pyrazolines, thiazoles, thiophenes, 1,2,3- and 1,2,4-triazoles, 1,2,4- and 1,3,4-oxadiazoles, and 1,3,4-thiadiazoles. Overall, the review provides a comprehensive profile of the mesomorphic properties of five-membered heterocydes. (C) 2019 Elsevier B.V. All rights reserved