Synthesis of procaine analogues containing pentafluoroethoxy groups in the aromatic nucleus

In order to synthesize procaine analogs containing one or two pentafluoroethoxy groups, a method for the synthesis of benzoic acids containing a pentafluoroethoxy group in the ortho-position of the benzene nucleus has been developed. An effective method for the synthesis of procaine structural analogues containing one or two pentafluoroethoxy groups has been proposed. It has been shown that the replacement of the amino group by the pentafluoroethoxy group in the procaine molecule leads to a significant increase in the local anesthetic activity of the obtained compounds. The most active compound was a structural analogue of procainamide containing two pentafluoroethoxy groups in positions 2 and 4. The formation of fluorine-containing analogues of procaine was confirmed by 1H, 19F and 13C NMR spectroscopy and mass spectrometry.

Synthesis and DSSC application of BODIPY decorated triazole bridged and benzene nucleus cored conjugated dendrimers

Dye-sensitized solar cells with BODIPY conjugated dendrimers as the dye are described.

SYNTHESIS AND STRUCTURE OF NEW DERIVATIVES OF 10-R-4-METHYL-1,8-DINITRO-3-OXA-5,10-DIAZATRICYCLO[6.3.1.02.6]DODECA-2(6),4-DIENE

The spatial and electronic structure of 2-methyl-5,7-dinitrobenzo[d]oxazole, which is the substrate for the synthesis of hydride σ-adducts, was studied by the DFT/B3LYP/aug-cc-pVDZ method. Analysis of the charges on the atoms showed that the largest positive NBO charge is concentrated on the carbon atom C2 of the oxazole ring, while the carbon atoms C4 and C6 annelated benzene nucleus have the highest Mulliken charges both in the gas phase and in water. Thus, it has been established that a rigid base, a methoxide ion, is attached to the carbon atom C2, which is a hard reaction center, and a reaction with a soft base, a hydride ion, can also proceed through softer reaction centers — carbon atoms of the benzene ring C4 and C6. The bond lengths calculated by the quantum-chemical method are in good agreement with the experimental data obtained by X-ray diffraction, which confirms the correctness of the choice of the quantum-chemical calculation method. New derivatives of 3-azabicyclo [3.3.1]nonane have been synthesized by Mannich condensation of 2-methyl-5,7-dinitrobenzo[d]oxazole hydride σ-adduct with methylamine and β-aminopropanoic acid. This method is distinguished by relative simplicity, availability of reagents and allows under mild conditions to transfer from the aromatic system activated by nitro groups to 3-azabicyclo[3.3.1]nonane derivatives containing the nitro groups that are promising from the point of view of further functionalization. The structure of the compounds obtained was proved by IR, 1H-, 13C-, two-dimensional correlation NMR spectroscopy, as well as elemental analysis data. It was shown that the compounds obtained can serve as the basis for the creation of hybrid physiologically active compounds containing both a 3-azabicyclononane fragment and an oxazole cycle.

Liquid Crystalline Properties of 4,4and#39;-methylenebis(N-(4-Alkanoxybenzylidene)aniline): Synthesis, Characterization, and Theoretical study

The paper presents six homologues series of Schiff bases ether compounds distinguished by the length of terminal alkoxy groups which substituted on a side benzene nucleus. The above structures were demonstrated through the use of spectroscopic techniques, like FT- IR and 1H-NMR. Polarized hot stage optical microscopy was used to study both mesomorphic properties and phase transitions. The results showed that out of the six compounds only three (B2, B3 and B4) were pure (marble) nematic mesophase, while no liquid crystal properties for (B5, B6 and B7) compounds. The theoretical study for the electronic structures was intended to study the effects of alkyl chain length on the electronic structure by using Gaussian program, DFT and 6-31G as basis set. The theoretical results indicate that there is no effect to the terminal substituted alkoxy groups on the HOMO energies but there is an effect on LUMO energies through decreasing energy for the prepared compounds.

Crystal structure of 1,3-bis(1H-benzotriazol-1-ylmethyl)benzene

The molecular structure of the title compound, C20H16N6, contains two benzotriazole units bonded to a benzene nucleus in ametaconfiguration, forming dihedral angles of 88.74 (11) and 85.83 (10)° with the central aromatic ring and 57.08 (9)° with each other. The three-dimensional structure is controlled mainly by weak C—H...N and C—H...π interactions. The molecules are connected in inversion-related pairs, forming the slabs of infinite chains that run along the [-110] and [110] directions.

Quantification of contributions of different molecular fragments for antioxidant activity of coumarin derivatives based on QSAR analyses

Attempts have been made in the present work using in silico techniques for identification of essential structural features imparting antioxidant potential to naturally available coumarin molecules and their synthetic derivatives. Four different types of modeling tools have been employed for the qualitative and quantitative assessment of the molecular fragments constituting the biological pharmacophore. The descriptor-based quantitative structure–activity relationship (QSAR) and group-based QSAR (G-QSAR) models provide a quantitative estimation of the substituent requirements and the chemical nature of the parent moiety. Subsequently, 3D pharmacophore and hologram QSAR (HQSAR) models enable identification of the key molecular components necessary for the antioxidant potency to the molecules. All of the different models infer the importance of the hydrogen bond acceptor ketonic fragment for interaction of the antioxidant molecules with the neighbouring toxic radicals. Additionally, the phenyl substituent attached to the side chain and the benzene nucleus of the benzopyran moiety also constitute the response pharmacophore for the molecules under study. The models thus developed may serve as an essential query tool for screening of databases for selection of molecules bearing the essential fragments and subsequent prediction of their free radical scavenging potency.

Σχεδιασμός και σύνθεση νέων ετεροκυκλικών και καρβοκυκλικών ενώσεων με μελατονινεργική δράση

In the context of this PhD thesis, the synthesis of a series of fused aromatic carbocyclic and heterocyclic melatoninergic compounds has been undertaken.In the introductory chapter, an account of the endocrinological role of the hormone melatonin in mammals, followed by its therapeutic uses in man, is given. Next, a description of the receptors of melatonin is presented and some of the most interesting published melatoninergics are quoted. The introduction is concluded by a brief albeit detailed description of the aims of the present thesis and the design of the new compounds.In the subsequent chapter, a thorough description of the synthetic routes followed for the preparation of the new molecules, is given. The new melatoninergics belong to various chemical classes, which involve the conformationally constrained indole analogues 5 and 6, the tetracyclic compounds II, 12, 13 and 17, their analogues 25-27, 31, 32, 46-48, 53-55 and 39-41 and 65. Apart from these series, new cyclobuta- and cycloheptarenes, compounds 69-71, 77-79, 81-83, 87-89 and 102-104, 114-116, respectively were also prepared. The synthetic part of this chapter is concluded with the methods of preparation of the benzocycloheptenes 96-98 and 111-113.The new molecules were tested for their pharmacological activity, using the well-established Xenopus laevis pigment aggregation model. The indole analogues 5 and 6 are melatonin receptor agonists, with an affinity higher than that of melatonin. The tetracyclic compounds 12 and 13 are melatonin receptor agonists, whilst their gem-dimethyl side chain substituted congeners, II and 17, are partial agonists. Their analogues 25-27, 31, 32, 46-48, exhibit variable melatonin receptor activity ranging from pure agonistic (25-27) to pure antagonistic 31, 32, 46-48 and 53-55. Conversely, their congeners 39-41 and 65 are all pure antagonists. The action of the cyclobutarenes 69-71, 77-79, 81-83, 87-89 varies in accordance with the number of MeO substituents on the benzene nucleus and/or the length of the R group in the side chain. Thus, all the R2 (77-79) and R3 (81-83) monomethoxylated analogues are agonists. Conversely, with the exception of compound 69, their R1 monomethoxylated congeners 70 and 71 are partial agonists. The bis-methoxylated cyclobutarenes 88 and 89 are melatonin receptor agonists, whereas their counterpart 87 (R=Me) is a partialagonist. The cycloheptarenes 102-104 and 114-116 are all antagonists in the Xenopus model, whereas their benzocycloheptene congeners are either pure agonists (96-98) or pure antagonists (compounds 111-113).All new compounds possess stereoelectronic features, which enable them to act as agonist-partial agonist-antagonist molecular probe ―switches‖. An extension of the present thesis could involve the enantioselective synthesis of the most active racemic cyclobuta- and cycloheptarenes.