Preparation and molecular structures of N′-(2-heteroarylmethylidene)-3-(3-pyridyl)acrylohydrazides
Abstract The crystal and molecular structures of N′-(2-furylmethylidene)-3-(3-pyridyl)acrylohydrazide and N′-(2-thienylmethylidene)-3-(3-pyridyl)acrylohydrazide are reported, and the influence of the type of the heteroatom on the aromaticity of the aromatic rings is discussed. Both molecules are nearly planar. The geometry of the acrylohydrazide arrangement is comparable to that of homologous compounds. Density functional theory (DFT) calculations were performed in order to analyze the changes in the geometry of the studied compounds in the crystalline state and for the isolated molecule. The most significant changes were observed in the values of the N–N and C–N bond lengths. The harmonic …
3,5-diphenyl-1,2,4-triazin-6(1H)-one: synthesis, and X-ray and DFT-calculated structures.
The title compound, C15H11N3O, (I), was obtained by the air oxidation of 3,5-diphenyl-4,5-dihydro-1,2,4-triazin-6(1H)-one. In the crystal structure, (I) forms centrosymmetric hydrogen-bonded dimers through pairs of N—H...N hydrogen bonds. The molecular structure of (I) deviates somewhat from planarity in the crystalline state, whereas a density functional theory (DFT) study predicts a completely planar conformation (Cspoint-group symmetry) for the isolated molecule. The solid-state conformation of (I) is stabilized by intramolecular hydrogen bonds,viz.one C—H...O interaction, which forms a six-membered ring, and three C—H...N interactions that each form five-membered rings. To estimate the …
π-Electron delocalization in 2-benzoyl-5-phenylpyrazolidin-3-one
Abstract The crystal and molecular structures of 2-benzoyl-5-phenylpyrazolidin-3-one have been characterized by X-ray diffraction along with density functional theory studies. Cinnamic acid chloride was reacted with benzhydrazide, yielding 2-benzoyl-5-phenylpyrazolidin-3-one. This product was formed in the transformation comprising the nucleophilic addition of benzhydrazide to the styryl fragment of the α,β-unsaturated arrangement and subsequent cyclization. The molecule contains two benzene rings and one five-membered heterocyclic ring with an N–N single bond. The five-membered ring is composed of three atoms of sp 3 hybridization and two atoms of sp 2 hybridization, which cause the flatte…
Study on the synthesis of novel 5-substituted 2-[2-(pyridyl)ethenyl]-1,3,4-oxadiazoles and their acid–base interactions
Abstract A series of novel 5-substituted 2-[2-(pyridyl)ethenyl]-1,3,4-oxadiazoles were efficiently synthesized by cyclocondensation of the appropriate 3-(pyridyl)acrylohydrazides with triethyl orthoesters in the presence of glacial acetic acid. The products were identified by means of spectroscopic methods and their pKA ionization constants were determined. The influence of substituents on the basicity of the pyridine system has been discussed. Graphical Abstract
The reaction of optically active α-aminocarboxylic acid hydrazides with triethyl orthoesters
New derivatives of 2-(1-amino-1-phenylmethyl)-1,3,4-oxadiazole and 1,2,4-triazin-6-one were synthesised in the reactions of optically active α-aminocarboxylic acid hydrazides and triethyl orthoesters in xylene. The electronic and steric effects of substituents at the α position influencing the formation of five- or six-membered products are discussed.
1-[(1-ethoxypropylidene)amino]-2-ethyl-4-(4-hydroxybenzyl)imidazol-5(4H)-one.
The racemic title compound, C17H23N3O3, isolated from the reaction of L-(−)-tyrosine hydrazide with triethyl orthopropionate in the presence of a catalytic quantity ofp-toluenesulfonic acid (p-TsOH), crystallizes withZ′ = 1 in a centrosymmetric monoclinic unit cell. The molecule contains two planar fragments,viz.the benzene and imidazole rings, linked by two C—C single bonds. The dihedral angle between the two planes is 59.54 (5)° and the molecule adopts a synclinal conformation. The HOMA (harmonic oscillator model of aromaticity) index, calculated for the benzene ring, demonstrates no substantial interaction between the two π-electron delocalization regions in the molecule. In the crystal …
CCDC 1533753: Experimental Crystal Structure Determination
Related Article: Karolina Jasiak, Agnieszka Kudelko, Katarzyna Gajda, Błażej Dziuk, Bartosz Zarychta, Krzysztof Ejsmont|2018|Z.Naturforsch.,B:Chem.Sci.|73|725|doi:10.1515/znb-2018-0132
CCDC 994076: Experimental Crystal Structure Determination
Related Article: Agnieszka Kudelko, Karolina Jasiak, Krzysztof Ejsmont|2015|Monatsh.Chem.|146|303|doi:10.1007/s00706-014-1355-x
CCDC 994077: Experimental Crystal Structure Determination
Related Article: Agnieszka Kudelko, Karolina Jasiak, Krzysztof Ejsmont|2015|Monatsh.Chem.|146|303|doi:10.1007/s00706-014-1355-x
CCDC 1520500: Experimental Crystal Structure Determination
Related Article: Monika Olesiejuk, Agnieszka Kudelko, Katarzyna Gajda, Błażej Dziuk, Krzysztof Ejsmont|2018|Z.Naturforsch.,B:Chem.Sci.|73|577|doi:10.1515/znb-2018-0072
CCDC 1533752: Experimental Crystal Structure Determination
Related Article: Karolina Jasiak, Agnieszka Kudelko, Katarzyna Gajda, Błażej Dziuk, Bartosz Zarychta, Krzysztof Ejsmont|2018|Z.Naturforsch.,B:Chem.Sci.|73|725|doi:10.1515/znb-2018-0132