Search results for "ZOL"
showing 10 items of 4792 documents
From 2000 to Mid-2010: A Fruitful Decade for the Synthesis of Pyrazoles
2011
An efficient synthesis of new fluorinated uracil derivatives.
2003
A series of potentially biologically active fluorinated uracil derivatives has been prepared in three steps from oxazolines and fluorinated nitriles with good chemical yields. Fustero Lardies, Santos, Santos.Fustero@uv.es ; Sanz Cervera, Juan Francisco, Juan.F.Sanz@uv.es ; Asensio Martinez, Amparo, Amparo.Asensio@uv.es
Measured and Modeled Residue Dynamics of Famoxadone and Oxathiapiprolin in Tomato Fields
2018
A reliable analytical method for the simultaneous determination of famoxadone and oxathiapiprolin dissipation kinetics as well as the metabolites of oxathiapiprolin (IN-E8S72 and IN-WR791) in tomato and soil was developed. We studied the dissipation of famoxadone and oxathiapiprolin in tomatoes grown using different kinetic curves in the area of Beijing in 2015 and 2016. Our results show that the most suitable model for two fungicides in 2015 and 2016 was first-order kinetic and second-order kinetic with the half-lives of 3.4 to 5.2 and 2.4 to 3.0 days, respectively. In addition, we applied the dynamic plant uptake model dynamiCROP and combined it with results from the field experiments to …
The Reaction of 4-Amino-2-oxazolines with Isocyanates and Isothiocyanates. Synthesis and X-Ray Structures of Polysubstituted 2-Imidazolidinones, 1,3-…
2006
Abstract Reactions of 4-alkylamino-2-phenyl-2-oxazolines 1 with isocyanates and isothiocyanates provide unprecedented efficient and regioselective heterocycle–heterocycle transformations. Compounds 1 reacted rapidly with tosyl isocyanate yielding directly 3-alkyl-4-benzamido-1-tosyl-2-imidazolidinones 4 in almost quantitative yields. The corresponding ureido intermediates 2 were not isolable species. However, the reactions with non-sulfonylated isocyanates or isothiocyanates were slower, leading to the expected ureido and thioureido derivatives 5, which were easily and efficiently transformed to either polysubstituted 2-imino-1,3-oxazolidine or 2-imino-1,3-thiazolidine hydrochlorides 7, res…
Monitoring the hydrogen bond net configuration and the dimensionality of aniline and phenyloxamate by adding 1 H -pyrazole and isoxazole as substitue…
2019
This work describes the synthesis and characterization of a new class of oxamic acid derivatives containing pyrazole and isoxazole as substituents to investigate their ability to form hydrogen bonds aiming at applying them in crystal engineering and molecular self-recognition. In this respect, we report a new synthesis of 2-(4-nitrophenyl)-1,3-propanedial (1) in high yield using SOCl2 as a chlorinating agent. The new oxamic esters 4-(1H-pyrazol-4-yl)phenylene-N-(ethyloxamate) (2d) and 4-(1,2-oxazol-4-yl)phenylene-N-(ethyloxamate) (3d) were prepared from 1. The synthetic route consists of the cyclisation of 1 either with hydrazine to afford 4-(-aminophenyl)-1H-pyrazole (2a) or with hydroxyla…
4-[5-(4-Fluorophenyl)-3-isopropylisoxazol-4-yl]pyridin-2(1H)-one
2007
The crystal structure of the title compound, C17H15FN2O2, was determined as part of a study of the biological activity of pyridine-substituted isoxazole derivatives as mitogen-activated protein kinase (MAPK) inhibitors. In the crystal structure of the title compound, the compound exists in the lactam and not in the tautomeric pyridin-2-ol form. As the aromatic pyridine nitrogen is considered to be important for accepting a hydrogen bond from p38MAPK, the structure of the lactam unit is correlated with the loss of biological activity of the title compound in the p38MAPK assay. In the crystal structure, the lactam is involved in hydrogen bonds, forming chains along the b axis.
Combined study of anion recognition by a carbazole-based neutral tripodal receptor in a competitive environment
2012
Anion recognition studies have been carried out on a series of neutral synthetic receptors in which carbazole-2-carboxamide has been used as building block. Different ligands which include one to three carbazole units in their structure have been prepared. Binding experiments have been performed under competitive conditions in DMSO and DMSO-water solutions. The tripodal receptor offered a better host-guest association due to the synergistic effect of a well arranged set of hydrogen bonds. A selective response towards the biologically important pyrophosphate anion has been achieved. This selectivity is enhanced when studies are carried out with an increasing water content, which gets as high…
1-[(1-ethoxypropylidene)amino]-2-ethyl-4-(4-hydroxybenzyl)imidazol-5(4H)-one.
2012
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 …
Hydrogen-bonded 2-(2-pyridyl)imidazole (pyim) manganese(II) complexes as building blocks for molecular assembling: Syntheses and structural character…
2008
Abstract The preparation and crystal structures of three new manganese(II) complexes with 2-(2-pyridyl)imidazole (pyim) and pseudohalides as ligands, cis-[Mn(pyim)2(N3)2] (1), cis-[Mn(pyim)2(NCO)2] (2) and cis-[Mn(pyim)2(NCS)2] (3), are reported. The structural building block in each structure is a mononuclear, neutral complex unit. The metal ion in each case adopts a distorted octahedral coordination geometry with the two pseudohalide ligands in cis positions. The main differences between the molecular structures of the three compounds are associated with the orientation of the anionic ligands. Hydrogen bonds between imidazole N–H and the metal-coordinated nitrogen atom of the pseudohalide…
Ethyl 5-amino-3-(pyridin-4-yl)-1-(2,4,6-trichlorophenyl)-1H-pyrazole-4-carboxylate dimethyl sulfoxide hemisolvate
2012
The asymmetric unit of the title compound, C17H13Cl3N4O2·0.5C2H6OS, contains two almost identical molecules and one dimethyl sulfoxide (DMSO-d6) solvent molecule. The pyrazole ring forms dihedral angles of 54.6 (4) and 80.0 (4)° in one molecule, and dihedral angles of 54.2 (4) and 81.2 (4)° in the other molecule, with the directly attached pyridine and trichlorophenyl rings, respectively. The dihedral angles of the pyridine and trichlorophenyl rings are 51.2 (4) and 52.0 (4)°, respectively. The crystal packing is characterized by intra- and intermolecular hydrogen bonds. The crystal is a nonmeroh…