Search results for "Schiff Base"

Synthese von 2-alkoxysubstituierten Oligo- und Poly(1,4-phenylenethenylen)en und 2-Arylbenzo[b]furanen mit Hilfe der Siegrist-Reaktion

1994

Synthesis of 2-Alkoxy Substituted Oligo- and Poly(1,4-phenyleneethylene)s and 2-Arylbenzo[b]furanes by Applying the Siegrist Reaction Alkylation of 2-hydroxy-4-methylbenzaldehyde (1) yields the 2-alkoxy-4-methylbenzaldehydes (2a-l) which can be easily transformed to the Schiff bases 3a-l. The intermolecular self-condensation in a strongly alkaline medium leads to the oligo- and poly(1,4-phenyleneethenylene)s (4a-i) with an outstanding regular constitution and overall (E)-configuration. The terminal N-arylamino group can be cleaved by hydrolysis generating the compounds 5a-i. An intramolecular condensation forming the benzo[b]furanes 6j,k is observed for 3j,k – due to the activated OCH2 grou…

Iron(III) Clusters from Polydentate Schiff Base Ligands: Involvement of Non Heisenberg Interaction in [FeIII 3(µ2-OR)3(µ2-O2CPh)3]3+ Clusters

2018

On the reactions between ethyl benzoylacetate and anisidines

1975

4-Hydroxy-7-methoxy-3-[(m-methoxyphenylimino)-phenylmethyl]-2-quinolone (6) was a by-product of the condensation of ethyl benzoylacetate and m-anisidine; no corresponding products were obtained from p- and o-anisidine. From o-anisidine, 2-phenyl-8-methoxy-4-quinolone (1c) was isolated and characterized; the same reaction also gave 2-phenyl-4-o-anisidyl-1-8-methoxy-quinoline (11) and the Schiff base (14) as by-products; the crotonamide (15) also isolated, is a possible intermediate of the cyclization. The direct condensation of anisidines with ethyl benzoylacetate in diphenyl ether and the transformations of some intermediates were studied.

ChemInform Abstract: STUDIES ON THE SYNTHESIS OF HETEROCYCLIC COMPOUNDS. PART X. ONE-STEP ROUTE TO O 1,2-DIMETHYL-3-R-5-SALICYLOYLIMINO-3-PYRAZOLINES

1984

This communication outlines the development of a direct synthetic route to 1,2-dimethyl-3-R-5-salicyloyl-imino-3-pyrazolines, starting from readily available 3(5)-aminopyrazoles 1a, b, c and methyl salicylate. The structures of the new compounds 3a, b, c were determined on the basis of analytical and spectroscopic data as well as on the acid hydrolysis products.

Crystal structure of (E)-4-methyl-N-{2-[2-(4-nitrobenzylidene)hydrazin-1-yl]-2-oxoethyl}benzenesulfonamideN,N-dimethylformamide monosolvate

2017

The molecule of the title Schiff base compound, C16H16N4O5S·C3H7NO, displays atransconformation with respect to the C=N double bond. The C—N and N—N bonds are relatively short compared to their normal bond lengths, indicating some degree of delocalization in the molecule. The molecule is bent at the S atom, with an S—N—C—C torsion angle of 164.48 (11)°. The dihedral angle between the two aromatic rings is 84.594 (7)°. Intermolecular N—H...O and C —H...O hydrogen bonds connect centrosymmetrically related molecules into dimers forming rings ofR33(11) andR22(10) graph-set motif stacked along theaaxis into a columnar arrangement. The molecular columns are further linked into a three-dimensional…

Crystal structure ofS-octyl (E)-3-(4-methoxybenzylidene)dithiocarbazate

2015

As already observed in similar molecules, the dithiocarbazate group in the title compound, C17H26N2OS2, adopts anEEconfiguration with respect to the C=N bond of the benzylidene moiety. In the crystal, molecules are connected into inversion dimers by pairs of N—H...S hydrogen bonds. The dimers are linked by weak π–π interactions, with centroid-to-centroid distances of 3.723 (11) Å, forming chains parallel to [110].

Crystal structure, Hirshfeld surface analysis and HOMO–LUMO analysis of (E)-4-bromo-N′-(4-methoxybenzylidene)benzohydrazide

2018

The title Schiff base compound, C15H13BrN2O2, displays an E configuration with respect to the C=N double bond, which forms a dihedral angle of 58.06 (9)° with the benzene ring. In the crystal, the molecules are linked into chains parallel to the b axis by N—H...O and C—H...O hydrogen bonds, giving rise to rings with an R 2 1(6) graph-set motif. The chains are further linked into a three-dimensional network by C—H...π interactions. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from C...H (33.2%), H...H (27.7%), Br...H/H...Br (14.2%) and O...H/H...O (13.6%) interactions. The title compound has also been characterized by frontier molecu…

Crystal structure of (E)-N-(3,4-di­meth­oxy­benzyl­idene)morpholin-4-amine

2014

In the title compound, C13H18N2O3, the benzene ring makes a dihedral angle of 17.19 (11)° with the least-squares plane formed by the four C atoms of the morpholine ring, which adopts a chair conformation. In the crystal, C—H...N hydrogen bonds link the molecules into supramolecular chains running along a 21screw axis parallel to theb-axis direction. Weak C—H...π interactions are also observed.

A tetranuclear cubane-like nickel(II) complex with a tridentate salicylideneimine Schiff base ligand: tetrakis[μ3-4-methyl-N-(2-oxidophenyl)salicylid…

2016

The tetranuclear title complex, [Ni4(C14H11NO2)4(CH3OH)4]·0.8CH3OH, has a distorted cubane topology shaped by four Schiff base ligands. The cubane [Ni4(μ3-O4)] core is formedviathe O atoms from the Schiff base ligands. The octahedrally coordinated NiIIions occupy alternating vertices of the cube. Each NiIIion is coordinated by oneO,N,O′-tridentate dianionic ligand, two O atoms of oxidophenyl groups from adjacent ligands and the O atom of a coordinating methanol molecule. The cubane core is stabilizedviaan intramolecular O—H...O hydrogen bond between the hydroxy group of the coordinating methanol molecules and the phenolate O atom of the aldehyde Schiff base fragment. Additional stabilizatio…

Crystal structure, Hirshfeld surface analysis and HOMO–LUMO analysis of (E)-N′-(3-hydroxy-4-methoxybenzylidene)nicotinohydrazide monohydrate

2019

The title Schiff base compound displays an E configuration with respect to the C=N double bond. The pyridine and benzene rings subtend a dihedral angle of 29.63 (7)°. In the crystal, the mol­ecules are linked by N—H⋯O, C—H⋯O, O—H⋯O and O—H⋯N hydrogen-bonding inter­actions.