Ritter Reactions. XIII Reactivity of Methyl Schiff Bases with Dimethyl Acetylenedicarboxylate and Mercaptoacetic Acid

1998 ◽  
Vol 51 (9) ◽  
pp. 799 ◽  
Author(s):  
Qinghong Lin ◽  
Djamal Djaidi ◽  
Roger Bishop ◽  
Donald C. Craig ◽  
Marcia L. Scudder
Keyword(s):  
Schiff Bases ◽  
New Products ◽  
Mercaptoacetic Acid ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
X Ray Crystallography ◽  
Rearrangement Process ◽  
Ray Methods

Reactions of several methyl imines with dimethyl acetylenedicarboxylate and with mercaptoacetic acid have been studied to investigate further the capricious behaviour of this functionality. The 1 : 1 adduct of imine (1) and dimethyl acetylenedicarboxylate is confirmed as the pyrroloisoquinoline structure (7) by X-ray methods [C17H17NO5, P -1, a 9·037(2), b 9·276(2), c 10·033(2) Å, α 81·99(1), β 81·28(1), γ 64·9(2)°, Z 2, R 0·044]. New products from (2) and dimethyl acetylenedicarboxylate, the 1 : 1 adduct (10) which is readily converted into the known product (9), and the 1 : 2 adduct (12), are described. The structure of the last compound, which arises through a rearrangement process, was determined by X-ray crystallography [C27H36N2O9,P ca21, a 19· 083(4), b 15·217(3), c 9·669(2) Å, Z 4, R 0·038]. Methyl imines (1) and (4) undergo cyclocondensation with mercaptoacetic acid yielding thiazolidinone products but others are inert under similar conditions.

Preparation, Characterisation, Crystal Structure and Antibacterial Activity of two Bis-Schiff Bases Containing a Piperazine Ring

2018 ◽  
Vol 42 (10) ◽  
pp. 512-514
Author(s):  
Rui-bo Xu ◽  
Xiao-tian Yang ◽  
Hai-nan Li ◽  
Peng-cheng Zhao ◽  
Jiao-jiao Li ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Schiff Bases ◽  
Piperazine Ring ◽  
X Ray ◽  
X Ray Crystallography ◽  
Good Antibacterial Activity

Two new bis-Schiff bases containing a piperazine ring, N,N‘-bis(4-chlorobenzylidene)- and N,N‘-bis(4-cyanobenzylidene)-1,4-bis(3-aminopropyl)piperazine, were prepared by the reaction of N,N‘-bis(3-aminopropyl)piperazine with 4-chloro- and 4-cyanobenzaldehyde, respectively. The dichloro compound was fully identified by X-ray crystallography and it exhibited good antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis.

Synthesis and crystal structures of three novel benzimidazole/benzoindolizine hybrids

2016 ◽  
Vol 71 (3) ◽  
pp. 231-239 ◽  
Author(s):  
Roumaissa Belguedj ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
Ali Belfaitah ◽  
Aissa Chibani ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Crystal Structures ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimethyl Maleate

AbstractThree benzoindolizine derivatives, 1, 2, and 3, were obtained via 1,3-dipolar cycloaddition. The reaction of 1-(2′-benzimidazolylmethyl)isoquinolinium ylides with dimethyl acetylenedicarboxylate gave a mixture of pyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (1) and 1,10b-dihydropyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (2) derivatives containing a benzimidazole moiety. The reaction of this isoquinolinium N-ylide with dimethyl maleate gave an unexpected 2,3-dihydropyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate (3). The structures of all reported compounds have been examined by X-ray crystallography, mass spectrometry, and NMR spectroscopy.

The shape of reflections on X-ray, single-crystal photographs (With Plates X and XI)

1945 ◽  
Vol 27 (190) ◽  
pp. 112-125 ◽  
Author(s):  
Kathleen Lonsdale
Keyword(s):  
Wave Length ◽  
Ideal Crystal ◽  
Main Interest ◽  
Small Deviations ◽  
X Ray ◽  
X Ray Crystallography ◽  
Crystal Spacing ◽  
Diffraction Angle ◽  
The Mean ◽  
Ray Methods

In the early days of X-ray crystallography the study of the atomic and molecular structure of crystals was of primary importance. It was more necessary to know the arrangement of the atoms in, say, rocksalt, quartz, diamond, or graphite, than to know the exact distances apart of the atoms, or the small deviations from the mean atomic structure which may result from heat movements, eccentricity of growth, mechanical distortion, and other factors.Now, however, the range of problems is widening, and X-ray methods are being used as a research tool by many workers whose main interest is in other branches of science. It is necessary, therefore, to point out that the familiar Bragg law, nλ = 2d sin θ, which relates order of spectrum n, wave-length λ, crystal spacing d, and diffraction angle θ in an ideal crystal, though still of course applicable, must be applied with some caution to crystals which are not ideal in either structure or texture, and which may be of irregular or eccentric shape.

scholarly journals Reactions of 5-cyano-1,4-diphenylpyridazino[4,5-a]indolizines with dimethyl acetylenedicarboxylate: regioselective formation of 1:2 Michael type adducts

1993 ◽  
Vol 71 (4) ◽  
pp. 529-533 ◽  
Author(s):  
Kiyoshi Matsumoto ◽  
Yukio Ikemi ◽  
Motoo Shiro ◽  
Takane Uchida ◽  
James William Lown
Keyword(s):  
Resonance Structure ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
X Ray Crystallography ◽  
Michael Additions

Reactions of 5-cyano-1,4-diphenylpyridazino[4,5-a]indolizines with dimethyl acetylenedicarboxylate afforded the 1:2 adducts regioselectively and, unexpectedly, in a Michael fashion rather than in a 1,3-dipolar manner. The structure of the products was established by X-ray crystallography. Regiospecific formation of the observed product 3 can be explained by the higher nucleophilicity of the nitrogen at the 2 position than at the 3 position of the 5-cyano-1,4-diphenylpyridazino[4,5-a]indolizine 1 owing to the contribution of a resonance structure 5 to the hybrid. This favors two successive Michael additions to two equivalents of dimethyl acetylenedicarboxylate affording the observed 1:2 adducts 3.

Synthesis and structural characterization of m-terphenyl Schiff base ligands and their aluminum complexes

2004 ◽  
Vol 82 (9) ◽  
pp. 1346-1352 ◽  
Author(s):  
Diane A Dickie ◽  
Hanifa Jalali ◽  
Rahul G Samant ◽  
Michael C Jennings ◽  
Jason AC Clyburne
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Structural Characterization ◽  
Condensation Reaction ◽  
Schiff Base Ligands ◽  
X Ray ◽  
X Ray Crystallography ◽  
Aluminum Complexes

2,4,6-Triphenylbenzaldehyde 1 undergoes a condensation reaction with 2-aminophenol to give N-(2′,4′,6′-triphenylbenzylidene)-2-iminophenol (TPIP) 2. The imine 2 can be reduced with NaBH4 in ethanol to form N-(2′,4′,6′-triphenylbenzyl)-2-aminophenol (TPAP) 3. Addition of trimethylaluminum to 2 or 3 results in the formation of the complexes TPIP-AlMe2·AlMe3 (4) or TPAP-AlMe2 (5). Compounds 2, 3, and 4 have been crystallographically characterized.Key words: N,O ligands, aluminum, m-terphenyl, Schiff bases, X-ray crystallography.

scholarly journals SYNTHESIS, X-RAY CRYSTALLOGRAPHY, MOLECULAR DOCKING AND BIOLOGICAL SCREENING OF 2-AMINOPHENOL BASED SCHIFF BASES

2013 ◽  
Vol 58 (3) ◽  
pp. 1867-1871 ◽  
Author(s):  
MUHAMMAD ASLAM ◽  
ITRAT ANIS ◽  
NIGHAT AFZA ◽  
MUHAMMAD TAHIR HUSSAIN ◽  
RASHAD MEHMOOD ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Schiff Bases ◽  
Biological Screening ◽  
X Ray ◽  
X Ray Crystallography

Applications of the ene reaction. Synthesis and properties of substituted α-methylene-γ-lactones

1981 ◽  
Vol 59 (2) ◽  
pp. 288-301 ◽  
Author(s):  
Alfred W. Hanson ◽  
Archibald W. McCulloch ◽  
A. Gavin McInnes
Keyword(s):  
Starting Material ◽  
Reaction Synthesis ◽  
Dimethyl Acetylenedicarboxylate ◽  
Ene Reaction ◽  
X Ray ◽  
X Ray Crystallography ◽  
Nmr Data ◽  
Predominant Product ◽  
C Nmr

Substituted dimethyl 1,4-pentadiene-1,2-dicarboxylates (1 or 3) may be prepared by AlCl3-promoted or thermal ene reaction of olefins with dimethyl acetylenedicarboxylate. Lactonization of these adducts is catalyzed by acid. In the presence of 80% H2SO4 the predominant product (ca. 80%) is a (Z)-dihydro-3-carbomethoxymethylene-2(3H)-furanone (2 or 4). Cyclization with anhydrous HCl affords a mixture of products, the composition of which depends on the starting material; major products include the corresponding (E)- and δ-lactone isomers (6 and 7). Detailed 1H and 13C nmr data are reported for all compounds. The structures of the (E)-4,5,5-trimethyl-, (Z)-4,5,5-trimethyl-, and (Z)-4,4,5,5-tetramethyl furanone derivatives (6a, 2a, and 2b) have been established by X-ray crystallography. The properties of some of these lactones are discussed, as are possible methods of removal of the carbomethoxyl from 2.

scholarly journals Substituted 4-Acyl-5-methyl-2-phenyl-pyrazol-3-one-phenylhydrazones with Antioxidant Properties: X-Ray Crystal and Spectroscopic Studies

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Omoruyi G. Idemudia ◽  
Anthony I. Okoh ◽  
Alexander P. Sadimenko ◽  
Eric C. Hosten ◽  
Omobola O. Okoh
Keyword(s):  
Free Radical ◽  
Schiff Bases ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Spectroscopic Studies ◽  
Free Radical Scavenging ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Radical Scavenging Properties

Phenylhydrazine was reacted with synthesized acylpyrazolone derivatives 4-ethyl-5-methyl-2-phenyl-pyrazol-3-one and 4-propyl-5-methyl-2-phenyl-pyrazol-3-one, to obtain two new azomethine phenylhydrazones, a study in continuation of our probe into the effects of acyl group substitutions on the physicochemical and free radical scavenging properties of acylpyrazolone Schiff bases. The keto imine tautomers of 4-ethyl-5-methyl-2-phenyl-pyrazol-3-one-phenylhydrazone (Empp-Ph) and 4-propyl-5-methyl-2-phenyl-pyrazol-3-one-phenylhydrazone (Prmpp-Ph) according to single X-ray crystallography data which precipitated in good yield are reported. Furthermore they have been characterized by elemental analysis, FTIR, 13C and 1H NMR, and mass-spectroscopy techniques. Both phenylhydrazone Schiff bases crystallize in a triclinic crystal system, each with a space group of P-1 (number 2) having short intramolecular N3—H3…O1 hydrogen interaction between the first hydrazine hydrogen H3 and the pyrazolone oxygen O1. The antioxidant free radical scavenging activities of titled compounds against 2,2-diphenyl-1-picrylhydrazyl (DPPH) showed a positive response almost as good as that of vitamin c under the same conditions, with the propyl substituted 4-propyl-5-methyl-2-phenyl-pyrazol-3-one-phenylhydrazone (Prmpp-Ph) having a stronger activity (calculated IC50 value of 175.66 μg/ml).

scholarly journals Utilization of 1-phenylimidazo[1,5-a]quinoline as partner in 1,4-dipolar cycloaddition reactions

2020 ◽  
Vol 75 (3) ◽  
pp. 259-267
Author(s):  
Areej M. Jaber ◽  
Jalal A. Zahra ◽  
Mustafa M. El-Abadelah ◽  
Salim S. Sabri ◽  
Monther A. Khanfar ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spectral Data ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
X Ray Crystallography

AbstractA Selected set of 2-(quinolin-2-yl)-1,3-oxazepino[7,6-b]indoles 4a–d and dihydroacenaphtho[1,2-f][1,3]oxazepine 5 have been prepared via 1,4-dipolar cycloaddition reaction involving 1-phenylimidazo[1,5-a]quinoline, dimethyl acetylenedicarboxylate, and N-(substituted)isatins or acenaphthoquinone. Structures of the new heterocycles 4a–d and 5 are supported by NMR and HRMS spectral data, and confirmed by single-crystal X-ray crystallography for 4c and 5.

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