A new type of acid-induced intramolecular cyclisation of Knoevenagel condensation products in the carbohydrate field. Stereochemical control of the cyclisation process.

1980 ◽  
Vol 21 (51) ◽  
pp. 4963-4966 ◽  
Author(s):  
F.J. López Herrera
Keyword(s):  
Knoevenagel Condensation ◽  
Condensation Products ◽  
Stereochemical Control ◽  
New Type

New Condensation Products of Rubber Hydrocarbons by the Aid of Benzyl Chloride

1932 ◽  
Vol 5 (2) ◽  
pp. 110-116
Author(s):  
F. Kirchhof
Keyword(s):  
Aluminum Chloride ◽  
Benzyl Chloride ◽  
Condensation Product ◽  
Chemical Properties ◽  
Metal Chlorides ◽  
Condensation Products ◽  
New Type ◽  
The One ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract The application of the long-known Friedel-Crafts reaction to rubber hydrocarbons led to a new type of condensation products which may be called provisionally aral cyclorubbers (“benzylidene rubbers”), since their benzylidene groups are probably condensed with the polyprene skeleton to cyclic systems. It would not have been foreseen without further work that rubber would form this type of condensation product with aral halides in the presence of aluminum chloride, since on the one hand benzyl chloride is known to form, by the action of aluminum chloride in the Friedel-Crafts reaction, an amorphous, apparently high molecular hydrocarbon of the empirical composition (C7H6)x, and on the other hand rubber in solution is transformed by the metal chlorides, especially aluminum chloride, into amorphous polycyclorubbers. Under definite conditions of condensation with aluminum chloride aral groups are combined with the skeleton of the rubber hydrocarbon with the formation of white to yellowish amorphous bodies which contain, in addition to a small proportion of organically combined chlorine, only carbon and hydrogen, and are therefore to be regarded as hydrocarbons. In their physical and chemical properties these substances resemble the already known amorphous substance of the empirical formula (C7H6)x, which doubtless is polybenzylidene, probably hexabenzylidene.

Synthesis, optical, and spectroscopic characterisation of substituted 3-phenyl-2-arylacrylonitriles

2011 ◽  
Vol 65 (1) ◽  
Author(s):  
M. Percino ◽  
Víctor Chapela ◽  
Enrique Pérez-Gutiérrez ◽  
Margarita Cerón ◽  
Guillermo Soriano
Keyword(s):  
Knoevenagel Condensation ◽  
Cyano Group ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Fluorescence Emission Spectra ◽  
Condensation Products ◽  
Pyridine Moiety ◽  
Methylene Groups ◽  
Active Methylene ◽  
Spectroscopic Characterisation

AbstractThe Knoevenagel condensation between aldehydes and substrates with active methylene groups was applied to synthesise a series of 3-(4-substituted phenyl)-2-arylacrylonitriles (aryl = phenyl or pyridyl). Chloro-, fluoro-, or dimethylamino-substituted aryls and a cyano group attached to the double bond of acrylonitrile were studied. Previous studies showed that the condensation products were E isomers. The compounds synthesised were: 3-(4-chlorophenyl)-2-phenylacrylonitrile, 3-(4-chlorophenyl)-2-(pyridin-2-yl)acrylonitrile, 3-(4-chlorophenyl)-2-(pyridin-3-yl)acrylonitrile, 3-(4-chlorophenyl)-2-(pyridin-4-yl)acrylonitrile, 3-(4-fluorophenyl)-2-phenylacrylonitrile, 3-(4-fluorophenyl)-2-(pyridin-2-yl)acrylonitrile, 3-(4-fluorophenyl)-2-(pyridin-3-yl)acrylonitrile, 3-(4-fluorophenyl)-2-(pyridin-4-yl)acrylonitrile, 3-(4-dimethylaminophenyl)-2-phenylacrylonitrile, 3-(4-dimethylaminophenyl)-2-(pyridin-2-yl)acrylonitrile, 3-(4-dimethylaminophenyl)-2-(pyridin-3-yl)acrylonitrile, and 3-(4-dimethylaminophenyl)-2-(pyridin-4-yl)acrylonitrile. Structures were confirmed by IR, MS, and NMR spectral data. Molar absorption coefficient, absorbance, and fluorescence emission spectra were compared in order to evaluate the effects of substituents on phenyl and the position of nitrogen in pyridine moiety on the electronic properties of acrylonitrile derivatives prepared.

Reactions of 1-cyano-1-R-2-(5-X-2-furyl)ethylenes with nucleophilic reagents

1984 ◽  
Vol 49 (9) ◽  
pp. 2141-2147 ◽  
Author(s):  
Rudolf Kada ◽  
Viera Knoppová ◽  
Jaroslav Kováč ◽  
Naděžda Mäčková
Keyword(s):  
Knoevenagel Condensation ◽  
Nucleophilic Substitutions ◽  
Condensation Products ◽  
Nucleophilic Reagents

The Knoevenagel condensation of phenylsulphonylacetonitrile and benzoylacetonitrile with 5-X-furane-2-carbaldehydes ( X = Br, NO2, C6H5S, C6H5SO2) has been used for preparation of the respective condensation products 1-cyano-1-fenylsulphonyl-2-(5-X-2-furyl)- and 1-cyano-1-benzoyl-2-(5-X-2-furyl)ethylenes. These condensation products react with nucleophilic reagents which replace the group X at the 5 position of the furane nucleus. These nucleophilic substitutions have been also studied kinetically.

Synthesis and antimicrobial evaluation of some heterocyclic compounds from 3-aryl-1-phenyl-1H-pyrazole-4-carbaldehydes

2018 ◽  
Vol 73 (6) ◽  
pp. 389-397 ◽  
Author(s):  
El Sayed Ramadan ◽  
Essam M. Sharshira ◽  
Ramadan I. El Sokkary ◽  
Noussa Morsy
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Heterocyclic Compounds ◽  
Knoevenagel Condensation ◽  
Green Solvent ◽  
Condensation Products ◽  
Diffusion Technique ◽  
Lactam Antibiotic ◽  
Antimicrobial Evaluation

AbstractA new series of chalcones, pyrazolinyl-pyrazoles, pyrazole-4-carbaldehyde oximes, pyrazole-4-carbonitriles, 5-pyrazolyl-1,2,4-triazolidine-3-thiones, and Knoevenagel condensation products was synthesized from 3-aryl-1-phenyl-1H-pyrazole-4-carbaldehydes. Most reactions were carried out either without solvent or in the presence of water as a green solvent. The structure of synthesized compounds was characterized by spectral and elemental analysis. The synthesized compounds were tested in vitro for their antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans in comparison with imipenem (intravenous β-lactam antibiotic) and clotrimazole (antifungal medication) as reference drugs by using the agar diffusion technique. 3-Aryl-1-phenyl-1H-pyrazole-4-carbonitriles 8b, 8c, and 8d showed significant antifungal activity against the fungus C. albicans.

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