Orientation in the Crossed Aldol Condensation of Chloral with Unsymmetrical Aliphatic Ketones

1971 ◽  
Vol 49 (10) ◽  
pp. 1588-1597 ◽  
Author(s):  
Eberhard Kiehlmann ◽  
Pui-Wah Loo
Keyword(s):  
Acetic Acid ◽  
Sodium Acetate ◽  
Marked Effect ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Reaction Conditions ◽  
Methyl Group ◽  
Aliphatic Ketones ◽  
Alkyl Groups ◽  
Methylene Group

The reactivity of a series of 14 aliphatic ketones in the crossed aldol condensation with chloral has been studied in glacial acetic acid and in dimethoxyethane. The reaction is irreversible and not accompanied by dehydration of the resulting 1,1,1-trichloro-3-hydroxy-4-alkanones. Except for butanone, condensation occurs preferentially at the least-hindered position of an unsymmetrical ketone. The α-methyl/α-methylene condensation product ratio obtained from ketones of the general formula RCH2COCH3 is higher in acetic acid than in dimethoxyethane as solvent when sodium acetate is used as catalyst. The steric size and chain length of the alkyl groups of methyl alkyl ketones have a marked effect on the reactivity of the α-methyl group toward chloral. Condensation at the α-methylene group results in the formation of diastereomeric ketols which epimerize under the preparative reaction conditions.

scholarly journals rac-N-Benzylisatincreatinine (unknown solvate)

2013 ◽  
Vol 69 (2) ◽  
pp. o290-o291
Author(s):  
Narsimha Reddy Penthala ◽  
Peter A. Crooks
Keyword(s):  
Acetic Acid ◽  
Hydrogen Bonds ◽  
Sodium Acetate ◽  
Aldol Condensation ◽  
Mixed Solvents ◽  
Imidazole Ring ◽  
Ring System ◽  
Dihedral Angles ◽  
Acta Cryst ◽  
Compound C

The title compound, C19H18N4O3[systematic name: (RS)-1-benzyl-3-hydroxy-3-(2-imino-3-methyl-5-oxoimidazolidin-4-yl)-2,3-dihydro-1H-indol-2-one], was prepared as a racemate (RRandSS) by the aldol condensation ofN-benzylisatin with creatinine in the presence of sodium acetate in acetic acid. The r.m.s. deviation of the isatin ring system is 0.033 Å. The benzyl group is disordered over two orientations, with refined occupancies of 0.847 (7) and 0.153 (7). The dihedral angles between the isatin ring system and the benzene ring (major disorder component) and the imidazole ring are 82.82 (7) and 51.31 (3)°, respectively, In the crystal, molecules are linked into (001) sheets by N—H...O and O—H...N hydrogen bonds, which incorporateR22(9) ring motifs. The crystal was grown from mixed solvents (ethanol, methanol and possibly also ethyl acetate). These solvents are disordered in the crystal and the resulting electron density was found to be uninterpretable. The solvent contribution to the scattering was removed with the SQUEEZE routine inPLATON[Spek (2009).Acta Cryst.D65, 148–155]. The formula mass and density do not take account of the solvent.

Isomerizations akin to the Dimroth rearrangement. IV. Formation of simple s-Triazolo[1,5-c]pyrimidines via their [4,3-c] isomers

1978 ◽  
Vol 31 (11) ◽  
pp. 2505 ◽  
Author(s):  
DJ Brown ◽  
T Nagamatsu
Keyword(s):  
Acetic Acid ◽  
Glacial Acetic Acid ◽  
Methyl Groups ◽  
Dimroth Rearrangement ◽  
Methyl Group ◽  
Alkyl Groups ◽  
Ring Fission

Pyrimidin-4-ylhydrazines and simple orthoesters are used in combination (1) to give N-ethoxyalkyl-idene-N'-pyrimidinylhydrazines (2) and thence s-triazolo[4,3-c]pyrimidine (3a) and its 3-, 5-, 7- or 8-alkylated derivatives (3b-s). In glacial acetic acid, these undergo rearrangement into the corresponding s-triazolo[1,5-c]pyrimidines (5) via the acylaminoalkenyltriazoles (4); in aqueous buffers, these reactions stop at the triazoles (4) except in the presence of a 7-methyl group which stimulates completion of the sequence. The ring-fission step, (3) → (4), is retarded markedly by 5- and/or 8-methyl groups but accelerated slightly by 3- and/or 7-alkyl groups; the slower ring-fission of triazolo[1,5-c]-pyrimidines (5) to the same triazoles (4) is retarded by 2-, 5- or 8-alkylation and precluded totally by a 7-methyl group. The recorded u.v. and N.M.R. spectra afford a ready means of distinguishing between the systems (3)-(5).

Condensation of Schiff bases with 2-oxazolin-5-ones: simultaneous introduction of arylidene and amino moieties

1982 ◽  
Vol 60 (3) ◽  
pp. 317-322 ◽  
Author(s):  
Arya K. Mukerjee ◽  
Pradeep Kumar
Keyword(s):  
Acetic Acid ◽  
Schiff Bases ◽  
Sodium Acetate ◽  
Glacial Acetic Acid ◽  
Methyl Group

Schiff bases condense with 2-oxazolin-5-ones having a C-4 methylene and/or C-2 methyl group, and the reaction in glacial acetic acid, containing freshly fused sodium acetate, produces 4-arylidene- and/or 2-styryl-2-imidazoline-5-ones as a result of simultaneous introduction of arylidene and amino moieties.

Chloral–ketone condensations in acetic anhydride. Reaction of chloral with butanone, 3-pentanone, cyclohexanone, and 4-methyl-2-pentanone

1969 ◽  
Vol 47 (11) ◽  
pp. 2029-2037 ◽  
Author(s):  
Eberhard Kiehlmann ◽  
Pui-Wah Loo
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Acetic Anhydride ◽  
Sodium Acetate ◽  
Chloral Hydrate ◽  
Aldol Condensation ◽  
Molecular Model ◽  
Intramolecular Hydrogen Bonding ◽  
Model Studies ◽  
Intramolecular Hydrogen ◽  
Methylene Group

In the presence of sodium acetate as catalyst, chloral hydrate undergoes a mixed aldol condensation with aliphatic and alicyclic ketones in acetic anhydride as solvent. Contrary to previous literature reports, reaction occurs at both the methyl and the methylene group in α-position to the carbonyl group of butanone, to give a mixture of 1,1,1-trichloro-2-hydroxy-4-hexanone (1) and 1,1,1-trichloro-2-hydroxy-3-methyl-4-pentanone (2a and 2b, diastereomers). 3-Pentanone, cyclohexanone, and 4-methyl-2-pentanoneyield 1,1,1-trichloro-2-hydroxy-3-methyl-4-hexanone (3a and 3b, diastereomers), 2-(1-hydroxy-2,2,2-trichloroethyl-) cyclohexanone (4a and 4b, diastereomers), and 1,1,1-trichloro-2-hydroxy-6-methyl-4- heptanone (5), respectively. Compound 5 is the exclusive product formed from chloral hydrate and 4-methyl-2-pentanone since attack at the methylene group is sterically hindered. The low-melting diastereomers 2a, 3a, and 4a which have not been characterized before, exhibit strong intramolecular hydrogen bonding and have been assigned the threo configuration on the basis of nuclear magnetic resonance and molecular model studies.

Reaction of 2-Aryl-4-arylmethylene-2-oxazolin-5-ones with amines

1973 ◽  
Vol 26 (4) ◽  
pp. 827 ◽  
Author(s):  
AM Islam ◽  
AM Khalil ◽  
El-Gawad II Abd
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Aromatic Amines ◽  
Sodium Acetate ◽  
Reaction Conditions ◽  
Primary Aromatic Amines

1,2-Diaryl-4-arylmethylene-2-imidazolin-5-ones were prepared by the interaction of primary aromatic amines with 2-aryl-4-arylmethylene-2- oxazolin-5-ones in the presence of acetic acid and sodium acetate. The same imidazolones were also obtained by the cyclization of the arylamides of α-arylamido-β-arylacrylic acids under the same reaction conditions. A possible reaction mechanism was postulated.

Reaction of 2-(m-Tolyl)-4-arylmethylene-2-oxarolin-5-ones with amines

1973 ◽  
Vol 26 (8) ◽  
pp. 1701 ◽  
Author(s):  
AM Islam ◽  
AM Khalil ◽  
MS El-Houseni
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Aromatic Amines ◽  
Sodium Acetate ◽  
Direct Interaction ◽  
Reaction Conditions ◽  
Primary Aromatic Amines ◽  
Facile Route

A facile route for the preparation of 1,2-diaryl-4-arylmethylene-2-imidazolin-5-ones was established by the direct interaction of primary aromatic amines with 2-(m-tolyl)-4-arylmethylene-2-oxazolin-5-ones in acetic acid containing catalytic amounts of sodium acetate. The same imidazolones were also obtained by cyclization of the aryl- carboxamides of α-arylcarboxamido-β-arylacrylic acids under the same reaction conditions. A possible reaction mechanism was discussed.

The action of arylamines on some substituted 2-Thiazolin-5-ones

1974 ◽  
Vol 27 (9) ◽  
pp. 2035 ◽  
Author(s):  
AM Khalil ◽  
El-Gawad II Abd ◽  
M Hammouda
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Aromatic Amines ◽  
Sodium Acetate ◽  
Heterocyclic Ring ◽  
Reaction Conditions ◽  
Primary Aromatic Amines

The heterocyclic ring in 2-aryl-4-arylmethylene- and 4-arylmethylene-2-benzylthio-2-thiazolin-5-ones is readily opened by the action of primary aromatic amines in acetic acid containing a catalyticamount of sodium acetate with the formation of 1,2-diaryl-4-arylmethylene-2-imidazolin-5-ones and of 3-aryl-5-arylmethylene-2-thiohydantoins respectively. 4-Benzylidene-1-(p-chloropheny1)-2-phenyl-2-imidazolin-5-one was also obtained by the cyclization of the anilide of α-(p-chlorothiobenzamido)-β-phenylacrylic acid under the same reaction conditions. A possible reaction mechanism is postulated.

Characterization of Chemical Impurities in Glutaraldehyde

1975 ◽  
Vol 33 ◽  
pp. 620-621
Author(s):  
B. J. Grenon ◽  
A. J. Tousimis
Keyword(s):  
Glutaric Acid ◽  
Spectroscopic Analysis ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Impurity Component ◽  
Chemical Impurities ◽  
Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

Synthesis and Caracterization of some New 1H-3-aryl-7-etoxycarbonyl-6-methyl-pyrazolo[5,1-c][1,2,4]triazoles

2008 ◽  
Vol 59 (1) ◽  
pp. 41-44
Author(s):  
Maria-Daniela Sofei ◽  
Maria Ilici ◽  
Valentin Badea ◽  
Carol Csunderlik ◽  
Vasile-Nicolae Bercean
Keyword(s):  
Mass Spectrometry ◽  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Sodium Acetate ◽  
Glacial Acetic Acid ◽  
Ir And Nmr Spectroscopy

The synthesis of 1H-3-aryl-7-ethoxycarbonyl-6-methyl-pyrazolo[5,1-c][1,2,4]triazoles (2) was carried out by cyclization of 1H-5-arylidenehydrazino-4-ethoxycarbonyl-3-methyl-pyrazoles (1) in the presence of bromine using glacial acetic acid as solvent and sodium acetate as base. The new nine obtained compounds were characterized by IR and NMR spectroscopy and mass spectrometry.

Novel Synthesis of 4-Benzylidene-2-((1-phenyl-3,4-dihydroisoquinoline-2(1H)-yl)methyl) oxazol-5(4H)-one Derivatives Using 1,2,3,Tetrahydroisoquinoline and their Antimicrobial Activity

2020 ◽  
Vol 17 (5) ◽  
pp. 396-403
Author(s):  
Nalla Krishna Rao ◽  
Tentu Nageswara Rao ◽  
Botsa Parvatamma ◽  
Y. Prashanthi ◽  
Ravi Kumar Cheedarala
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Acetic Acid ◽  
Sodium Acetate ◽  
Good Activity ◽  
Activity Profile ◽  
Aryl Aldehydes ◽  
Chemical Structures ◽  
Novel Synthesis ◽  
Target Molecules

Aims: A series of six 4-benzylidene-2-((1-phenyl-3,4-dihydro isoquinoline-2(1H)-yl)methyloxazol- 5(4H)-one derivatives were synthesized by condensation of substituted aryl aldehydes with 2-(2-(1-phenyl-3,4- dihydro isoquinoline-2(1H)-acetamido)acetic acid in the presence of sodium acetate, acetic anhydride and zinc oxide as catalysts. Background: Novel Synthesis of 4-Benzylidene-2-((1-phenyl-3,4-dihy droisoquinoline-2(1H)-yl)methyl)oxazol- 5(4H)-one derivatives using 1,2,3,Tetrahydroisoquinoline and their antimicrobial activity. Objective: The title compounds can be synthesized from 1,2,3,4-tetrahydroisoquinoline. Methods: The target molecules, i.e., 4-benzylidene-2-((1-phenyl-3, 4-dihydro isoquinoline-2(1H)-yl) methyl) oxazol-5(4H)-one derivatives (8a-8f) have been synthesized from 1,2,3,4-tetrahydroisoquinoline which was prepared from benzoic acid in few steps. Results: All the six compounds were evaluated based on advanced spectral data (1H NMR, 13C NMR & LCMS), and the chemical structures of all compounds were determined by elemental analysis. Conclusion: Antibacterial activity of the derivatives was examined for the synthesized compounds and results indicate that compound with bromine substitution has a good activity profile.

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