Styryl Ketones Research Articles

Substituent Effect on the Infrared Spectra of Thiazolyl Styryl Ketone

A series of p-substituted thiazolyl styryl ketones were synthesized by the Claisen -Schmidt condensation of various substituted benzaldehydes with 5-acetyl-2,4-dimethyl thiazole. The IR spectra for all the chalcones were recorded and effect of substituent on the carbonyl and C=N stretching frequencies are analyzed.

Discovery of Bis-sydnone styryl ketone as a selective cyclooxygenase-2 inhibitor

BackgroundVarious literature sources have documented a wide spectrum of therapeutic properties of sydnones including anti-inflammatory, anticancer, antimicrobial activities. Phenyl styryl ketones and their derivatives as members of the chalcone family have also been reported as significant bioactive molecules. The current study was initiated to evaluate the anti-inflammatory activity of sydnone-based compounds including some novel bis-sydnone styryl ketone hybrids.ResultsTwenty-five sydnone-containing compounds were successfully synthesized. Compounds 46-48 and 56-58 were reported as new sydnone derivatives. Whereas, compounds 61-63 were synthesized as novel molecules containing two sydnone rings linked via α,β-unsaturated ketone. The structures of the synthesized compounds were confirmed by FTIR, 1H NMR, 13C NMR and ToF-MS analyses. The in vitro COX inhibition assay showed varied activity. Compounds 47, 51, 58 and 63 showed the most potent COX inhibitory effects at a concentration of 200 μM. The selectivity index revealed that 63 was the best selective COX-2 inhibitor. Acetylation of the sydnone ring at C-4 was fruitful for the COX inhibitory effects. Docking analysis showed that COX-2 selectivity was due to a favourable positive charged interaction occurring between the sydnone ring of 63 and Arg513 of COX-2. Compound 51 was hydrogen bonded to Arg513. On the other hand, the low inhibitory effect of 63 against COX-1 was due to an unfavourable polar interaction with His513 in the binding pocket of COX-1.ConclusionsThe compounds were successfully synthesized and characterized. Compound 63 had a common architecture and pharmacophoric features with known selective COX-2 inhibitors (the coxib family) which make it a suitable candidate for the designing of selective and safe NSAID.

Novel Diazenyl Containing Phenyl Styryl Ketone Derivatives as Antimicrobial Agents.

Background: Antibiotics play an important role in the treatment of infections to the hu-mans and at the same time, irrational, frequent prescription of higher antibiotics, change in gene com-position of microorganisms are all the reasons behind the development and introduction of new anti-biotics against different microorganisms.Objective: In this project, an attempt has been made to synthesize some derivatives of diazenyl con-taining phenyl styryl ketones and also their in vitro screening was conducted against Mycobacterium tuberculosis, Escherichia coli, Klebsiella pneumonia, Bacillus subtilis, Staphylococcus aureus, As-pergillus niger and Candida albicans.Methods: Ten molecules were synthesized which are diazenyl containing chalcones. 4-aminoacetophenone was diazotised and piperidine was coupled with the formed diazonium chloride. Further, the acetoxy group underwent Claisen-Schmidt condensation with differently substituted al-dehydes to form the final compounds- the chalcones. The proposed chemical structures were con-firmed by different spectroscopic techniques like FTIR, 1H NMR and Mass spectroscopy. TLC was used to know that the reactants were exhausted and the formation of the product occurred. Sharp melting point of the compounds concludes the purity.Results: The MIC of the compounds 3CP, 3DP, 3EP and 3GP is 20 times the MIC of the standard fluconazole drug against Aspergillus niger. The compound 3GP is as equipotent as the standard drug Pyrazinamide with MIC of 3.12 µg/ml against Mycobacterium tuberculosis.Conclusion: The results are quite promising which on further studies may lead to drug molecules against different microorganisms. Especially, 3EP can be considered as a broad spectrum agent due to its potent activity against different microorganisms like Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and Candida albicans

Poly[4-pyridinyl-4´-(2-methacryloyloxyethoxy)styryl ketone-co-2-hydroxypropyl methacrylate]: Synthesis, Characterization, Thermal and Electrical properties, and Photocrosslinking behavior

Synthesis of a chalcone bearing pyridine ring, 4-pyridinyl-4´-(2-hydroxyethoxy)styryl ketone, was carried out from the reaction of 4-acetyl pyridine and 4-(2-hydroxyetoxy)benzaldehyde in an aqueous solution of NaOH. 4-Pyridinyl-4´-(2-methacryloyloxyethoxy)styryl ketone which is the methacrylate monomer bearing chalcone structure in side chain, was obtained from acylation of 4-pyridinyl-4´-(2-hydroxyethoxy)styryl ketone with methacryloyl chloride in the cold. The copolymer of 4-pyridinyl-4´-(2-methacryloyloxyethoxy)styryl ketone and 2-hydroxypropyl methacrylate was prepared by free radical polymerization in presence of AIBN at 70 oC. FTIR, 1H-NMR and 13C-APT spectroscopic techniques were used for structural characterization of the Chalcone, the monomer and the copolymer. Thermal characterization of the copolymer was carried out using DSC and TGA techniques. DSC curve shows that this copolymer has a glass transition temperature of 78 oC. The TGA curve shows that decomposition given volatile product started at 230 °C and a residue of 21% left at 500 °C. Dielectric constant (ε´) of the copolymer decreased rapidly from 8.8 to 4.2 with increasing frequency in the range of 100-1000 Hz, and after this frequency ε´ quantity remained constant at a value such as 4.2. ε´ Value of the copolymer increased only from 4.2 to 4.9 with increasing from 290 K to 385 K. The AC conductivity of the copolymer increases from 5.01x10-10 S/cm to 126.0x10-10 S/cm as the frequency increase from 100 Hz to 5000 Hz. The AC conductivity increases slightly with increasing temperature, 2.52x10-9 S/cm at 300 K, and 2.89x10-9 S/cm at 385 K. After a solution of the copolymer was irradiated using UV light at 365 nm at room temperature, the absorption band at 356 nm disappeared and a new band was seen at 284 nm.

ChemInform Abstract: Chiral Phase‐Transfer‐Catalyzed Intramolecular Aza‐Michael Reactions for the Asymmetric Synthesis of Isoindolinones.

AbstractA novel synthetic route to optically active isoindolinones is achieved by asymmetric intramolecular aza‐Michael reaction of ortho‐carbamoyl substituted styryl ketones (I) and (III) in the presence of the oligomeric cinchonium phase‐transfer catalyst (QNC).

Synthesis, biological evaluation, and molecular docking studies of N-(α-acetamido cinnamoyl) aryl hydrazone derivatives as antiinflammatory and analgesic agents

A series of acyl hydrazone derivatives were synthesized and screened for antiinflammatory and analgesic activities. The N-acylarylhydrazone compounds described herein were designed by combining the pharmacophoric features of hydrazones and styryl ketones in order to identify the pharmacophoric contribution of the N-acylarylhydrazone moiety and to study the structure–activity relationships. In carrageenan-induced paw edema test, N′-(4-hydroxy benzylidene)-2-acetamido-3-phenyl propenohydrazide (6j) reduced edema by 74 % which is comparable to the standard reference drug, phenylbutazone at equidose. N′-(4-methoxy benzylidene)-2-acetamido-3-phenyl propenohydrazide (6g) showed analgesic activity (68 %) which is equipotent to the standard drug, aspirin (64 %). Molecular docking studies further confirmed that 6j showed better binding affinity with COX-2 and LOX-5 with reduced gastric ulcerogenic effect when compared to phenylbutazone.

Spectral and computational studies in substituted pyrrolyl styryl ketones – Assessment of substituent effects

A series of newly synthesized potent bioactive 2-pyrrolyl styryl ketone derivatives were characterized by spectral techniques. The effect of substituent on the absorption maximum, IR stretching frequencies and NMR chemical shifts were investigated. DFT calculations were made to calculate HOMO–LUMO energies and natural bond orbital analysis [NBO]. The electric dipole moment (μ) and the hyperpolarisability (β) of the investigated molecules have also been studied and found that these synthesized molecules exhibits microscopic non-linear optical (NLO) behavior with non-zero tensor components.

An Atom-Economical Approach to the Synthesis of Potentially Bioactive 2H-Chromenes via CuI-Catalyzed Reactions of Alkyl/Aryl-(E)-(o-Propar­gyloxy)styryl Ketones

A series of potentially bioactive 2<i>H</i>-chromenes have been synthesized in good yields (60–82%) via CuI-catalyzed reactions of alkyl/aryl-(<i>E</i>)-(<i>o</i>-propargyloxy)styryl ketones in an atom-economical approach.

Design, Synthesis and Biological Evaluation of Hybrid Molecules Containing Conjugated Styryl Ketone and &amp;#945;-Bromoacryloyl Moieties

There was a major interest in the last years in the design of anticancer agents containing the 1,5-diaryl-3-oxo- 1,4-pentadienyl system. The modification of this pharmacophore by the introduction of an additional Michael acceptor represents a strategy to obtain novel potential antiproliferative agents. In a continuing study of hybrid compounds containing the α-bromoacryloyl moiety as potential anticancer drugs, we synthesized two novel series of hybrids 3a-i and 4a-i, in which this moiety was linked to the 1,5-diaryl-1,4-pentadien-3-one system. Many of the conjugates prepared (3b, 3c and 3g) demonstrated pronounced antiproliferative activity against five cancer cell lines, being more active than the reference compound Melphalan. Compounds 3e and 4b were also examined for their effects on the cell cycle progression of K562 cells. The detection of a sub-G1 peak upon incubation with these compounds suggested that 3e and 4b also exert their growth inhibiting effects by induction of apoptosis.

Phosphine-catalyzed [4 + 2] annulation and vinylogous addition reactions between 1,4-dien-3-ones and 1,1-dicyanoalkenes

Phosphine-catalyzed [4 + 2] annulation and vinylogous Michael addition reactions between 1,4-dien-3-ones and 1,1-dicyanoalkenes are presented. Under the catalysis of PBu(3) (20 mol %), 1,4-dien-3-ones like styryl ketones with 2-aryl 1,1-dicyanoalkenes as doubly activated alkenes readily undergo a formal [4 + 2] cycloaddition reaction, affording polysubstituted cyclohexanones in satisfactory yield and good diastereoselectivity; with the doubly activated alkenes bearing an acidic methyl or methylene at the 2-position, a vinylogous Michael addition of 1,4-dien-3-ones occurs under the same reaction conditions, giving a non-cyclized multifunctional adduct in good yield. These two phosphine-catalyzed transformations represent atom economical carbon-carbon bond forming reactions capable of rapid construction of molecular complexity. Based on experimental results, formation of the products has been mechanistically rationalized, and a phosphonium activation is proposed.

One-Pot Synthesis of (E)-Styryl Ketones from Styrenes

A new, efficient protocol for the highly stereoselective one-pot synthesis of (E)-styryl ketones from styrenes based on sequential ruthenium-catalyzed silylative coupling-rhodium-catalyzed desilylative acylation reactions is reported.

Fluorine bearing sydnones with styryl ketone group: synthesis and their possible analgesic and anti-inflammatory activities

In continuation of structure activity relationship studies, a panel of fluorine containing sydnones with styryl ketone group 4-[1-oxo-3-(substituted aryl)-2-propenyl]-3-(3-chloro-4-fluorophenyl)sydnones 2a–i, was synthesized as better analgesic and anti-inflammatory agents. The title compounds were formed by condensing 4-acetyl-3-(3-chloro-4-fluorophenyl)sydnone with various substituted aryl aldehydes, characterized by spectral studies and evaluated at 100 mg\\kg b.w., p.o. for analgesic, anti-inflammatory and ulcerogenic activities. Compounds 2c and 2e showed good analgesic effect in acetic acid-induced writhing while none showed significant activity in hot plate assay in mice. In carrageenan-induced rat paw oedema test, compound 2c and 2f exhibited good anti-inflammatory effect at 3rd h, whereas compounds 2c, 2e, 2d, 2g and 2h showed activity in croton oil induced ear oedema assay in mice. Compounds 2c and 2e were less ulcerogenic than ibuprofen in rats, when tested by ulcer index method. Compounds with electron attracting substituents such as 2c and 2e were found to be promising in terms of the ratio of efficacy and adverse effect. These compounds generally exhibited better activity than those of earlier series signifying fluorine substitution.

Anchoring of polyelectrolyte membrane containing chalcone group to electrode substrate by [2+2] cycloaddition and its humidity-sensing properties

New chalcone group-containing acrylic copolymers were prepared by the copolymerization of [3-(acrylamido) propyl]trimethyl ammonium chloride (APTAC), methyl methacrylate (MMA), and 4-methacryloyloxyphenyl styryl ketone (MPSK) for use as humidity-sensitive polyelectrolytes. The copolymers were self-crosslinkable terpolymers with different contents of APTAC /MMA/MPSK=70/27/3, 70/25/5, 70/23/7, and 70/20/10. Pretreatment of an alumina substrate with 4,4′-bis(3-triethoxysilyl)propoxy chalcone (BTSPC) containing an alkoxysilane-coupling agent was performed to attach the humidity-sensitive polyelectrolyte to it through covalent bonds. The sensors were irradiated with UV light, causing the electronically excited chalcone molecules to undergo a crosslinking reaction via [2π + 2π] addition. After soaking in water for 24 h, the resulting sensor using BTSPC showed water durability and a 42∼65% increase in resistance, corresponding to a 2.25∼2.98%RH decrease in relative humidity. The sensor showed good hysteresis (−0.2%RH), an acceptable response time (80 sec) and good stability at high temperatures and humidity.

Synthesis, Antibacterial and Analgesic Activities of 4‐[1‐Oxo‐3‐(substituted aryl)‐2‐propenyl]‐3‐(4‐methylphenyl) sydnones

A series of sydnone derivatives containing styryl ketone moiety, 4‐[1‐oxo‐3‐(substituted aryl)‐2‐propenyl]‐3‐(4‐methylphenyl)sydnones (6a‐i) has been synthesized and characterized by spectral data. The synthesized compounds have been screened for preliminary antibacterial activity by cup plate method and analgesic activity by the method of acetic acid induced writhing in mice. The chloro and nitro derivatives showed good antibacterial activity against both gram positive and gram negative bacteria while the chloro and furyl derivatives exhibited highest analgesic effect among the series.

Tetrafluoroboric Acid Adsorbed on Silica Gel as a Reusable Heterogeneous Dual-Purpose Catalyst for Conversion of Aldehydes/Ketones into Acetals/Ketals and Back Again

Aldehydes and ketones can be protected as acetals and ketals by treatment with trimethyl orthoformate (TMOF) or triethyl orthoformate (TEOF) under the catalytic influence of tetrafluorobo- ric acid adsorbed on silica gel (HBF4-SiO2). In the case of aldehydes or ketones with highly electrophilic carbonyl group, the reactions are carried out under solvent-free conditions. Aryl alkyl ketones, aryl styryl ketones, aldehydes with weakly electrophilic carbonyl groups, and aldehydes with substituents that can coordinate with the catalyst require the presence of the corresponding alcohol as sol- vent. For substrates that can be converted into acetals under neat conditions, the acetal formation takes place at a faster rate when the alcohol is used as the solvent. The catalyst can be recovered and re- used/recycled four times (after reactivation after each use) without any significant decrease in its catalytic efficiency. The parent alde- hydes/ketones are regenerated from the corresponding acetals/ ketals in high yields by the treatment with water-alcohol in the pres- ence of HBF4-SiO2 at room temperature for short times. Excellent selectivity was observed during inter- and intramolecular competi- tion studies involving carbonyl substrates with varying electronic and steric environments. Selective acetal formation of benzalde- hyde takes place in the presence of 4-(dimethylamino)benzalde- hyde, thiophene-2-carboxaldehyde, 1-naphthaldehyde, 9- anthraldehyde, or acetophenone, but 3-nitrobenzaldehyde under- goes selective acetal formation in preference to benzaldehyde. In the case of 4-acetylbenzaldehyde, exclusive acetal formation of the aldehyde carbonyl group occurs.

Selective Anodic Fluorination of Electrophilic Alkenes.

Abstract Anodic fluorination of some electrophilic alkenes (conjugated with electron-withdrawn groups), ethyl cinnamates, R C 6 H 4 CH CH CO 2 Et (R = H, CH 3 , CH 3 O, F and CF 3 ), cinnamonitrile, C 6 H 4 CH CH CN, phenyl stryryl ketone, and t -butyl styryl ketone using ammonium fluorides as the fluorine source and supporting electrolyte, in CH 2 Cl 2 as electrolytic solvent yields the expected vicinal difluoro compounds, as mixture of erythro and threo isomers. The anodic fluorination of phenyl 3,5-di- t -butyl-4-hydroxystyryl ketone yields two monofluoro compounds. A possible reaction mechanism is discussed.

Electrochemical Partial Fluorination of α,β‐Unsaturated Ketones.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Investigations on the Formation of 4-Aminobicyclo[2.2.2]-octanones

Benzylidene acetone reacts with thiocyanates derived from secondary amines in a one-pot reaction to give 4-aminobicyclo[2.2.2]octan-2-ones. The reaction mixture was investigated for the presence of possible intermediates using GC-MS. These intermediates – diketones and enamines – were prepared and exposed to the same reaction conditions to examine the reaction mechanism. The reaction of ethyl styryl ketone with thiocyanates of secondary amines yielded cyclohexanone derivatives instead of the expected bicyclo-octanones. Their structures were established by means of a single crystal structure analysis.

Selective anodic fluorination of electrophilic alkenes

Anodic fluorination of some electrophilic alkenes (conjugated with electron-withdrawn groups), ethyl cinnamates, R C 6H 4 CH CH CO 2Et (R = H, CH 3, CH 3O, F and CF 3), cinnamonitrile, C 6H 4 CH CH CN, phenyl stryryl ketone, and t-butyl styryl ketone using ammonium fluorides as the fluorine source and supporting electrolyte, in CH 2Cl 2 as electrolytic solvent yields the expected vicinal difluoro compounds, as mixture of erythro and threo isomers. The anodic fluorination of phenyl 3,5-di- t-butyl-4-hydroxystyryl ketone yields two monofluoro compounds. A possible reaction mechanism is discussed.

Inhibition of H(+)-ATPase-mediated proton pumping in Cryptococcus neoformans by a novel conjugated styryl ketone.

We investigated the in vitro susceptibility of clinical isolates of Cryptococcus neoformans to the novel conjugated styryl ketone NC1175 by broth microdilution. The MIC(90) and the MFC of NC1175 for C. neoformans were 1 and 2 mg/L, respectively. NC1175 at low concentrations (1-4 mg/L) completely inhibited the glucose-induced acidification of the external medium caused by the extrusion of intracellular protons mediated by the plasma membrane located H(+)-ATPase. These data suggest that NC1175 is a fungicidal agent for C. neoformans and its possible cellular target(s) include the H(+)-ATPase.