Phenacyl Bromide Research Articles

Synthesis and Evaluation of Thiazolyl pyrazolin-5-one Derivatives as Antioxidants for Egyptian Lubricating Oil.

The chemical structure of pyrazole-1-carbothioamide derivative 1 was modified through building a thiazole moiety to synthesize derivatives of thiazolyl pyrazolin-5-one. The reaction of 1 with phenacyl bromide furnished the conforming thiazolyl pyrazole derivative 2, which upon base-catalyzed reaction with benzyl isothiocyanate afforded thiazolyl 4-(benzylthiocarbamoyl)-2-pyrazolin-5-one derivative 3. The diazo-coupling reaction of 2 with diazotized 4-aminoacetophenone afforded the conforming thiazolyl 4-(p-acetylphenylhydrazono)-2-pyrazolin-5-one derivative 4. The synthesized thiazolyl pyrazolin-5-one derivatives were utilized as antioxidant additives for lubricating oil. The oxidation stability study revealed that the tested compounds showed good antioxidant activities. The efficiency of the tested antioxidant additives decreases according to the order: compound 2 > compound 4 > compound 3 > compound 1.

A simple synthesis of trifluoromethylated pyridinium azomethine ylides by three-component reaction between pyridines, phenacyl bromides, and N-aryltrifluoroacetimidoyl chlorides

A novel synthesis of trifluoromethylated pyridinium azomethine ylides by three-component reaction between pyridines, phenacyl bromides, and trifluoromethylated imidoyl chlorides in acetonitrile as solvent at room temperature without any catalyst is described. The FT-IR, 1H, 13C, 19F NMR spectral and elemental analysis confirm the structures of products. The synthesized azomethine ylides are easily purified by washing with diethyl ether and are stable even at high temperature. Heating of these ylides in refluxing acetonitrile, ethanol, or DMSO did not result in the intramolecular cyclization to imidazopyridine derivatives and only starting ylides were isolated.

Uniform copper nanoparticles as an inexpensive and efficient catalyst for synthesis of novel β-carbonyl-1, 2, 3-triazoles in water medium

Copper nanoparticles as an efficient, inexpensive catalyst were prepared via ball milling for synthesis of β-carbonyl 1, 2, 3-triazoles from azido alcohol by click reaction in water. An extensive range of raw materials such as sodium azide, phenacyl bromide, epichlorohydrin, and terminal alkynes were used. Complete reduction of CuO in presence of NaBH4 was done via ball milling with a ball-to-powder weight ratio of 50:1 under air atmosphere at room temperature. The final copper nanoparticles (Cu NPs) were characterized by SEM, EDX, XRD and FT-IR. The Cu NPs catalyzed one-pot three component synthesis of β-carbonyl 1, 2, 3-triazoles at room temperature with short reaction time and high product yields. The catalyst could be easily recovered and reused in several successive runs.

S-Alkylated 1,2,4-Triazoles Derivatives Synthesis, spectral analysis and cytotoxicity evaluation

This paper presents synthesis, characterization and cytotoxicity assessment of six S-alkylated 1,2,4-triazoles derivatives that were obtained by treatment of some 1,2,4-triazole-3-thiones containing in the molecule phenylsulfonylphenyl and propyl or 4-bromophenylsulfonylphenyl and 4-methoxyphenyl fragments with different alkylation agents (ethyl bromide, ethyl chloroacetate or phenacyl bromide) in basic media. The synthesized compounds were physico-chemically characterized and the IR, 1H-NMR, 13C-NMR spectra were consistent with the assigned structures. The cytotoxicity of S-alkylated derivatives was evaluated on Daphnia magna crustacean.

Multicomponent Efficient Synthesis of New [1,2,4]Triazolo[3,4]thiadiazines

A series of novel triazolo thiadiazines were synthesized by a simple, highly efficient, one‐pot pseudo four component approach involving the condensation of 4‐amino‐5‐hydrazinyl‐4H‐1,2,4‐triazole‐3‐thiol (1), aromatic aldehydes (2), and various phenacyl bromides (3) with good yields. The structures of compounds were confirmed by analytical and spectral (IR, 1H NMR, 13C NMR) data.

L‐Proline‐Functionalized Fe3O4 Nanoparticles as an Efficient Nanomagnetic Organocatalyst for Highly Stereoselective One‐Pot Two‐Step Tandem Synthesis of Substituted Cyclopropanes

AbstractIn this study, a series of highly stereoselective polysubstituted cyclopropane derivatives (trans‐2,3‐dihydro‐spiro[2‐aroyl‐3‐aryl‐cyclopropane]1,2‐indene‐1,3‐diones) were synthesized via a one‐pot two‐step tandem reaction starting from phenacyl bromide derivatives, 1,3‐indanedione and aromatic aldehydes in ethanol using 1,4‐diazabicyclo[2.2.2]octane (DABCO) as a co‐catalyst and Fe3O4\SiO2\propyltriethoxysilane\L‐proline as a nanomagnetic organocatalyst. This synthesized nanocatalyst was characterized by Fourier transforms infrared (FT‐IR) spectroscopy, energy dispersive X‐ray (EDX) analysis and scanning electron microscopy (SEM) images to confirm the formation of the nanocomposite. The catalyst can be easily recovered by simple magnetic decantation and their catalytic activity remains unaltered after ten consecutive cycles, making them environmentally‐friendly and widely applicable due to their efficiency, ease of handling and cost effectiveness.

Joining Microfluidics with Infrared Photodissociation: Online Monitoring of Isomeric Flow-Reaction Intermediates.

A cryogenic ion trap vibrational spectrometer is combined with a microfluidic chip reactor in a proof-of-principle experiment on the Hantzsch cyclization reaction forming 2-amino-4-phenyl thiazole from phenacyl bromide and thiourea. First, the composition of the reaction solution is characterized using electrospray-ionization mass spectrometry combined with two-color infrared photodissociation (IRPD) spectroscopy. The latter yields isomer-specific vibrational spectra of the reaction intermediates and products. A comparison to results from electronic structure calculations then allows for an unambiguous structural assignment and molecular-level insights into the reaction mechanism. Subsequently, we demonstrate that isomeric and isobaric ions can be selectively monitored online with low process time, i.e., using a single IRPD wavelength per isomer, as the chip reaction parameters are varied.

Synthesis of substituted pyrrolo[2,3-d]pyrimidines and pyrido[2,3-d]pyrimidines in the one-pot condensation of 2-thio-6-aminouracil, arylglyoxals and CH-acids

We have developed some available and effective methods for the synthesis of substituted pyrrolo[2,3-d]pyrimidines and 5,8-dihydropyrido[2,3-d]pyrimidines based on the three-component condensation of 6-amino-2-thiouracil with arylglyoxal hydrates and N,N-dimethylbarbituric acid or acyclic β-dicarbonyl compounds: acetylacetone (acetoacetic ester). It was shown that the optimal product yields were obtained by boiling the reagents in acetic acid. Thus, the synthesis of pyrrolo[2,3-d]pyrimidines took 15-20 minutes, while the precipitation of 5,8‑dihydropyrido[2,3-d]pyrimidines formed only after 2 hours. We proposed possible mechanisms for the formation of anelated pyrrole and pyridine rings. In both cases, the reaction includes the formation of an intermediate of α,β-unsaturated ketone with the participation of arylglyoxal and CH-acid (N,N-dimethylbarbituric or acetylacetone (acetoacetic ester)), nucleophilic addition of 6-aminothiouracil via an activated double bond, condensation of carbonyl and amino groups. The formation of the cycle takes place exclusively with the participation of the acetyl moiety, while the pyrrol one forms during the condensation of the aroyl moiety and the 6-amino group of thiouracil. A series of synthesized pyrrolo[2,3-d]pyrimidines was modified by alkylation. As it was expected, alkylation proceeds at the sulfur atom, that allowed a significant increase in the solubility of the obtained products. The reaction was carried out in DMF by stirring the initial reagents at 60ºC (reaction with methyl iodide) or boiling them (alkylation with phenacyl bromide), whereby S-methyl and S-phenacyl derivatives of pyrrolo[2,3-d]pyrimidines were obtained. The spectral data of 1H NMR showed that S-methylation products form solvates with DMF as 1:1. The synthesized compounds can become the basis to create small libraries of anelated pyrimidines with improved antiviral activity profile.

New insight into the chemistry of selenoureas: synthesis and single crystal structural study of diverse derivatives

A series of new heteroatom derivatives of N-acylselenoureas was obtained through the reaction of KSeCN with acyl chloride and primary amines, followed by the cyclisation reaction with phenacyl bromides.

Tandem transfer hydrogenation–epoxidation of ketone substrates catalysed by alkene-tethered Ru(ii)–NHC complexes

Eight novel alkene-tethered Ru(ii)–NHC complexes were employed as catalysts in tandem transfer hydrogenation–epoxidation reactions using phenacyl bromide derivatives as substrates.

Covalent organic framework as an efficient, metal-free, heterogeneous photocatalyst for organic transformations under visible light

Visible-light active, heterogeneous, and organic photocatalysts exhibit a more sustainable and environmentally friendly alternative to classical metal-based catalysts. Two-dimensional covalent organic frameworks (2D-COFs) with permanent porosity, columnar π-arrays and excellent stability, that can become an excellent platform for heterogeneous photocatalysis of organic transformations. Here we report a predesigned imine-based COF with electron donor and acceptor structure. And new framework possesses large surface area, high crystallinity, outstanding stability and broad absorption range in the visible-light region as well as good photoelectric response characteristics. Importantly, it was found to be a highly effective heterogeneous photocatalyst for reductive dehalogenation of phenacyl bromide derivatives and α-alkylation of aldehydes under irradiation of visible-light. In addition, the COF gave good recyclability and could be reused after a simple separation manipulation. The current present still reveals a great prospect for 2D-COFs as metal-free, heterogeneous photocatalysts for organic transformations.

Sulfone-modified chitosan as selective adsorbent for the extraction of toxic Hg(II) metal ions

In this study, a new category of sulfone-modified chitosan derivatives as surface-selective adsorbents for the extraction of toxic Hg(II) metal has been synthesized in good yield. Sulfone-modified chitosan/5–20 based on variable loading of the corresponding phenacyl bromide (5, 10, 15, and 20% with respect to the original weight of the pure chitosan) was synthesized. The β-ketosulfone derivative, namely 1–(4-bromophenyl)-2-(phenylsulfonyl)ethanone, was first prepared by treatment of the corresponding phenacyl bromide with a sufficient amount of sodium benzene sulfinate; its chemical structure was confirmed by spectral analyses, including Fourier transform infrared spectroscopy, 1H-NMR, 13C-NMR, and mass spectrometry. Then, sulfone-modified chitosan/5–20 derivatives were synthesized by the interaction of chitosan with a freshly prepared p-bromo-β-ketosulfone derivative in a mildly acidic aqueous solution using the solution-blending technique. Sulfone-modified chitosan/5–20 derivatives were identified and characterized using common characterization techniques, including Fourier transform infrared spectroscopy, field-emission scanning electron microscope, powder X-ray diffraction, and thermal behaviour. A strong interaction was displayed between chitosan and its corresponding β-ketosulfones in powder X-ray diffraction, which was confirmed by significant 2θ shifts. Sulfone-modified chitosan/5–20 derivatives were detected as catalysts, which efficiently increased the thermal decomposition of pure chitosan. More particularly, the efficiency of sulfone-modified chitosan/5–20 derivatives for Hg(II), Pb(II), Ni(II), Al(III), Sr(II), Cr(III), Fe(III), Zn(II), and Mn(II) detection and adsorption was also investigated using inductively coupled plasma optical emission spectrometry. The sulfone-modified chitosan/5 derivative exhibited the highest adsorption efficiency. The most effective quantitative adsorption onto the sulfone-modified chitosan/5 surface was detected at pH = 2. In addition to that, the adsorption isotherm showed that the adsorption capacity of sulfone-modified chitosan/5 for Hg(II) was 122.47 mg g−1 and that its adsorption isotherm was in agreement with the Langmuir adsorption isotherm.

An efficient one-pot expeditious synthesis of 3-phenyl-1-(6-phenyl-7H-[1,2,4] triazolo[3,4-b] [1,3,4] thiadiazin-3-yl)-1H-pyrazol-5-amines via multicomponent approach

An efficient synthesis of 3-phenyl-1-(6-phenyl-7H-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazin-3-yl)-1H-pyrazol-5-amines was accomplished by a simple, atom-economical, and multicomponent approach. Reaction of 4-amino-5-hydrazinyl-4H-1,2,4-triazole-3-thiol with various phenacyl bromides and benzoylacetonitriles in ethanol and catalytic amount of acetic acid afforded the titled compounds. The structures of newly synthesized compounds were confirmed by their analytical and spectral (IR, 1H-NMR, 13C-NMR, and Mass) data.

Design, Synthesis, and Structural Elucidation of New Pyridine and Thienopyridine Derivatives

New series of 3‐cyanopyridine scaffolds were prepared from the reaction of 3‐(4‐bromophenyl)‐1‐(3,4‐dimethoxyphenyl)prop‐2‐en‐1‐one with active nitriles, including malononitrile and 2‐cyanothioacetamide. The newly prepared 6‐(4‐bromophenyl)‐4‐(3,4‐dimethoxyphenyl)‐2‐thioxo‐1,2‐dihydropyridine‐3‐carbonitrile was used as a scaffold for the preparation of new series of condensed thienopyridines by its reactions with active halo compounds, namely, ethyl chloroacetate, chloroacetonitrile, phenacyl bromide, chloroacetone, and 2‐chloro‐N‐arylacetamide. The structures of the synthesized compounds were elucidated by the elemental analysis, spectral data and chemically by their preparations with other pathways.

A facile one-pot expeditious synthesis of triazolothiadiazines and anticancer activity

A novel, one-pot, multicomponent synthesis of triazolothiadiazine derivatives have been achieved starting from 4-amino-4H-1,2,4-triazole-3,5-dithiol and variously substituted phenacyl bromides. The synthesis involves the simultaneous formation of two C–S and one C = N bond. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, and mass spectral data. The advantages of this method are good yields, high purity, shorter reaction times and simple purification technique. The synthesized target compounds were screened for their in vitro anticancer activity at concentration 10−5 M against 60 cancer cell lines. Among all the compounds, 1-(4-Fluorophenyl)-2-((6-(4-fluorophenyl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl) thio)ethanone (4d), 1-(4-Bromophenyl)-2-((6-(4-bromophenyl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)thio) ethanone (4f), and 2-((6-(4-Chlorophenyl)-7H-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazin-3-yl)thio)-1-(4-fluorophenyl)ethanone (4l) exhibited significant activity in terms of growth percent against renal cancer OU-31 cell line with 47.42%, 46.76%, 48.14%. The compound 2-((6-(4-Chlorophenyl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)thio)-1-(4-fluorophenyl) ethanone (4l) also exhibited significant activity on leukemia MOLT-4 cell line with 49.82%.

Disubstituted Aminoanthraquinone-Based Photoinitiators for Free Radical Polymerization and Fast 3D Printing under Visible Light

The development of highly efficient and rapid photoinitiating systems for free radical photopolymerization under the irradiation of visible light has attracted increasing attention due to their widespread potential applications in, for example, 3D printing or dental polymers. Unfortunately, currently available visible-light-sensitive photoinitiators are not efficient enough for 3D printing applications suffering from low printing speeds. Here we describe a series of photoinitiating systems consisting of disubstituted aminoanthraquinone derivatives (i.e., 1-amino-4-hydroxyanthraquinone, 1,4-diaminoanthraquinone, and 1,5-diaminoanthraquinone) and various additives (e.g., tertiary amine and phenacyl bromide) toward the free radical photopolymerization of various acrylate monomers (such as commercial 3D resin) under the irradiation of blue to red LEDs. It is shown that the type and position of substituents of the aminoanthraquinone derivative can significantly affect its photoinitiation properties. The most e...

Synthesis, Characterization, and Anticancer Activity of Some Thiazole and Imidazolidine Derivatives Containing Pyridine Moiety

5-Phenyl-2-[(6-acetylpyridine-2-ylethylidene)hydrazino]thiazole 4 and 1-[(6-acetylpyrid-ine-2-ylethylidene)amino]-2-thioxoimidazolidine-4-one 6 are synthesized by cyclization of 1-[1-(6-acetylpyridin-2- yl)ethylidene]thiosemicarbazide 2 with phenacyl(ω)bromide or ethyl chloroacetate in the presence of fused sodium acetate. Reaction of compounds 2, 4, and 6 with acetic anhydride gives N-triacetyl derivative 3 and N-acetyl derivatives 5 and 7. Treatment of compound 6 with 4-methoxy benzaldehyde yields the corresponding carbanol derivative 8. Structures of the synthesized heterocyclic compounds are characterized by EI-MS and NMR spectroscopy. Antitumor activity of compounds 4, 6, 8, and 9 is evaluated against human breast carcinoma cell line (MCF-7).

Efficient One-Pot, Two-Component Modular Synthesis of 3,5-Disubstituted Pyrazoles.

The pyrazole scaffold is one of the most prevalent and important tool in medicinal chemistry. Here, we report a method for preparing 3,5-diarylpyrazoles in good to excellent yield by reacting hydrazones of aryl aldehydes with substituted acetophenones in ethanol in the presence of dimethyl sulfoxide/cat. I2/cat. HCl. The reverse process, reacting hydrazones of substituted acetophenones with aryl aldehydes under the same conditions, also provides 3,5-diarylpyrazoles in good to excellent yields. Reaction of hydrazones of aldehydes with 2′-aryloxy ketones in the presence of cat. HCl in ethanol and the catalyst-free reaction of phenacyl bromides with hydrazones of aldehydes in ethanol also gave good to excellent yields of 3,5-diarylpyrazoles.

Synthesis, biological evaluation, molecular docking and in silico ADME studies of phenacyl esters of N-Phthaloyl amino acids as pancreatic lipase inhibitors

In continuation of our previous study, a series of phenacyl esters of N-phthaloyl amino acids were synthesized and screened for their in vitro pancreatic lipase inhibitory activity. N-phthloylation of amino acids and subsequent esterification with different phenacyl bromides in presence of N,N-Dimethylformamide (DMF) afforded the corresponding phenacyl esters in quantitative yields. The synthesized compounds were found to have potent in vitro pancreatic lipase inhibitory activity in 0.9–2.5 μM range. The most active compound 2‐(4‐bromophenyl)‐2‐oxoethyl 3‐(1,3‐dioxo‐2,3‐ dihydro‐1H‐isoindol‐2‐yl) propanoate (4g) displayed very good pancreatic lipase inhibitory activity with the IC50 value 0.9 μM. To understand the enzyme inhibition and to ensure the lead likeness, in silico docking and ADME studies were carried on title compounds. The in vitro pancreatic lipase inhibitory activities and in silico studies suggested that this N-phthaloyl phenacyl ester analogues could be a potential lead and may be taken to the next level of antiobesity drug development.

Conventional and Microwave Synthesis of some new pyridine derivatives and evaluation their antimicrobial and cytotoxic activities.

The newly synthesized compounds based on 2-amino-6-(2,4-dimethoxyphenyl)-4-(4-methoxyphenyl)nicotinonitrile 1. The reactivity of pyridine derivative 1 was studied towards different reagents by its reaction with malononitrile, 2-(4-chlorobenzylidene)malononitrile, ethyl cyanoacetate, cyano acetic acid, m-nitro benzaldehyde, sodium azide, formamide, acetic anhydride and/or acetic anhydride/H2SO4 to give compounds 2-5,7, 10-13, respectively. The reaction of 5 with acetyl acetone gave the bipyridine derivative 6, while reaction of compound 7 with chloroacetyl chloride and phenacyl bromide gave the azetidinone derivatives 8 and 9. The formimidate 14 were obtained via reaction of compound 1 with triethylorthoformate, while reaction of 14 with phenylene diamine and/or acetamide gave the formimidamide and pyridopyrimidine derivatives 15 and 16 respectively. Compound 1 was also allowed to react with urea, thiourea, phthalic anhydride, succinic anhydride, benzoyl chloride, chloroacetonitrile, chloroacetyl chloride, p-toluenesulfonylchloride and ethyl bromoacetate to give compounds 17a,b - 24. Reaction of compound 1 with dichloro reagents in 1:1 ratio gave the bicyclic derivatives 25a–c, while its reaction with oxalyl chloride, dichloro and tetrachlorobenzoquinone derivatives, and/or dichloronaphthoquinone gave the imidazopyridine derivatives 26-29. Reaction of compound 29 with o-phenylenediamine in 1:2 ratio afforded the di-condenesed product 30 while, reaction of compound 1 with dichlororeagents in 1:2 ratio gave the polyalkyl derivatives 31a-b. The newly synthesized compounds were characterized by IR, 1H-NMR, 13C-NMR and mass spectra. On the other hand the antimicrobial and anticancer activities of some of the newly synthesized compounds was studied and evaluated.