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An efficient, simple, and greener method has been described for the synthesis of 3-(2-chlorobenzyl)-6-(substituted phenyl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines by using microwave irradiations. The one-pot reaction between 4-amino-5-(2-chlorobenzyl)-4H-1,2,4-triazole-3-thiol and various phenacyl bromide in the presence of reusable catalyst DABCO and EtOH solvents to give the desired products. We have discovered different organic compounds as antimicrobial agents and study for their structure-activity relationships (SAR). The antimicrobial screening shows moderate activities against used microbes.

Herein, a convenient and efficient synthesis of 7-benzoyl-6-(aryl)-6,7-dihydro-5H-furo[2,3-d]thiazolo[3,2-a]pyrimidin-5-one derivatives was achieved from the reaction of isoquinolinium N-ylides, aromatic aldehydes, and heterocyclic 1,3-dicarbonyl compounds via one-pot three-component diastereoselective domino reaction in good-to-excellent yields. The advantages of this protocol are easily available starting materials, operational simplicity, and avoidance of hazardous organic solvents and catalyst. The synthesized products were characterized by IR, 1H NMR, 13C NMR and mass spectra. Additionally, the conclusive structure of target compounds was confirmed by X-Ray diffraction analysis.

A metal-free, simultaneous triple C-C coupling cyclization reaction between phenacyl bromides and indoles is discovered in a highly regioselective fashion to furnish 3,5-diarylcarbazoles. DMAP is utilized as the only reagent for the unusual and rapid cyclization reaction to furnish all new carbazole compounds through installation of a great diversity of substituents. A plausible radical mechanism for the new reaction is predicted by conducting various control experiments, competitive reactions, furoindole formation, and ESI-MS analyses of the ongoing cyclization reaction.

A new set of thiazolyl-pyrazolines 3a–l was prepared by cyclization of carbothioamides 2a–g with phenacyl bromide and/or 4-bromo phenacyl bromide. The new chemical entities were tested for their antimicrobial properties, while none of the tested samples showed promising activity. The derivatives 2a–c demonstrated moderate potency against Staphylococcus aureus having the potential to be optimized into promising antimicrobial candidates. In addition to elemental analyses, the structural elucidation of the new analogues was carried out via IR, 1H NMR, 13C NMR as well as mass spectral data.

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. Reac...

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...

International audience; Three monoamino-substituted anthraquinone derivatives (AAQs), that is, 1-aminoanthraquinone (AAQ), 1-(methylamino)anthraquinone (MAAQ), and 1-(benzamido)anthraquinone (BAAQ), incorporated with various additives [e.g., triethanolamine (TEAOH) and phenacyl bromide (PhC(═O)CH2Br)] are investigated for their roles as photoinitiating systems of free radical photopolymerization of (meth)acrylate monomers upon the exposure to UV to green LEDs. The AAQs-based photoinitiating systems, AAQ/TEAOH/PhC(═O)CH2Br and BAAQ/TEAOH/PhC(═O)CH2Br photoinitiators exhibit the highest efficiency for the free radical photopolymerization of DPGDA under the irradiation of blue LED and UV LED, respectively, which is consistent with the extent of overlap between their absorption spectra and the emission spectra of the LEDs. AAQ/TEAOH/PhC(═O)CH2Br photoinitiator can also initiate the free radical photopolymerization of different (meth)acrylate monomers, with an efficiency dependent on the chemical structures of these monomers.

An easy access to a series of N-phenylmorpholine derivatives linked with thiazole or formazan moieties were achieved using simple experimental procedure under conventional and microwaves irradiation conditions. The reaction of 2-(N-phenylmorpholine)ethylidene)hydrazine-1-carbothioamide derivatives and [1-(4-morpholin-4-yl-phenyl)-ethylidene]-hydrazine with a variety of hydrazonoyl chlorides or phenacyl bromide derivatives afforded the corresponding thiazoles or N-substitutedhydrazino-derivatives linked to N-phenylmorpholine moiety in good to excellent yields. The structures of the newly synthesized compounds were fully emphasized and characterized by spectroscopic as well as elemental analyses. The mode of binding of some selected compounds with SS-DNA was evaluated using UV–Vis absorption, and viscosity measurements. The results showed intercalation binding mode of most of the tested compounds. Both antimicrobial and anti-cancer activities have been studied for some selected compounds from synthetic derivatives. Their results showed a remarkable efficacy for some derivatives against both examined microbes and cancer cells.

The highly substituted 1,2,4-trisubtituted imidazole was regioselectively synthesized via base mediated domino reaction of amidine scaffold with phenacyl bromide followed by in situ N-alkylation of imidazole. The reaction conditions were optimized in order to access three phenomenon (neutralization, condensation, and N-alkylation) in a single pot. A mechanism for the formation of N–H imidazole and its subsequent N-alkylation is depicted by isolation of reaction of intermediates. Electron donating group facilitate N-alkylation, whereas no N-alkylation was observed in the presence of electron withdrawing (NO2) group. The synthesized compounds and reaction intermediate were characterized using NMR, FTIR, and HRMS. Exact orientation of various aromatic rings in regioselective N-alkylated product was confirmed using single crystal X-ray analysis.

This Article deals with the stepwise synthesis and spectroscopic characterization of some new azo benzofuran derivatives, started from the diazotization of substituted aniline coupled with 2-hydroxy benzaldehyde. On reacting of the azo of 2-hydroxy benzaldehyde with p-bromo phenacyl bromide, the benzofuran (3a-g) are obtained. The structure of the new benzofuran derivatives have been characterized by using FT-IR, 1H-NMR,13C-NMR and DEPT-135 NMR. The biological activity of some new synthesized compound was obtained by vitro anti oxidant and anti microbial activity with both Staphylococcus aureus and Escherichia coli .The results showed that the new benzofurans have mild anti oxidant activity compared to the standard ascorbic acid.

Thirty benzofuran-2-yl(phenyl)methanones 1–30 were synthesized and characterized their structures by spectroscopic techniques. Substituted phenacyl bromide and different derivatives of 2-hydroxy-benzaldehyde treated in the presence of anhydrous K2CO3 in acetonitrile at room temperature to afford the desired benzofurans 1–30. All compounds were screened for their in vitro α-amylase inhibitory and radical scavenging (DPPH and ABTS) activities. Results revealed that para substituted compounds were found to be more active than the others with IC50 values ranges for α-amylase inhibition (IC50 = 18.04–48.33 µM), DPPH (IC50 = 16.04–32.33 µM) and ABTS (IC50 = 16.99–33.01 µM) radical scavenging activities. Activities results were compared with the standards acarbose (IC50 = 16.08 ± 0.07 µM) for α-amylase, ascorbic acid (IC50 = 15.08 ± 0.03 and 15.09 ± 0.17 µM) for DPPH and ABTS radical scavenging activities, respectively. Kinetic studies predicted that all compounds followed non-competitive mechanism of inhibition. Molecular docking results showed good protein–ligand interactions profile against the corresponding target. To the best of our knowledge, out of thirty molecules, ten compounds 18–20, 22, and 25–30 were structurally new.

Phenacyl bromides are used as a building blocks in synthetic organic chemistry, which serves as a key model for the development of various biologically important heterocyclic compounds and other in...

A greener approach for the synthesis of 4-oxo-4,5,6,7-tetrahydro indole derivatives has been achieved through Wang-OSO3H-mediated three-component reaction involving dimedone, phenacyl bromide, and ...

Effective methodology that activates selectively either end of a carbon–carbon triple bond requires key challenge of differentiating between the multitude of C C bonds present in complex organic molecule. The synthetic strategy exploited the electronic biases within the substrate and successfully achieved site–selective [bmIm]OH catalyzed C C bond functionalization under mild reaction conditions. This resulted in C-2-selective addition of phenacyl bromide on p-substituted phenyl acetylene and C-1 selective addition on the o-substituted phenyl acetylene leading to C C bond formation. The reaction proceeded smoothly with excellent yield under ambient conditions. This report demonstrates the progress on the catalytic activity of recyclable [bmIm]OH for selective C C bond formation.

A series of novel 6-functionalized-5-amino-3-methyl-1-phenyl-1H-furo[3,2-e]pyrazolo[3,4-b]pyrazines (4a–c) was synthesized by the reaction of 3-methyl-6-oxo-1-phenyl-6,7-dihydro-1H-pyrazolo[3,4-b]pyrazine-5-carbonitrile (2) with α-halocarbonyl compounds such as: diethyl 2-bromomalonate, phenacyl bromide and chloroacetone. Cyclocondensation of the amino benzoyl 4b with diethyl malonate yielded the oxopyridine carboxylate derivative 5. Also, the starting intermediate amino ester compound 4a was allowed to react with ethanol amine to afford the hydroxyethyl caboxamide derivative 6. Furthermore, hydrazinolysis of the amino ester 4a afforded the corresponding amino carbohydrazide 7 which was used as a versatile precursor for synthesis of other heterocyclic compounds attached or fused to the furopyrazolopyrazine moiety. The chemical structures of the newly synthesized compounds were confirmed on the basis of elemental and spectral analyses containing FT-IR, 1H NMR, 13C NMR, and mass spectrometry hoping ...

The multicomponent reaction between isatin, amino acid, but-2-ynedioates, and phenacyl bromide has been developed using microwave irradiation under catalyst and base-free conditions in aqueous medium. This synthetic protocol is useful for the synthesis of various functionalized spirooxindole derivatives. This MCR exhibits a broad substrate scope with excellent yields and shorter reaction time. Additionally the synthesized spirooxindole derivatives were evaluated for their anticancer activity against three human cancer cell lines: MCF-7 (breast), A549 (lung), and HeLa cervical. Most of the compounds showed moderate to potent cytotoxic activity against the tested cell lines.

1-(3-Chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazole-4-carbaldehyde was used in preparation of (E)-1-{[1-(3-chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazol-4-yl]methylene}thiosemicarbazide. Its following reaction with ethyl bromoacetate, diethyl 2-bromomalonate, phenacyl bromide, and maleic anhydride gave pyrazolyl pharmacophore linked thiazole, thiazoline and thiazolidinone-5-carboxylic acid derivatives.

In the present manuscript, a series of steroidal thiazole derivatives (4–6, 8) have been synthesized in efficient manner by one step reaction methodology employing microwave irradiation. The synthesis involves the reaction of steroidal ketones (1–3, 7) with thiosemicarbazide and phenacyl bromide. Structural assignment of the products was confirmed on the basis of IR, 1H NMR, 13C NMR, MS and analytical data. The synthesized compounds were screened for in vitro antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. In addition, the products 4–6, 8 were also tested for pBR322 DNA cleavage activity, genotoxicity, reactive oxygen species (ROS) production and RBC hemolysis. Molecular docking analysis was carried out to validate the specific binding mode of the newly synthesized compounds into the active site of DNA. Docking showed formation of more stable complexes of compounds 4 and 8 with the free binding energies − 8.1 and − 8 kcal/mol, respectively. Hence, it could be suggested that the steroidal compounds bearing a core thiazole scaffold would be a potent biological agent.

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.

Karakurt, Tuncay/0000-0001-6944-9883; TAHTACI, HAKAN/0000-0002-1557-6315 WOS: 000471778600031 In this study, we synthesized new imidazo[2,1-b][1,3,4]thiadiazole derivatives containing benzothiazole group. To this end, we firstly obtained the benzo[d]thiazol-2-ylthio/oxy acetonitrile compounds (3a,b), the starting materials, in high yields (82% and 87%, respectively). Then, we synthesized the 2-amino-1,3,4-thiadiazole derivatives (4a,b) from the reaction of these nitrile derivatives (3a,b) with thio-semicarbazide in trifluoroacetic acid (TFA) (in yields of 83% and 84%). Finally, we synthesized the imidazo [2,1-b][1,3,4]thiadiazole derivatives (5-24) containing benzothiazole group, which are the target compounds, from reactions of 2-amino-1,3,4-thiadiazole derivatives (4a,b) with phenacyl bromide derivatives (in yields of 53%-73%). All of the compounds synthesized were characterized with H-1 NMR, C-13 NMR, FT-IR, elemental analysis, and mass spectroscopy. Antileishmanial and antibacterial activity tests were applied to the compounds synthesized in the study. It was observed that compound 8 had the highest antileishmanial activity (MIC = 10 000 mu g/mL). Also, compounds 7 and 17 were found to be effective at the highest concentration studied (MIC = 20 000 mu g/mL). In terms of antibacterial activity, compounds 4b and 7 were found to be the most effective compounds against Escherichia coli (MIC = 625 mu g/mL). Theoretical calculations were performed to support the experimental results. To this end, we performed Molecular Docking studies to determine whether or not the compounds (4a, 4b, 7 and 13) optimized with Gaussian09 using the DET/B3LYP/6-31G(d,p) theory, which is a quantum chemical calculation, could be an inhibitor agent for the 2eg7 Escherichia coli protein structure. Also, we investigated the relationship between the calculated HOMO values of these four ligands and docking studies. (C) 2019 Elsevier B.V. All rights reserved. Karabuk UniversityKarabuk University [KBUBAP-17-YL-038] The financial support by the Karabuk University (Project ID Number: KBUBAP-17-YL-038) is gratefully acknowledged.

Bio-active steroidal imidazoles 7–9 were synthesised by reacting steroidal thiosemicarbazones 4–6 with phenacyl bromide. After characterisation by spectral and analytical data, the interaction of compounds 7–9 with DNA were carried out by UV-vis, luminescence spectroscopy and gel electrophoresis. The compounds bind with DNA preferentially through electrostatic and hydrophobic interactions with K b; 3.14 × 104, 6.27 × 104 and 5.17 × 104 M−1, respectively indicating higher binding affinity of compound 8 towards DNA. Gel electrophoresis depicted the concentration dependent cleavage activity of compound 8 with supercoiled pBR322. The docking study revealed the minor groove binding of compounds with DNA and intercalation between the nucleotide base pairs is due to imidazole moiety. In Dimethyl thiazolyl diphenyl tetrazolium bromide assay, compounds 7 and 8 showed promising activity against different human cancer cells especially against A545, HepG2 and MCF7 cells. The uptake of compounds by HepG2, MCF7 and A549 cells was studied by confocal microscopy. The Genotoxic nature of compounds 7 and 8 was studied by the comet assay while as the relative expressions of apoptotic markers of A545 cells after interacting with steroidal imidazoles was studied by western blotting analysis.

Thiazoles and their derivatives have attracted continuing interest in both pharmaceutical and agrochemical industries and shows significant importance for the discovery of potent bioactive agents due to their various biological activities. The present study reports the synthesis of novel 2-{2-[(6-methoxynaphthalen-2-yl) methylidene] hydrazinyl}4-(aryl)-1, 3-thiazole (5a-5j) which was synthesized by acid hydrolysis of 6-methoxynaphthalene-2carbaldehyde (1) and hydrazinecarbothioamide (2) which was refluxed for around 10 hours using alcohol as solvent, to yield (2E)-2-[(6-methoxynaphthalen-2-yl) methylidene] hydrazinecarbothioamide (Thiosemicarbozone) (3). The compound (3) was then condensed with different substituted phenacyl bromide (4) at 90 o C for 8-9 hours .The structures of newly synthesized compounds were characterized by IR, 1 H-NMR, 13 C -NMR and mass spectroscopic studies, few of the synthesized compounds showed moderate anti-TB activities and compounds (5d) showed moderate activity against M.tuberculosis (H37 RV Strain).Among the compounds screened for antibacterial activity (5c), (5e), (5g) and (5h) showed excellent antibacterial activity.

Pyridazines with amino groups positioned para to each aromatic ring nitrogen and fixed in six-membered rings were prepared. The representative symmetric amino N-Et derivative was found to slightly exceed DMAP in catalytic activity in the acetylation reaction of a tertiary alcohol in C6D6. Nucleophilicity eclipsing that of DMAP was established in competitive reactions using phenacyl bromide as the electrophile, and the unsymmetric N-Et derivative was revealed to have even higher nucleophilicity.

An efficient one-pot multicomponent synthesis of 3-(2-(1H-indol-3-yl)ethyl)-4-hydroxy-4-arylthiazolidine-2-thione and 3-(2-(1H-indol-3-yl)ethyl)-4-arylthiazole-2(3H)-thione has been developed from a multicomponent reaction of tryptamine, carbon disulfide and phenacyl bromide. This protocol has an advantage such as operational simplicity, short reaction time, and affording good to excellent yields.

An efficient method for the synthesis of 1-aryl-6,6-dimethyl-2-phenyl-6,7-dihydro-1 H -indol-4(5 H )-ones is achieved in two steps, using a three-component reaction of phenacyl bromide, dimedone and aniline derivatives in water-ethanol (1:1) under reflux conditions.

A new series of hydrazino thiazolyl-2-azetidinone 4(a-i) derivatives were synthesized efficiently using benzylidene hydrazinyl thiazole derivatives 3(a-i). The precursors, benzylidene hydrazinyl thiazoles were prepared by reacting 4- fluoro phenacyl bromide with thiosemicarbazones 2(a-i). All the structures of the synthesized compounds were ascertained by IR, NMR and mass spectral analysis

A new series of N- and S-alkylated products of 3-aryl-1H,3H-quinazolin-2,4-dione and 3-aryl-2-mercapto-3H-quinazolin-4-one, respectively, were prepared in good yields via efficient nucleophilic substitution reaction of the SH and NH substrates with methyl iodide, ethyl bromoacetate, allyl bromide, propagyl bromide, 2-bromoethanol, 1,3-dibromopropane or phenacyl bromide in DMF as a solvent and anhydrous potassium carbonate. The quinazolin-2,4-dione favored the N-alkylation while the 2-mercapto-3H-quinazolin-4-one goes via the S-alkylation. DFT reactivity studies showed that the former have the N-site with higher nucleophilicity compared to the O-site. In contrast, the S-site is the more nucleophilic centre than the N-atom of the latter. The structures of the synthesized products have been established on the basis of their melting point (m.p), IR and 1HNMR data. The molecular structures of the products were calculated using the DFT B3LYP/6-311G(d,p) method. The electronic and spectroscopic properties (Uv–Vis and NMR spectra) were calculated using the same level of theory. The chemical reactivity descriptors that could help to understand the biological activity of the products are also predicted.

3-Methyl-1-thiocarbamoyl-2-pyrazolin-5-one has been utilized as a core for the synthesis of some 1-(thiazol-2-yl)-pyrazolin-5-one derivatives through diazo-coupling reaction and/or Knoevenagel condensation followed by heterocyclization with some α-halogenated reagents such as bromoacetone, phenacyl bromide, and ethyl bromoacetate. Base prompted addition of the core compound to an equimolar amount of phenyl isothiocyanate furnished 3-methyl-4-phenylthiocarbamoyl-1-thiocarbamoyl-2-pyrazolin-5-one which undergoes heterocyclization with α-halogenated reagents at the more reactive phenylthiocarbamoyl moiety to afford the corresponding 4-(thiazol-2-yl)-1-thiocarbamoyl-2-pyrazolin-5-ones. The new synthesized thiazolyl–pyrazolone compounds were evaluated for their potential antioxidant activity by using (ABTS Radical Cation Decolorization Assay).

5-Phenyl-2-[(3,4,5-trimethoxybenzylidene)hydrazino]-thiazole and 3-[(3,4,5-trimethoxybenzylidene)amino]-4-oxoimidazolidin-2-thione were prepared by cyclization of 1-[(3,4,5-trimethoxybenzyliden)amino]-thiourea with phenacyl bromide and ethyl chloroacetate in the presence of fused sodium acetate. Acetylation of the synthesized compounds with acetic anhydride gave corresponding N-acetyl derivatives. Condensation of the synthesized thione with aromatic aldehydes yielded two 3-substituted 5-arylidene-4oxo-imidazolidin-2-thiones. Acetylation of the latter compounds with acetic anhydride afforded the corresponding N-acetyl-4-oxo-imidazolidin-2-thiones. Some of the synthesized compounds exhibited antimicrobial activity. The cytotoxic activity of the prepared thiazole and imidazolidin-2-thione derivatives was studied on several tumor cell lines.

This article describes the synthesis of some novel coumarin compounds to use as acid dyes by using compounds 1 - 4 as starting materials, which were prepared by interaction of 2-hydroxybenzaldehyde with ethyl 3-oxobutanoate, diethylmalonate, 4-nitrobenzenediazonium chloride and 4-sulfobenzenediazonium chloride, respectively. Compound 1 reacted with bromine and 2-cyanoacetohydrazide to give phenacyl bromide derivative 5 and 2-cyanoacetohydrazone derivative 6, respectively. Coupling of compound 6 with equimolar amount of 2-sulfo-4-((4-sulfophenyl) diazenyl)benzenediazonium chloride gave coumarin acid dye 8. Phenacyl bromide derivative 5 re-acted with potassium cyanide in refluxing ethanol to produce compound 7, which on coupling with equimolar amount of 8-hydroxy-6-sulfonaphthalene-2-diazonium chloride and 8-hydroxy-3,6-disulfonaphthalene-1-diazonium chloride gave coumarin acid dyes 9 and 10, respectively. Interaction of compound 2 with 2-amino-5-((4-sulfophenyl)diazenyl)benzenesulfonic acid, benzene-1,4-diamine and 3,3’-dimethoxy-[1,1’-biphenyl]-4,4’-diamine in refluxing ethanol afforded compounds 11, 12 and 14, respectively. Diazonium sulphate of compounds 12 and 14 coupling with 4-amino-5-hydroxynaphthalene-2,7-disulfonic acid gave compounds 13 and 15, respectively. Cyclocondensation of compound 3 with ethyl 3-oxobutanoate, diethyl malonate and malononitrile afforded derivatives of 3-acetyl-2H-chromen-2-one 16, ethyl 2-oxo-2H-chromene-3-carboxylate 17 and 2-imino-2H-chromene-3-carbonitrile 18, respectively. Reaction of sodium benzenesulfonate derivative 4 with ethyl 3-oxobutanoate and hydrazine hydrate gave compounds 19 and 20, respectively. The structures of the newly synthesized compounds were confirmed by elemental analysis, UV/ VIS, IR, 1H NMR and Ms spectral data. The suitability of the prepared dyestuffs for dyeing of wool and silk fabrics has been investigated. The dyed fabric shows good light fastness, very good rubbing, perspiration, washing and excellent sublimation fastness. These dyes have been color shade from blue to violet with very good depth and levelness on fabrics. The dye bath exhaustion and fixation on fabric has been found to be very good.

A facile synthesis of tricyclic skeleton of alkaloid 261C has been achieved by a double [3+2] cycloaddition of p-methoxypyridinium phenacyl bromide and maleimides with high diastereoselectivity. The initial Hammett analysis suggested that the most stable resonance form of pyridinium ylide is the one, the negative charge of which is widely dispersed in the pyridine ring.

Two naphthoquinone derivatives, i.e. 5-hydroxy-1,4-naphthoquinone (5HNQ) and 2-hydroxy-1,4-naphthoquinone (2HNQ), combined with different additives such as diphenyliodonium hexafluorophosphate (Iod), N-vinylcarbazole (NVK), phenacyl bromide (R-Br), N-phenyl glycine (NPG) and ethyl 4-dimethylamino benzoate (EDB), are investigated as photoinitiating systems (PISs) for free radical polymerization of trimethylolpropane triacrylate (TMPTA) and cationic polymerization of triethyleneglycol divinyl ether (DVE-3). The photopolymerization of the thiol-ene system trimethylolpropane tris(3-mercaptopropionate) (Trithiol)/DVE-3 with 5HNQ or 2HNQ based PISs are also investigated. 5HNQ shows maximum absorption in visible light region (blue light) which thus has the potential to perform under the irradiation of blue LED light. For the free radical polymerization of TMPTA, 5HNQ/Iod/NPG shows the highest photoinitiating ability among all the naphthoquinone derivative-based PISs, while 2HNQ-based systems are inefficient. The addition of Trithiol to TMPTA can significantly increase the double bond conversion of TMPTA during the photopolymerization. For the cationic photopolymerization of DVE-3, 2HNQ/Iod shows the highest photoinitiating ability among all the naphthoquinone derivative-based photoinitiating systems. 5HNQ-based systems also demonstrate good photoinitiation ability for DVE-3, but with slower polymerization rate compared to 2HNQ-based systems. In thiol-ene photopolymerization, 5HNQ PISs shows better photoinitiation ability than 2HNQ PIs systems. The results illustrate that the position of hydroxyl group in 1,4-naphthoquinone molecules plays an important role on photoinitiation ability of naphthoquinone derivatives. Steady state photolysis and electron spin resonance trapping experiments are also carried out to evaluate the relevant photochemical mechanism.

Halogenated and non-halogenated N-(4-phenyl-3-aroyl-2(3H)-ylidene) substituted acetamides were prepared by base-catalyzed cyclization of corresponding acetyl thioureas with phenacyl bromide. The synthesized compounds were structurally characterized by 1H NMR and 13C NMR spectroscopy and were screened against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzyme inhibition activities. Molecular docking studies, drug-like profiling and kinetic analysis were performed to further investigate the inhibition mechanism of the compounds. This study provided useful insights into the design and development of novel dual inhibitors, in addition to understanding the mechanism by which such drugs interact with targets and exert their biochemical action. All the compounds showed superior inhibition profile compared to the standards possessing sub-micromolar and micromolar IC50 values for AChE and BChE, respectively. Docking simulations revealed that the compound 6g showed strong binding inside the active site gorges of both AChE and BChE. An excellent agreement was obtained as the best docked poses showed important binding features mostly based on interactions due to aromatic moieties and oxygen atoms of the compound. Cation-pi/pi-pi interactions together with hydrogen bond forces were the key players responsible for ligand anchoring in the active sites. The striking results accomplished both in docking computations and experimental findings ascertained that the compound 6g can serve as a scaffold for both AChE and BChE inhibition.

A series of new hydrazonothiazolines (3a-v) was obtained in good to excellent yields (79–96%) via cyclization of the appropriate thiosemicarbazones with phenacyl bromide. The targeted compounds were characterized by advanced spectroscopic techniques, such as FTIR, 1HNMR, 13CNMR and ESI-MS. The structure of compounds 3n and 3v was unambiguously confirmed by single crystal X-ray analysis. All compounds displayed enhanced inhibitory activity against urease enzyme with IC50 values in range of 1.73 ± 1.57–27.3 ± 0.655 μM when compared to standard thiourea (IC50 = 20.8 ± 0.75 µM). The structure-activity relationship studies demonstrated that the activity of this series is due the central thiazole ring that interacts with nickel atoms in the active site of urease enzyme. Moreover, molecular docking studies were carried out to investigate the binding mode of all active compounds and an inactive (3u) with the active site of the urease enzyme. The docking results are in complete agreement with the experimental finding.

A series of chiral morpholino [4, 3-a] benzimidazole derivatives were synthesized effectively from (S)-(-)-2-(α-hydroxyethyl)-benzimidazole and phenacyl bromide derivatives using an efficient synthetic protocol in good yields and moderate diastereoselectivities. The substrate controlled diastereoselective route makes available structurally attractive morpholine-fused benzimidazole derivatives with two chiral centers in enantiomerically enriched forms. The preliminary biological evaluation shows scope for potential applications.

The behavior of thioacetoacetanilide (1) and/or α-arylhydrazono-thioacetoacetanilides 4 toward many different α-halocarbonyl compounds was demonstrated. Thus, reactions of 1 with α-bromoketones (bromoacetone and phenacyl bromide) and hydrazonoyl bromides afforded the corresponding thiazole, thiophene and 1,3,4-thiadiazole derivatives, respectively. The synthesis and reactivity of thiazolidin-5-one 2 toward aromatic diazonium chlorides and aromatic aldehydes were described. Most of the synthesized compounds were screened for their antibacterial and antifungal activities and showed accepted antimicrobial activities with respect to the control drugs.

Purpose – The study aims to synthesise new thiophene-based dyes by an efficient method using sodium a-cyanoketene dithiolates as starting components for synthesis of tetra-substituted thiophenes, which act as a coupler for the synthesised dye. The synthesised dyes are applied for printing polyamide and polyester fabrics using the screen printing technique. Design/methodology/approach – Treatment of 1 with carbon disulfide in alkaline medium forming disodium salt 2, which act as starting point for heterocyclisation to prepare these dye stuff 7. Sodium a-cyanoketene dithiolates 2 react with two moles of phenacyl bromide derivatives, forming alkylsulfanylthiophenes which react with the diazonium salt, forming the target dyestuff. These prepared dyes are used to print polyamide and polyester fabrics by using a synthetic thickener in the printing paste using screen-printing techniques. Findings – The structure of synthesised dyes were established and confirmed for the reaction products on the basis of their elemental analysis and spectral data (IR and 1H-NMR). The suitability of the prepared dyestuffs for screen printing on polyamide and polyester fabrics has been investigated. The prints obtained from dyes possess high colour strength as well as excellent overall fastness properties. Research limitations/implications – The diazo coupling reaction of the starting tetra-substituted thiophene 5 with diazotised aromatic amines resulted in the formation of the corresponding dye. The synthesised dyes were utilised in preparing a paste for polyester and polyamide fabric printing. In addition, both of the variations of the substituents on the synthesised dyes and the fastness properties were also studied. Practical implications – The synthesised dyes are superior in terms of yield, purity, colour strength and fastness properties, which lead to valuable achievements for commercial production. Social implications – The synthesised dyes are superior for application in fabrics. Originality/value – The synthesis for novel thiophene-based dye stuff for application in printing properties on polyester and polyamide fabrics and study their fastness properties.

N-{(E)-(dimethylamino)methylidenearbamothioyl}-4-toluenesulfonamide (2) was obtained by reaction of N-carbamothioyl-4-toluenesulfonamide (1) with dimethylformamide dimethylacetal or alternatively by the reaction of 1-(dimethylamino)methylidenethiourea with tosyl chloride. Compound 2 was reacted with substituted anilines to yield anilinomethylidine derivatives 3a, 3b, 3c, 3d, 3e, 3f, 3g. Treatment of 3a, 3b, 3c, 3d, 3e, 3f, 3g with phenacyl bromide gave triazepines 4a, 4b, 4c, 4d, 4e, 4f, 4g and imidazoles 5a, 5b, 5c, 5d, 5e, 5f, 5g. Esterification of compound 3e afforded ester derivative 6, which was subjected to react with hydrazine to yield hydrazide derivative 7. Oxadiazole 8 was obtained by reaction of 7 with CS2/KOH. Compound 3e was treated with o-aminophenol or o-aminothiophenol to give benzazoles 9a, 9b. N-(Diaminomethylidene)-4-toluenesulfonamide (10) reacted with enaminones to yield pyrimidines 11, 12, 13, respectively. The structures of the compounds were elucidated by elemental and spectral analyses. Some selected compounds were screened for their in vitro antifungal activity. In general, the newly synthesized compounds showed good antifungal activity.

A highly efficient domino Michael/cyclization reaction was developed for the synthesis of cyclopentanols and cyclopentenes with four and three stereogenic centers that were generated in one-pot reaction conditions with high diastereoselectivity. The reactions proceeded through a one-pot three-component reaction of β-nitrostyrenes, malononitrile and phenacyl bromide derivatives in basic media at room temperature.

1,3-Thiazol derivatives have been synthesized via reaction of 1-(1-(5,6-dimethoxy-2-oxobenzo[d]thiazol-3(2H)-yl)propan-2-ylidene)-4-substituted thiosemicarbazide with different halides, namely, ethyl bromoacetate, ethyl-2-bromopropionate, phenacyl bromide, p-bromophenacyl bromide and/or substituted hydrazonoyl halides. The new compounds were evaluated as antimicrobial agents.

A novel series of imidazo[1,2-a]pyridinopyrimidine-2,4,6(1H,3H,5H)-triones and thioxopyrimidine-4,6(1H,5H)diones were synthesized via multistep synthesis starting from 2-aminopyridine on cyclisation with phenacyl bromide followed by Vilsmeier–Haack and Knoevenagel condensation reactions. Structures of all the newly synthesized compounds were confirmed by their spectral and analytical studies. All the synthesized compounds were screened for their in vitro antimicrobial activity. Antibacterial activity results revealed that compounds 5f, 5i, and 5j have shown promising activity against S. pyogenes with ZOI ranging from 19 to 20 mm, compound 5g against P. aeruginosa (ZOI 19 mm) and 5f and 5h against S. aureus (ZOI 17, 18 mm) have shown good antibacterial activity. Among barbituric acid and thiobarbituric acid derivatives, thiobarbituric acid derivatives have shown maximum antibacterial activity. None of the compounds were found to be active at 150 µg/mL concentration against tested fungal strains.

The starting 3-(3,5-dimethyl-1H-pyrazol-1-yl)-3-oxopropanenitrile (1) reacts with phenyl isothiocyanate and ethyl bromoacetate to give the corresponding thiazole derivative 4. On repetition of the reaction using phenacyl bromides 5a–d (instead of ethyl bromoacetate), oxathiepine-6-carbonitriles 10a–d were obtained. Coupling of compound 1 with aryldiazonium chlorides gives the corresponding 2-(arylhydrazono)-(3,5-dimethyl-1H-pyrazol-1-yl)-3-oxopropanenitrile derivatives 12a–e, which on treatment with p-phenylenediamine, followed by reaction of hydrazine hydrate afforded pyrazole derivatives 15a–d. The reaction of 1 with 5-amino-3-(cyanomethyl)-1H-pyrazole-4-carbonitrile afforded the respective 2-cyanomethyl-pyrazolo[1,5-a]pyrimidine-3-carbonitrile derivative 18. Compound 18 reacted with phenyl isothiocyanate in the presence of potassium hydroxide at room temperature and then phenacyl bromide was added; the pyrazolopyrimidines 24 were obtained. The structures of all the newly synthesized products were confirmed based on elemental, spectral data and a plausible mechanism has been postulated to account for their formation. Also, we evaluate the anticancer activity of some representative examples of the newly synthesized compounds.

A convenient, one-pot, three-component regioselective synthesis of novel 2,2′-(1,4-phenylene)-bis-(3-aryl-2-substituted imino-4-aryl-3H-thiazole) derivatives from 1,4-phenylene diisothiocyanate, aryl amines, and various phenacyl bromide, and also the regioselective synthesis of 3-alkyl-2-(aryl imino)-4-cyclopropyl-5-(2′-fluorophenyl)-thiazole derivatives from alkylisothiocyanate, aryl amines, and 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone in the presence of poly-4-vinyl pyridine as heterogenous basic catalyst are described. This efficient method produced the products at room temperature with excellent yields (82–96%). The structures of all products were characterized by spectral and elemental analyses. The antimicrobial activity of the synthesized compounds was evaluated against Salmonella enterica, Micrococcus luteus, Bacillus subtilis, and Pseudomonas aeruginosa.

A simple, efficient and eco-friendly method has been developed for quinoxaline synthesis from inexpensive and readily available diamines and phenacyl bromides by catalyst- and additive-free protocol.

Three regioisomeric thieno[c]azocine derivatives were prepared in six steps from bromothiophene carboxylic acids. The reaction sequence started with an esterification with isopropyl alcohol. The resulting esters were submitted to a Heck reaction with tert-butyl acrylate followed by catalytic hydrogenation. Subsequent Dieckmann condensation gave cyclopentathiophenes with a cyclic β-oxo ester motif, which were α-alkylated with phenacyl bromide to furnish 1,4-diketones. The latter were converted in the key step, a bismuth-catalyzed ring transformation with methylamine, yielding the racemic eight-membered ring lactams, that is, tetrahydrothieno[2,3-c]-, [3,2-c]-, and -[3,4-c]azocine derivatives in overall yields of 25%, 16% and 12%, respectively.

A novel approach for the synthesis of polysubstituted pyrroles has been followed through multicomponent reaction of nitro compounds, phenacyl bromide or its derivatives and dialkyl acetylene dicarboxylates using indium in dilute aqueous HCl at room temperature. The products are formed in high yields (75–87%) in 10–16 h.