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New series of thiazole derivatives were synthesized using 5-(aryldiazo)salicylaldehyde thiosemicarbazones 2a–i. Cyclocondensation of thiosemicarbazones 2a–i with chloroacetone afforded the correspo...

This study deals with the design of original benzofuran–chalcone hybrids as anticancer agents. First, the reaction of 6-methoxysaliciylaldehyde with chloroacetone and potassium carbonate was used to prepare 1-(6-methoxy-1-benzofuran-2-yl) ethanone (1) as a starting reagent. A novel series of chalcone derivatives 3a–h, obtained through Claisen–Schmidt condensation with aromatic aldehydes 2a–h containing 6-methoxy benzofuran moiety, was designed, synthesized, and evaluated in terms of anticancer activities. The synthesized compounds 3a–h were tested against two MDA-MB-231 (human breast cancer cell line) and A549 (human lung cancer cell line) in order to detect anticancer activity by MTT Assay. The results revealed that 2-acetylbenzofuran-chalcone hybrids have an anticancer effect, especially with the phenolate salt of chalcone derivative 3e which shows cytotoxic effects on lung cancer cells. These observations showed that novel hybrid chalcone derivatives with a phenolate and methoxy linked 2-acetylbenzofuran prodrug strategy would be an important and easy method to increase water solubility and anticancer activity.

New 4-acetyl-5-anilino-N-arylthiophene-2-carboxamide derivatives have been synthesized by reaction of 2-acetyl-3-oxo-N-phenylbutanethioamide with three different chloroacetamide reagents. The synthesized thiophenes have been used as precursors in preparation of various thiazole-thiophene hybrids via their condensation with thiosemicarbazide and following treatment of the corresponding thiosemicarbazone with chloroacetone and/or chloroacetic acid. The reaction of 4-acetyl-5-anilinothiophenes with DMF–DMA or malononitrile is the synthetic route to the targeted thieno[2,3-b]pyridine derivatives. Molecular structures of the synthesized compounds have been determined on the basis of IR, 1H and 13C NMR, and mass spectra. The synthesized thiophene-based compounds have been tested for in vitro cytotoxicity by the MTT assay using 5-flourouracil as a reference drug. Thiophene-2-carboxamide derivatives exhibit good inhibitory activity against four cell lines, especially those products that contain thiazolidinone ring or thiosemicarbazide moiety in their structures.

3-(2-Thienyl)-5-aryl-1-thiocarbamoyl-2-pyrazolines were reacted with chloroacetone derivatives and hydrazonyl chloride derivatives in ethanol to afford the corresponding thiazolylpyrazoline derivatives and thiophenylpyrazolyl-5-substituted aryl-diazenylthiazole derivatives, respectively. The structures of the newly synthesized compounds were elucidated by different elemental and spectral analyses (IR, mass, 1H and 13C NMR). The antimicrobial and antifungal activities of the newly synthesized compounds were evaluated against four bacterial species and five fungal strains. In addition, the antitumor activities of two of the newly synthesized compounds 1-(2-(5-(4-chlorophenyl)-3-(thiophen-2-yl)-4,5-dihydropyrazol-1-yl)-4-methyl thiazol-5-yl)ethan-1-one and 2-(5-(4-chlorophenyl)-3-(thiophen-2-yl)-4,5-dihydro-1H-pyrazol-1-yl)-4-methyl-5-(phenyl-diazenyl)thiazole against HEPG-2, HCT-116, MCF-7, BHK, and CACO-2 were evaluated. From the obtained results, we found that these two compounds were the most potent candidates towards all gram-positive and gram-negative bacteria, as well as the fungi studied. Also, the same two compounds showed strong antitumor activities against two of the tumor cell lines (HCT-116 and CACO-2).

6-[2-(Furan-2-yl)ethyl]-3-sulfanylidene-3,4-dihydro-1,2,4-triazin-5(2H)-one (1) reacted with chloroacetone to give S-acetonyl derivative which cyclized in ethanol under reflux to afford 6-[2-(furan-2-yl)-ethyl]-3-methyl-7H-[1,3]thiazolo[3,2-b][1,2,4]triazin-7-one. 2,4-Bis(furan-2-carbonyl)-6-[2-(furan-2-yl)-ethyl]-3-sulfanylidene-3,4-dihydro-1,2,4-triazin-5(2H)-one and 3-amino-6-[2-(furan-2-yl)ethyl]-2-{[6-(2-(furan-2-yl)ethyl)-5-oxo-2,5-dihydro-1,2,4-triazin-3-yl]sulfanyl}-3-methyl-7H-[1,3]thiazolo[3,2-b][1,2,4]-triazin-7-one were prepared by reaction of 1 with furoyl chloride and dibromoacetonitrile, respectively. Compound 1 also reacted with formaldehyde and with formaldehyde and benzylamine to give 2-hydroxymethyl and 2-(benzylaminomethyl) derivatives. The alkylation of 1 with methyl iodide, followed by treatment with hydrazine hydrate, afforded 6-[2-(furan-2-yl)ethyl]-2-hydrazinyl-1,2,4-triazin-5(2H)-one. Reactions of the latter with aromatic aldehydes and formic acid furnished 3-aryl- and 3-unsubstituted 6-[2-(furan-2-yl)ethyl][1,2,4]tri-azolo[4,3-b][1,2,4]triazin-7(1H)-ones, respectively, and triacetyl and tetrabromophthalazinyl derivatives were obtained by reacting hydrazinyltriazinone with acetic anhydride and tetrabromophthalic anhydride. The newly synthesized compounds were evaluated for their antimicrobial activity against some bacterial and fungal strains.

A novel series of 1-amino-2-substituted-5-piperidinyl-6,7,8,9-tertahydrothieno[2,3-c]isoquinolines (4a–e) was synthesized upon treatment of 4-cyano-1-piperidinyl-5,6,7,8-tetrahydroisoquinline-3(2H)-thione (2) with α-halo carbonyl compounds such as chloroacetone, ethyl chloroacetate, 2-bromoacetophenone, chloroacetamide, and chloroacetanilide. Construction the pyrrolyl ring associated with the thienotetrahydroisoquinoline moiety was achieved by treatment of compounds 4a, b with 2,5-dimethoxytertahydrofuran in acetic acid. 1-Pyrrolyl-2-substituted-thieno[2,3-c]isoquinolines 5a and 5b which in turn were used as multipurpose precursors for synthesis of other new heterocycles. Assignments of the chemical structures of the respectively synthesized thienotetrahydroisoquinolines and their derivatives were established on the bases of elemental and spectral techniques (Fourier transform infrared, 1H NMR, 13C NMR, and mass spectroscopy). Furthermore, certain compounds were screened for their antimicrobial activity which revealed promising activities against various pathogenic strains of bacteria and fungi.

The synthesis of cyclopropyl methyl ketones and highly strained fused substituted dihydrobenzopyran cyclopropyl lactones derived from coumarin carboxylates and chloroacetone in the presence of potassium carbonate is reported. One step synthetic access to the previously unknown dihydrobenzopyran cyclopropyl tricyclic ketals is achieved with wide substrate scope. Substituted coumarin carboxylates, phenylamides or a quinolin-2(1H)-one possessing alkyl electron donating (methyl, t-butyl) and electron withdrawing groups (F, Cl, Br, NO2) in the 4 or 6 positions formed the highly strained dihydrobenzopyran cyclopropyl tricyclic ketals in moderate yield alongside the expected coumarin carboxylate. Saturation or substitution at the 5-position or 6-OMe afforded no tricyclic ketal compound but solely coumarin carboxylates. The formation of both structures in selected derivatives was confirmed by X-ray crystallography. A plausible mechanism is proposed for the formation of the fused lactone; via intramolecular rearrangement of cis cyclopropyl methyl ketones with phenolic acetate via the formation of a hemiacetal.

The dissociative photoionization dynamics of the chloroacetone molecule (C3H5OCl) in the gas phase, induced by vacuum ultraviolet (VUV) synchrotron radiation in the range from 10.85 to 21.50 eV, has been investigated by using time-of-flight mass spectrometry in the photoelectron-photoion coincidence mode. The appearance energies for the most relevant cation fragments produced in this energy range have been analyzed, and the fragmentation pathways leading to the formation of the cation species have been proposed and discussed. The mass spectra show that the most dominant VUV photodissociation cation product appears at m/z 43 and has been assigned to the C2H3O+ species. Enthalpies of formation (ΔfH°0K) for the neutral chloroacetone molecule and its molecular cation have been derived and correspond to -207.8 ± 5.8 kJ/mol and 755.1 ± 6.8 kJ/mol, respectively. In addition to the spectral analysis, the structural and energetic parameters for the cations produced have also been examined on the basis of high-level quantum chemical numerical calculations.

Ammonium perchlorate (AP) is most often used as a practical solid rocket propellant because of its excellent performance. However, AP has many shortcomings, including instability, high negative enthalpy of formation, and claimed health and environmental issues resulting from its combustion products. The pursuit of highly dense, high-performance, and environmentally friendly oxidizers as solid propellants has long attracted scientists around the world. In this work, bis(3-nitro-1-(trinitromethyl)-1H-1,2,4-triazol-5-yl)methanone (3) was obtained from bis(3-nitro-1H-1,2,4-triazol-5-yl)methane (1) with chloroacetone followed by nitration. The structure of 3 was confirmed by elemental analysis and single-crystal X-ray diffraction. By introducing the carbonyl moiety, the density of 3 was increased to 1.945 g/cm3 and the decomposition temperature increased to 164 °C. Compound 3 is a green energetic oxidizer that has a positive oxygen balance (+8.7%), a high specific impulse (218 s), and an acceptable sensitivity (9 J, 240 N), making it a practical replacement for AP in solid rocket propellant formulations.

From acetone and the orthoamide of phenylpropiolic acid (21b) N,N-dimethyl-phenylpropiolic acid amide (24) is formed. In contrast, the reaction of chloroacetone (28) with 21b results in the vinylogous guanidinium chloride 29. Unexpectedly, the Birckenbach-analogoue ethyl methyl ketone (34) reacts with the orthoamide 21b to give the push-pull-substituted butadiene 36. In contrast to this observation, the reaction of the Birckenbach-analogous acetophenones 30 with the orthoamides 21a – c delivers the push-pull-substituted 1,3,5-hexatrienes 31a – j.

A new series of coupled benzofuran derivatives that contain the trifluoromethyl group and pyrazole moiety is synthesized for evaluation of their anti-inflammatory and analgesic activities. Their synthesis proceeds via cyclocondensation of 2-hydroxy-4-(trifluoromethyl)benzaldehyde with chloroacetone with formation of 2-acetylbenzofuran, which upon treatment with different aldehydes via the Claisen-Schmidt condensation gives the corresponding chalcones. Cyclization of chalcones with hydrazine hydrate leads to pyrazoline derivatives, that exhibit significant anti-inflammatory and analgesic activities. Docking modelling of selected active compounds are correlated well with their anti-inflammatory tests data.

Alkyl(hetero)aromatic α-hydroxyamino oximes with the anti configuration of the oxime group reacted with ethyl glyoxylate to form 5-aryl(hetaryl)-1-hydroxy-1H-imidazole-2-carboxylic acid ethyl esters. In the case of 4-fluorophenyl-, 4-chlorophenyl-, and 4-methoxyphenyl-substituted α-hydroxyamino oximes, 3-aryl-5-hydroxy-5,6-dihydro-4H-1,2,5-oxadiazine-6-carboxylic acid ethyl esters were also formed. The positions of the substituents in the imidazole ring were established on the basis of a comparative analysis of the spectroscopic data of these products and the synthesized isomeric compound, 1-hydroxy-5-methyl-4-phenyl-1H-imidazole-2-carboxylic acid ethyl ester. 5-Aryl(hetaryl)-1H-imidazole-2-carboxylic acids were obtained in the reaction of 5-aryl(hetaryl)-1-hydroxy-1H-imidazole-2-carboxylic acids ethyl esters with chloroacetone.

p-Sulphonic-N-propionyl aniline 3 was produced from sulphanilic acid with propionic acid under reflux for 2 h, then the compound 3 reacted with thionyl chloride and the corresponding imidoyl chloride 4 was obtained. When imidoyl chloride 4 reacted with potassium isothiocyanate and aniline, the corresponding thiourea derivatives 6 was produced. Compound 6 was reacted with tricyanovinylamine to produce the thiazole derivative 7 after cyclization. The microwave-assisted condensation of 2,3,4.6,-tetra-O-acetyl-β-D-glucopyranosylisothiocynate 8 with thiazole derivative 7 afforded the thiourea derivatives 9. Compound 10 a, b has been synthesized by reacting thiourea derivatives 9 with chloroacetone. The prepared compounds were screened for antibacterial properties against Staphylococcus aureus and Escherichia coli, and antifungal activity against Candida sp. The structure assignments of the new synthesized compounds are based on spectroscopic data.

A novel series of substituted 4,6-dimethyl-2-oxo-1-(thiazol-2-ylamino)-1,2-dihydropyridine-3-carbonitrile derivatives 6, 9, 13, 15, and 17 was synthesized in a good to excellent yield from the reaction of 1-(3-cyano-4,6-dimethyl-2-oxopyridin-1(2H)-yl)thiourea with 2-oxo-N'-arylpropanehydrazonoyl chloride, chloroacetone, α-bromoketones, ethyl chloroacetate, and 2,3-dichloroquinoxaline, respectively. The potential DNA gyrase inhibitory activity was examined using in silico molecular docking simulation. The novel thiazoles exhibit dock score values between − 6.4 and − 9.2 kcal/mol and they were screened for their antimicrobial activities. Compound 13a shown good antibacterial activities with MIC ranged from 93.7–46.9 μg/mL, in addition, it shown good antifungal activities with MIC ranged from 7.8 and 5.8 μg/mL.

Orientador: Prof. Dr. Alexsandre Figueiredo Lago Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência e Tecnologia/Química, Santo André, 2021. Os compostos organoclorados, dentre os quais destacam-se as moléculas de 1,2-dicloropropano e cloroacetona, possuem uma grande versatilidade de aplicações em processos químicos e farmacêuticos. Contudo, o comportamento desses compostos no meio ambiente é de grande preocupação para a comunidade científica, uma vez que essas moléculas podem participar da formação de subprodutos secundários que podem ser originados por meio de processos de fotoionização e fotofragmentação e que podem apresentar um papel importante na dinâmica das reações químicas que se desenvolvem na atmosfera. Apesar da relevância do tema em questão, poucos estudos contemplando o comportamento dessas espécies frente à exposição à radiação eletromagnética, bem como suas estruturas eletrônicas, encontram-se disponíveis na literatura. O projeto desenvolvido apresenta um caráter fortemente interdisciplinar, englobando subáreas experimentais e teóricas importantes da química, permitindo uma melhor compreensão de propriedades fundamentais das espécies em estudo e uma discussão mais bem justificada dos resultados obtidos. Além disso, o acesso e o domínio das diversas áreas científicas envolvidas nesse trabalho servirão como base importante para novos projetos a serem desenvolvidos na área de espectroscopia e termoquímica de sistemas moleculares de interesse científico em fase gasosa. O presente trabalho consiste, portanto, na investigação da dinâmica de ionização dissociativa e propriedades correlatas desses sistemas moleculares em fase gasosa na faixa de radiação do ultravioleta de vácuo por meio da espectrometria de massas por tempo de voo acoplada com a técnica de espectroscopia de coincidência fotoelétron-fotoíon, empregando a radiação Síncrotron, onde as possíveis reações referentes aos canais de fragmentação observados foram propostas e discutidas, bem como no estudo teórico das propriedades estruturais, eletrônicas e termoquímicas das espécies observadas por meio de métodos computacionais avançados, que proporcionaram dados acurados sobre propriedades fundamentais sobre as espécies em estudo e que serviram como uma base importante para a discussão dos resultados experimentais obtidos. Os resultados teóricos demonstraram que a molécula isolada de cloroacetona possui dois isômeros conformacionais, sendo a estrutura contendo o átomo de cloro em uma configuração limiar entre as conformações gauche/cis com respeito ao grupo metila mais estável em relação à conformação trans, ao passo que para o cátion molecular, somente a conformacao gauche foi encontrada como uma estrutura estavel. A analise experimental dos espectros de massa demonstrou que o principal canal de fragmentacao na faixa de energia de 10,85 a 21,28 eV corresponde a formacao do cation com m/z=43. A partir de dados disponiveis na literatura, foi possivel derivar as entalpias de formacao (¿¢....0(..,0..)) da molecula neutra de cloroacetona e de seu cation molecular por meio de rotas termoquimicas, obtendo-se os valores de -207,8 } 5,8 kJ/mol e 755,1 } 6,8 kJ/mol. De acordo com os resultados teoricos para o 1,2-dicloropropano, a conformacao mais estavel para a molecula neutra isolada corresponde aos atomos de cloro em configuracao trans, sendo as outras conformacoes estaveis correspondentes aos atomos de cloro em uma conformacao (+) gauche e (-) gauche, enquanto para o cation molecular, alem dessas configuracoes, verifica-se a existencia dos isomeros em uma conformacao (+) quase cis e (-) quase cis, sendo o ultimo correspondente a conformacao de menor energia. A analise de seus espectros de massa, por sua vez, foi efetuada por meio da obtencao dos espectros de massa na faixa de energia de 11,26 a 21,56 eV e demonstrou que os principais canais de dissociacao resultam nas especies formadas com razao m/z=62, m/z=63 e m/z=76. Por fim, uma analise comparativa das estruturas, propriedades e dinamicas de dissociacao de ambas as especies foi realizada. Os resultados obtidos nesse trabalho podem fornecer meios para uma melhor compreensao da estabilidade e reatividade dessas especies, bem como servir de modelo para determinacao de propriedades fotoquimicas e fotofisicas de moleculas halogenadas e carbonilicas semelhantes. The organochlorine compounds, among which the 1,2-dichloropropane and the chloroacetone molecules can be highlighted, display a great versatility of applications in chemical and pharmaceutical processes. The behavior of these compounds in the environment is of significant concern for the scientific community, since they can take part in the formation of secondary subproducts, which can be originated through the photoionization and photofragmentation processes and may play an important role in the dynamics of chemical reactions that take place in the atmosphere. In spite of the relevance of the given topic, only few studies concerning the behavior of these species when exposed to the electromagnetic radiation or their electronic structures are available in the literature. The developed project presents a strong interdisciplinary character and encompasses important experimental and theoretical branches of chemistry, allowing a better comprehension of fundamental properties of the species under study and a more justified discussion of the obtained results. Besides, the access and mastering of the several scientific branches involved in this work will serve as an important basis for new projects yet to be developed in the fields of spectroscopy and thermochemistry of molecular systems of scientific interest in the gas phase. Therefore, the present work is based on the investigation of the dissociative ionization dynamics and related properties of these molecular systems in the gas phase in the energy range of the vacuum ultraviolet radiation by employing the time-of-flight mass spectrometry coupled with the photoelectron-photoion coincidence spectroscopy and the synchrotron radiation, where the possible reactions leading to the fragmentation channels observed were proposed and discussed, as well as the theoretical study of the structural, electronic and thermochemical properties of the species observed by means of advanced computational methods, which provided accurate data on fundamental properties of the species under investigation and served as an important basis for the discussion of the experimental results obtained The theoretical results have shown that the isolated chloroacetone neutral molecule displays two conformational isomers, being the structure with the chlorine atom on the edge of a gauche/cis conformation with respect to the methyl group more stable in comparison with the trans conformation, as for the molecular cation, only the gauche conformation was found as a stable structure. The analysis of the mass spectra has shown that the main photofragmentation channel in the energy range of 10.85 ¿ 21.28 eV corresponds to the formation of the cation species at m/z=43. From the data available in the literature, the enthalpies of formation (¿¢....0(..,0..)) of the neutral molecule and its molecular cation have been derived by means of thermochemical routes as -207.8 } 5.8 kJ/mol and 755.1 } 6.8 kJ/mol., respectively. According to the theoretical results for the 1,2-dichloropropane, the most stable conformation of the isolated neutral molecule corresponds to the trans conformation involving the chlorine atoms, as the other stable structures present these atoms with the (+) gauche and (-) gauche conformations, as the molecular cation, besides from these configurations, presents the (+) near cis and (-) near cis isomers, being the latter regarded as the most stable structure. From the respective mass spectra, which were collected in the energy range from 11.26 to 21.56 eV, it was shown that the main dissociation channels of the 1,2-dichloropropane molecule led to the formation of the cation species at m/z=62, m/z=63 and m/z=76. Finally, a comparative analysis on the structures, properties and dissociation dynamics of both species was performed. The results obtained in this work may provide means for a better comprehension of the stability and reactivity of these species and serve as a model for the determination of photochemical and photophysical properties of similar halogenated and carbonyl compounds.

Development of new derivatives of commercial antibiotics using different organic reagents and testing these derivatives against different microorganisms are the main goals of this article. Thus, the antibiotic ciprofloxacin, CF, was acylated via reaction with ethyl cyanoacetate and ethyl acetoacetate in basic medium to give the cyanoacetylpiprazinyl dihydroquinoline derivative 3, and oxobutanoylpiprazinyl dihydroquinoline derivative 5, respectively. On the other hand, N-alkylated derivatives 8–10, were prepared through the reaction of CF with chloroacetonitrile, chloroacetyl acetone and chloroacetone in the presence of carbonate salt. In basic medium, both 3 and 10 were coupled with benzenediazonium chloride to afford hydrazono derivatives, which were then cyclized to give 4-(dihydropyridazinecarbonyl)piperazinyl-1,4-dihydroquinoline. Furthermore, compounds 3 and 10 were reacted with benylidenemalononitrile to produce 4H-pyan and pyrido[1,2-a]pyrazine derivatives, respectively. Both 3 and 10 were reacted with DMFDMA to give enaminone derivatives. These enaminones were cyclized to aminopyrimidine derivatives by reacting with urea or thiourea. X-ray, elemental analysis and spectral data were used to illustrate and confirm the structures of the isolated compounds. The bioactivities of the novel compounds were investigated against different gram-positive and gram-negative bacteria. In addition, these novel antibiotic derivatives were tested against ciprofloxacin-resistant bacteria isolated from patients aged 65–74 years. This study reveals that most of the modified drugs show high to moderate antibacterial activity. Additionally, these drugs show good effects against ciprofloxacin-resistant bacteria.

A facile synthesis of 3‑hydroxy-4-(4-hydroxyphenylazo)thiophenes with various functional groups at position-2 of thiophene ring and their corresponding O-acetylated products is described. The synthetic strategy is based on cyclization of the precursor ethyl 2-(2-(4-hydroxyphenyl)hydrazono)-3-(phenylamino)-3-thioxopropanoate with the appropriate α-chlorinated reagents (namely; chloroacetone, phenacyl chloride, ethyl chloroacetate and chloroacetonitrile). The produced 3‑hydroxy-4-(4-hydroxyphenylazo)thiophenes were acetylated upon heating in acetic anhydride to yield the corresponding 3‑hydroxy-4-(4-acetoxyphenylazo)thiophenes and/or 3-acetoxy-4-(4-acetoxyphenylazo)thiophenes. The synthesized thiophene derivatives were characterized by IR, 1H NMR and mass spectroscopic analyses. The DFT modeling of the synthesized derivatives offered a reasonable description about why the acetylation reaction was occurred on the phenolic O H group rather than the O H group at position-3 of thiophene ring. While in case of 2-cyano-3‑hydroxy-4-(4-hydroxyphenylazo)-5-(phenylamino)-thiophene, both hydroxyl groups were acetylated. The antioxidant activities for the synthesized compounds were assessed through DPPH technique. The 3-hydroxythiophene derivatives 5a-c displayed significant activity with IC50 values (3.01–26.27 µg/mL) using BHA, BHT and ascorbic acid as reference antioxidants. Meanwhile, the results of molecular docking study that applied on the synthesized thiophene derivatives supported the experimental antioxidant assay.

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 ...

An experimental study on the 3-chloro-2-methyl-1-propene (CMP), 2,3-dichloropropene (DCP) and 3,4-dichlorobutene (DCB) reactions with atmospheric oxidants at (298 ± 1) K and atmospheric pressure is reported. Rate constants for the gas phase reactions of the three chlorinated alkenes with O3, OH and NO3 radicals and Cl atom were determined in a 100 L Teflon reactor by gas chromatography with flame ionization detector (GC-FID). The obtained rate constants are (3.03 ± 0.15) × 10−18, (3.83 ± 1.30) × 10−11, (1.99 ± 0.19) × 10−14, and (2.40 ± 0.41) × 10−10 cm3 molecule−1 s−1 for CMP reactions with O3, OH, NO3, and Cl, respectively, (4.62 ± 1.41) × 10−20, (1.37 ± 1.02) × 10−11, (1.45 ± 0.15) × 10−15 and (1.30 ± 0.99) × 10−11 cm3 molecule−1 s−1 for DCP reactions and (2.09 ± 0.24) × 10−19, (1.45 ± 0.59) × 10−11, (3.00 ± 0.82) × 10−16 and (1.91 ± 0.19) × 10−10 cm3 molecule−1 s−1 for DCB reactions. The CMP reaction products were detected and possible reaction mechanisms of their formation were proposed. Chloroacetone was found to be the major product in all four oxidation reactions. The loss process of CMP in the atmosphere is mostly controlled by its reaction with the OH radical during daytime and with NO3 during nighttime, with lifetimes of 3.6 h and 27.9 h respectively. Atmospheric implications of both these reactions and their potential products are discussed.

Aim. Optimization of reaction of substituted 5-aminopyrazoles with a-haloketones to form annealed 2,6,7-trisubstituted 1H-imidazo[1,2-b]pyrazoles. Materials and methods of research. The methods of organic synthesis, instrumental methods of organic compound analysis were used. Results. A scheme for the synthesis of 2,6,7-trisubstituted 1H-imidazo[1,2-b]pyrazoles by the interaction of 5-amino-4-arylsulfonyl-3-methylthiopyrazoles 1a-b with chloroacetone, phenacyl bromide and 2-chlorocyclohexanone was developed. In contrast to the previously described interaction of substituted 5-aminopyrazoles with chloro (N-aryl) acetamides proceeding exclusively with the release of N 1 -alkylation products, in this reaction a mixture of N 1 - and N 2 -isomeric alkylation products is formed. The ratio of isomers depends on the nature of the reagents and, according to the 1H NMR-spectroscopy, is about 60:40 %.The developed technique allows with one of the synthetic procedure to carry out N 1 -alkylation of 5-aminopyrazoles 1a-b and the cyclization of products 2 in imidazo[1,2-b]pyrazoles 4a-c without isolating the N 2 -alkylation product. The purity of the obtained compounds is proved chromatographically, the structure is confirmed by the data of 1H NMR-spectroscopy. Conclusions. Optimized reaction of substituted 5-aminopyrazoles with a-haloketones to form annealed 2,6,7-trisubstituted 1H-imidazo[1,2-b]pyrazoles for targeted synthesis of the novel agents for the pharmaceutical practice

A novel series of coumarins, thiadiazoles, thiazoles, and pyridines were synthesized via reaction of 5-bromosalicylaldehyde with different reagents. Thus, 5-bromosalicylaldehyde 1 was reacted with compounds 2a–d affording iminocoumarins 3a–d, which on hydrolysis with 10% hydrochloric acid, afforded coumarins 4a–d, respectively. On the other hand, reaction of 1 with benzylhydrazinecarbodithioate 5 afforded derivative 6, which reacted with hydrazonoyl halides 7a–f, afforded 1,3,4-thiadiazoles 11a–f, respectively. Moreover, thiazoles 15 and 16 were obtained via reaction of 1 with thiocarbohydrazide 13 and hydrazonoyl halides. However, condensation of 2-acetyl-5-bromobenzofuran 17 with benzaldehyde afforded chalcone 18, which reacted with pyridiniumbromides 19a–c, afforded pyridines 20a–c, respectively. Furthermore, pyridines 21–24 were synthesized from the reaction of chalcone 18 with different active methylene compounds. Reaction of 24 with ethylchloroacetate, chloroacetone, and chloroacetonitrile afforded thienopyridines 26a–c, respectively. The structures of the newly synthesized compounds were established based on their spectral data and elemental analyses. Also, selected newly synthesized compounds were screened for their antimicrobial activity against various microorganisms by disk diffusion method.

The reaction of 2,6-bis(hydroxyimino)cyclohexan-1-one with aldehydes and ammonia afforded 2-substituted 4-hydroxyimino-4,5,6,7-tetrahydro-1H-benzimidazol-1-ols which were hydrolyzed to 1-hydroxy- 2-R-1,5,6,7-tetrahydro-4H-benzimidazol-4-ones. The N-hydroxy group in the latter can readily by removed by the action of chloroacetone in the presence of a base (potassium carbonate or triethylamine); as a result, 2-substituted 1,5,6,7-tetrahydro-4H-benzimidazol-4-ones were obtained.

The concise and efficient total syntheses of the naturally-occurring coumarin derivatives gerberinol I, and the pterophyllins 2 and 4, from 5-methyl-4-hydroxycoumarin as a common precursor employing different Casnati-Skattebøl reaction conditions, are reported. The synthesis of the key intermediate coumarin was achieved by the organocatalytic condensation of acetylacetone and crotonaldehyde followed by a LiCl-assisted cyclization, CuCl2-promoted aromatization and a final Et2CO3-mediated cyclization. A Casnati-Skattebøl formylation under high-temperature conditions afforded gerberinol I, whereas milder conditions resulted in an unstable 3-formyl-4-hydroxycoumarin derivative, which was subjected to a basic alumina-mediated one pot O-alkylation with chloroacetone and intramolecular aldolization to furnish pterophyllin 4. Wittig methylenation of the latter conveniently afforded pterophyllin 2. Fil: Pergomet, Jorgelina Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Bracca, Andrea Beatriz Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Kaufman, Teodoro Saul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina

The detailed reaction mechanism of 3-chloro-2-methyl-1-propene (3CMP) with OH radical was investigated by employing highly accurate electronic structure calculations and kinetic modelling. Due to the unsaturated structure of 3CMP, it is highly reactive in the troposphere with OH radical. The fate of the so-formed alkyl radical intermediates and intermediate adducts in the favourable pathways is determined by its reaction with other atmospheric oxidants, such as HO2, NO and NO2 radicals. The rate constants computed within the temperature range of 200–1000 K for the favourable hydrogen atom abstraction and OH radical addition reactions are in reasonable agreement with the available experimental values. The oxidation of 3CMP results in the formation of stable chlorinated products, such as chloroacetone and formyl chloride, which are identified experimentally. These products may be transported to the stratosphere which will affect the ozone layer.

Western Australia is a semi-/arid region known for saline lakes with a wide range of geochemical parameters (pH 2.5&ndash, 7.1, Cl&minus, 10&ndash, 200 g L&minus, 1). This study reports on the haloacetones chloro- and bromoacetone in air over 6 salt lake shorelines. Significant emissions of chloroacetone (up to 0.2 &micro, mol m&minus, 2 h&minus, 1) and bromoacetone (up to 1. 5 &micro, 1) were detected, and a photochemical box model was employed to evaluate the contribution of their atmospheric formation from the olefinic hydrocarbons propene and methacrolein in the gas phase. The measured concentrations could not explain the photochemical halogenation reaction, indicating a strong hitherto unknown source of haloacetones. Aqueous-phase reactions of haloacetones, investigated in the laboratory using humic acid in concentrated salt solutions, were identified as alternative formation pathway by liquid-phase reactions, acid catalyzed enolization of ketones, and subsequent halogenation. In order to verify this mechanism, we made measurements of the Henry&rsquo, s law constants, rate constants for hydrolysis and nucleophilic exchange with chloride, UV-spectra and quantum yields for the photolysis of bromoacetone and 1,1-dibromoacetone in the aqueous phase. We suggest that heterogeneous processes induced by humic substances in the quasi-liquid layer of the salt crust, particle surfaces and the lake water are the predominating pathways for the formation of the observed haloacetones.

The condensation of (2E)-N-hydroxy-2-hydroxyimino-2-phenylethanamine with 3,4,5-trimethoxyphenylglyoxal afforded (1-hydroxy-5-phenyl-1H-imidazol-2-yl)phenylmethanone which reacted with trimethyl phosphite or chloroacetone to give 2-(3,4,5-trimethoxybenzoyl)-4(5)-phenyl-1H-imidazole.

N-(2-Hydroxyethyl)morpholine and chloroacetone form a new spirane compound, (R/S)-di-(N-morpholinyl-spiro-β‑hydroxy-β-methylmorpholinyl chloride) hydrate (1). The molecular structure and spectroscopic properties of this salt were characterized by the single-crystal X-ray diffraction, DFT calculations, FTIR and NMR spectroscopies. The crystals of compound 1 are monoclinic, P21/c space group. Compound 1 consists of two non-equivalent spiro units (R and S). Each unit is built of two morpholine rings joined at the N(1) spiro center. The spiro units are linked by a water molecule through the O(W)−H(WA)⋅⋅⋅Cl(1) hydrogen bond of 3.141(7) A with R-isomer and by an unusual interaction of water with the electron pair of morpholine oxygen atom of the other S-isomer. The total energy, geometry and natural atomic charges, calculated at the B3LYP/6–311++G(d,p) level of theory, for studied compound and for R and S isomers were analyzed. The C−H⋅⋅⋅Cl contacts were confirmed by calculations based on the quantum theory of atoms in molecule (QTAIM). The 1H and 13C chemical shifts were assigned by two-dimensional techniques, COSY, HSQC and HMBC. The experimental and computed infrared spectra were compared. The potential energy distribution (PED) was used to assign the vibrational spectra. Diagrams of HOMO and LUMO are presented and discussed.

A straightforward approach toward 6-bromo-2-isopropylidenecoumaranone, a potential intermediate toward alkaloid TMC 120-B, pseudodeflectusin, and other natural products, was reported. The synthetic sequence involved the reaction of 3-bromosalicylaldehyde with chloroacetone and cyclization of the resulting ether to a 2-acetylcoumaranol intermediate. This was followed by sequential methyl Grignard addition and Jones' oxidation to the corresponding coumaranone, which was dehydrated to the final product with the methanesulfonyl chloride/pyridine reagent. The protection of the coumaranol as the corresponding THP-ether resulted in improved product yields. Fil: Pergomet, Jorgelina Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Kaufman, Teodoro Saul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Bracca, Andrea Beatriz Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina

Portable photocatalytic air cleaners were investigated in 24 and 48 m(3) emission test chambers with regard to efficiency and by-product generation. For this purpose, formaldehyde, decane, 1,2-dichlorobenzene, toluene, α-pinene and heptanal were doped at sub-ppm concentration levels into the chambers individually and in mixtures. By way of specified test protocols, efficiencies could be distinguished but were strongly dependant on the choice of test compounds, especially on whether single or multi compound dosing was used, and on long-term effects. Initial clean air delivery rates (CADRs) up to 137 m(3)/h were measured. Typical by-products were found in significant concentrations. The main ones were formaldehyde up to 50 ppb (62 μg/m(3)) and acetone up to 80 ppb (190 μg/m(3)). Other aldehydes were also found, but at smaller levels. The detection of chloroacetone, a strong irritating compound, at concentrations up to 15 ppb (57 μg/m(3)) strengthens the importance of such investigations especially in cases were chloro-organic compounds are involved.

A theoretical study on the structural, electronic and spectroscopic properties for the isolated chloroacetone (C3H5OCl) and its molecular cation was performed with ab initio and density functional theory methods. Two conformers were found stable for the neutral molecule, where the structure with the chlorine atom on the edge of a gauche/cis conformation with respect to the methyl group is more stable by 1.0 kcal/mol in comparison with the trans conformation. As for the molecular cation, only the gauche conformation was found stable. Theoretical first adiabatic ionization potential and vibrational frequencies investigated are in very good agreement with the experimental results.

The gas-phase reaction of Cl atom with 2,2,2-trifluoroethylacrylate (k1), 1,1,1,3,3,3-hexafluoroisopropylacrylate (k2), 2,2,2-trifluoroethylmethacrylate (k3) and 1,1,1,3,3,3-hexafluoroisopropylmethacrylate (k4), have been investigated at 298 K and 1 atm using the relative method by gas chromatography coupled with flame ionization detection (GC-FID). The values obtained are (in cm3 molecule−1 s−1): k1(Cl+CH2=CHC(O)OCH2CF3) = (2.41 ± 0.57) × 10−10, k2(Cl+CH2=CHC(O)OCH(CF3)2) = (1.39 ± 0.34) × 10−10, k3(Cl+CH2=C(CH3)C(O)OCH2CF3) = (2.22 ± 0.45) × 10−10, and k4(Cl +CH2=C(CH3)C(O)OCH(CF3)2 = (2.44 ± 0.52) × 10−10. Products identification studies were performed by solid-phase microextraction (SPME) method, with on-fiber products derivatization using o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine hydrochloride, coupled with gas chromatography with mass spectrometry detection (GC-MS). Chloroacetone, trifluoroacetaldehyde and formaldehyde were observed as degradation products and a general mechanism is proposed. Additionally, reactivity trends and atmospheric implications are discussed. Significant ozone photochemical potentials (POCP) and acidification potentials lead to local and or regional impact of the esters under study although is expected to a have a minor impact on global warming and climate change. Fil: Rivela Fretes, Cynthia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina Fil: Blanco, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina Fil: Teruel, Mariano Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina

Background The synthesis of new thiazole derivatives is very important because of their diverse biological activities. Also , many drugs containing thiazole ring in their skeletons are available in the market such as Abafungin, Acotiamide, Alagebrium, Amiphenazole, Brecanavir, Carumonam, Cefepime, and Cefmatilen. Results Ethyl cyanoacetate reacted with phenylisothiocyanate, chloroacetone, in two different basic mediums to afford the thiazole derivative 6, which reacted with dimethylformamide- dimethyl acetal in the presence of DMF to afford the unexpected thiazole derivative 11. The structures of the thiazoles 6 and 11 were optimized using B3LYP/6-31G(d,p) method. The experimentally and theoretically geometric parameters agreed very well. Also, the natural charges at the different atomic sites were predicted. HOMO and LUMO demands were discussed. The anticancer activity of the prepared compounds was evaluated and showed moderate activity. Conclusions Synthesis of novel thiazole derivatives was done. The structure was established using X-ray and spectral analysis. Optimized molecular structures at the B3LYP/6-31G(d,p) level were investigated. Thiazole derivative 11 has more electropositive S-atom than thiazole 6. The HOMO–LUMO energy gap is lower in the former compared to the latter. The synthesized compounds showed moderate anticancer activity. Electronic supplementary material The online version of this article (10.1186/s13065-018-0420-7) contains supplementary material, which is available to authorized users.

New ligand precursors with different pendent alky chain length were obtained in a single step by reacting appropriate 1-alkyl-2-methyl-1H-imidazoles with chloroacetone in THF at 80 °C overnight. Zwitterionic palladium complexes were prepared by reacting PdCl2 with these new imidazole derivatives in DMF with the presence of pyridine and Cs2CO3 as base at room temperature for 5 h. These new compounds were characterized by 1H and 13C{1H} NMR spectroscopy, elemental analysis, and electrospray ionization mass spectrometry. They were effectively applied as recyclable catalysts for mediating Mizoroki–Heck reactions in ionic liquids. Transmission emission microscopy revealed that palladium nanoparticles were formed during the catalytic process.

This current piece of research presents an easy and direct way for the synthesis of binuclear ortho-palladated phosphorus ylide derivatives of acetone and chloroacetone in high yield and high purity by the reaction of the phosphonium salts [CH3COCH2PPh3]Cl (1) and [ClCH2COCH2R]Cl (R = PPh3 (2), R = P(PhMe)3 (3)) with palladium(II) acetate in methanol under mild conditions to afford the dimeric orthopalladated complexes, [Pd(CH3COCHPPh3)(μ-Cl)]2 (4), [Pd(ClCH2COCHPPh3)(μ-Cl)]2 (5) and [Pd(ClCH2COCHP(PhMe)3)(μ-Cl)]2 (6).

The rate constants and products for the reactions of atomic Cl and O3 molecule with 3-methyl-3-buten-2-one (MBO332) and 3-methyl-3-penten-2-one (MPO332) were determined in a 100 L Teflon chamber at 293 ± 1 K and atmospheric pressure. For MBO332 and MPO332, the rate constants measured with atomic Cl were (2.38 ± 0.26) × 10(-10) and (3.00 ± 0.34) × 10(-10) cm(3) molecule(-1) s(-1) using the relative rate method. Using the absolute rate method, the rate constants with O3 measured were (1.18 ± 0.21) × 10(-17) and (4.07 ± 0.45) × 10(-17) cm(3) molecule(-1) s(-1). The products of these reactions were investigated by the proton-transfer-reaction mass spectrum (PTR-MS). The results indicated that the major products observed in the atomic Cl reaction were formaldehyde together with chloroacetone for MBO332, and acetaldehyde and CH3C(O)C(O)Cl for MPO332. For O3 reactions, butanedione and formaldehyde were the main products of MBO332, while butanedione and acetaldehyde were the main products of MPO332. Possible reaction mechanisms were proposed and discussed and the atmospheric implications of these reactions were also discussed.