2033-24-1Relevant articles and documents
Chemistry of diazocarbonyl compounds: XXVII. Thermolysis and photolysis of diazirines, derivatives of 1,3-dioxane-4,6-dione
Shevchenko,Khimich,Platz,Nikolaev
, p. 1213 - 1219 (2006)
Photolysis of diazirines, 1,3-dioxane-4,6-dione derivatives, occurs in the presence of methanol or dimethyl sulfide as carbene traps without a formation of carbene intermediates. It was established for the first time that the thermolysis and photolysis of diazirines from the 1,3-dioxane-4,6-dione series led mainly to Wolff rearrangement with a subsequent formation of 5-oxo-1,3-dioxolane-4-carboxylic acids or their derivatives. The data obtained show that the α-oxodiazirines are the key intermediates in the photolysis and Wolff rearrangement of α-diazocarbonyl compounds. Nauka/Interperiodica 2006.
Search for dioxocarbenes in photochemical reactions of 5-diazo-4,6-dioxo-1, 3-dioxanes, associated diazirines, and S-ylides
Shevchenko,Khimich,Platz,Nikolaev
, p. 435 - 438 (2005)
On direct photolysis of 2,2-dialkyl-5-diazo-4,6-dioxo-1,3-dioxanes in the presence of pyridine, methanol or dimethyl sulfide as carbene traps, the yield of 'carbene' products does not exceed 27-28%. At the same time photochemical transformations of the re
Experimental and Theoretical Investigation of Reversible Interconversion, Thermal Reactions, and Wavelength-Dependent Photochemistry of Diazo Meldrum's Acid and Its Diazirine Isomer, 6,6-Dimethyl-5,7-dioxa-1,2-diaza-spiro[2,5]oct-1-ene-4,8-dione
Bogdanova, Aneta,Popik, Vladimir V.
, p. 14153 - 14162 (2003)
The photochemical or thermal decomposition of diazo Meldrum's acid (1) in methanolic solutions yields ketoester 3a, the product of the Wolff rearrangement, while products produced from the singlet carbene were not detected. This observation, combined with the analysis of activation parameters for the thermal decomposition of 1, as well as with the results of DFT B3PW91/6-311+G(3df,2p) and MP2/aug-cc-pVTZ//B3PW91/6-311+G(3df,2p) calculations, allows us to conclude that the Wolff rearrangement of 1 is a concerted process. The outcome of the photolysis of diazo Meldrum's acid depends on the wavelength of irradiation. Irradiation with 254 nm light results in an efficient (Φ254 = 0.34) photo-Wolff reaction, while at 355 nm, the formation of diazirine 2 becomes the predominant process (Φ 350 = 0.024). This unusual wavelength selectivity indicates that Wolff rearrangement and isomerization originate from different electronically excited states of 1. The UV irradiation of diazirine 2 leads to the loss of nitrogen and the Wolff rearrangement, apparently via a carbene intermediate. This process is accompanied by a reverse isomerization to diazo Meldrum's acid. Triplet-sensitized photolysis of both isomers results in the formation of Meldrum's acid, the product of a formal reduction of 1 and 2. Mild heating of diazirine 2 produces quantitative yields of diazo Meldrum's acid. The activation parameters for thermal reactions of diazo 1 and diazirino 2 isomers were determined in aqueous and dioxane solutions.
Crystal-to-Gel Transformation Stimulated by a Solid-State E→Z Photoisomerization
Tong, Fei,Chen, Shaolong,Li, Zhiwei,Liu, Mingyue,Al-Kaysi, Rabih O.,Mohideen, Umar,Yin, Yadong,Bardeen, Christopher J.
, p. 15429 - 15434 (2019)
The molecule (E)-(5-(3-anthracen-9-yl-allylidene)-2,2-dimethyl-[1,3] dioxane-4,6-dione) (E-AYAD) undergoes E→Z photoisomerization. In the solid state, this photoisomerization process can initiate a physical transformation of the crystal that is accompanied by a large volume expansion (ca. 10 times), loss of crystallinity, and growth of large pores. This physical change requires approximately 10 % conversion of the E isomer to the Z isomer and results in a gel-like solid with decreased stiffness that still retains its mechanical integrity. The induced porosity allows the expanding gel to engulf superparamagnetic nanoparticles from the surrounding liquid. The trapped superparamagnetic nanoparticles impart a magnetic susceptibility to the gel, allowing it to be moved by a magnetic field. The photoinduced phase transition, starting with a compact crystalline solid instead of a dilute solution, provides a new route for in situ production of functional porous materials.
Rhodium(II)-catalyzed olefin cyclopropanation with the phenyliodonium ylide derived from Meldrum's acid
Mueller, Paul,Allenbach, Yves,Robert, Estelle
, p. 779 - 785 (2003)
The phenyliodonium ylide 3a derived from Meldrum's acid reacts with olefins in the presence of Rh(II) carboxylate catalysts to afford cyclopropanes. The reaction is stereospecific. Enantioselectivities of up to 63% have been observed for the cyclopropanation of pent-1-ene. No 1,3-cycloadducts are formed between 3a and polarized olefins such as furan or 2,3-dihydrofuran.
Chromogenic and fluorogenic chemodosimeter derived from Meldrum's acid detects cyanide and sulfide in aqueous medium
Ferreira, Natasha L.,de Cordova, Letícia M.,Schramm, Adriana D.S.,Nicoleti, Celso R.,Machado, Vanderlei G.
, p. 142 - 153 (2019)
The detection of anionic analytes is of extreme importance since many of these species are toxic and they play a variety of roles in biological, environmental and industrial processes. However, the techniques currently used for their detection are costly and highly complex and thus the search for new detection methods for these analytes is a growing area of scientific research. In this regard, techniques involving the use of molecular and supramolecular devices are being developed, which offer simplicity, precision, reliability and low cost, in both quantitative and qualitative analyses. Herein, a novel compound was synthesized through the Knoevenagel condensation reaction between Meldrum's acid and pyrene–1–carbaldehyde. The final product, 2,2–dimethyl–5–(pyren–1–ylmethylene)–1,3–dioxane–4,6–dione (1), was completely characterized. The performance of compound 1 as a chemodosimeter for the detection of CN? and sulfide was verified. The compound was shown to be simultaneously a selective chromogenic (on–off) and fluorogenic (off–on) chemodosimeter for CN? and sulfide in an organic–aqueous system, with a 1:1 anion:compound stoichiometry. To make the system selective only for CN?, Pb(NO3)2 was added so that all of the sulfide present in the sample precipitated and became unavailable to interact with the chemodosimeter, leaving only the CN? available to react with the system. In all cases the limits of detection were below those established by WHO, with the analytical tests carried out by means of the fluorescence technique allowing the detection of CN? at 10?8 mol L?1. Finally, the system could be used for the detection of CN? spiked in tap water samples.
Method for synthesizing coumarin-3-carboxylic acid compounds by one-pot two-step method
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Paragraph 0053; 0055-0056; 0079; 0081-0083, (2021/06/12)
The invention relates to a method for synthesizing coumarin-3-carboxylic acid compounds by a one-pot two-step method. The structural formula of the coumarin-3-carboxylic acid compounds is shown in the description, wherein R1 is H , Cl , Br, NO2 , CH3 and HO . According to the synthesis process of the coumarin-3-carboxylic acid compounds, malonic acid, acetone and substituted salicylaldehyde serve as raw materials, iodine serves as a catalyst, acetic anhydride serves as a solvent, a series of coumarin-3-carboxylic acid compounds are synthesized through a one-pot cascade reaction, and the efficiency and the yield are greatly improved compared with a fractional step method.
Chemical synthesis, molecular docking and MepA efflux pump inhibitory effect by 1,8-naphthyridines sulfonamides
Oliveira-Tintino, Cícera Datiane de Morais,Tintino, Saulo Relison,Muniz, Débora Feitosa,Rodrigues dos Santos Barbosa, Cristina,Pereira, Raimundo Luiz Silva,Begnini, Iêda Maria,Rebelo, Ricardo Andrade,da Silva, Luiz Everson,Mireski, Sandro Lucio,Nasato, Michele Caroline,Krautler, Maria Isabel Lacowicz,Pereira, Pedro Silvino,Balbino, Tereza Cristina Leal,da Costa, José Galberto Martins,Rodrigues, Fabiola Fernandes Galv?o,Teixeira, Alexandre Magno Rodrigues,Barreto, Humberto Medeiros,de Menezes, Irwin Rose Alencar,Coutinho, Henrique Douglas Melo,da Silva, Teresinha Gon?alves
, (2021/02/26)
This study aimed to evaluate the antibacterial activity and to verify, in silico and in vitro, the inhibition of efflux mechanisms using a series of synthesized 1,8-naphthyridines sulfonamides against Staphylococcus aureus strains carrying MepA efflux pumps. The chemical synthesis occurred through the thermolysis of the Meldrum's acid adduct. The sulfonamide derivatives were obtained by the sulfonylation of 2-amino-5?chloro-1,8-naphthyridine with commercial benzenesulfonyl chloride. Antibacterial activity was assessed by the broth microdilution test. Efflux pump inhibitory capacity was evaluated in silico by molecular docking and in vitro by analyzing synergistic effects on ciprofloxacin and ethidium bromide (EtBr) and by EtBr fluorescence emission assays. The following 1,8-naphthyridines were synthesized: 4-methyl-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10a); 2,5-dichloro-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10b); 4-fluoro-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10c); 2,3,4-trifluoro-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10d); 3-trifluoromethyl-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10e); 4?bromo-2,5-difluoro-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10f). The 1,8-naphthyridines derivatives associated with sulfonamides did not show antibacterial activity. However, they showed a favorable pharmacokinetic profile with possible MepA efflux pump inhibitory action, demonstrated in molecular docking. In addition to the promising results in reducing the concentration of intracellular EtBr. 1,8-naphthyridines act as putative agents in the inhibitory action of the MepA efflux pump.
Properties of a furan ring-opening reaction in aqueous micellar solutions for selective sensing of mesalazine
Sabahi-Agabager, Leila,Eskandari, Habibollah,Nasiri, Farough,Shamkhali, Amir Nasser,Baghi Sefidan, Somayyeh
, (2021/05/04)
A novel and efficient non-azo formation based method was developed for trace sensing of mesalazine (MES), a pharmaceutical aromatic amine. MES was simply coupled with a Meldrum's activated furan (MAF) reagent via a furan ring opening reaction to form a colored product. The intense purple colored solution was detected at 575 nm. The reaction of MES with MAF was monitored by employing 1H NMR spectroscopy and mass spectrometry. In addition, density functional theory (DFT) was applied to optimize the structure of the colored product and its λmax (the wavelength of maximum absorbance) in dimethyl sulfoxide and water. The colored product was considered in three possible structures, and the most possible structures in dimethyl sulfoxide and in water were identified by employing the DFT calculations. Both of the most possible structures indicated only a local excitation in their λmax and no charge transfer was observed. However, one of the structures in dimethyl sulfoxide presented charge transfer properties occurring through N–C[dbnd]C–C moiety. A univariate optimization method was also used to attain the optimum condition for analysis. In addition, the dependence of the analytical response on the three main affecting parameters (reaction time (X1), Triton X-100 concentration (X2) and MAF concentration (X3)) was identified by employing a central composite design (CCD) approach. The CCD study showed that the analytical response depends complexly on the parameters. Beer's law was obeyed within the range of 0.06–9.30 μg mL?1 of MES (155 fold linearity) at 575 nm, under the optimum condition introduced by the CCD approach. Also, the limit of detection was obtained 0.04 μg mL?1 of MES. The method showed precision (as relative standard deviation) and accuracy (as recovery) within the ranges of 0.6–3.2 % and 96.3–100.8%, respectively. Various organic and inorganic species, amino-pharmaceuticals, and amino acids were tested to evaluate the selectivity of the method. The selectivity of the analytical method was satisfactory. The method was successfully applied for detection of MES in various water matrices and pharmaceutical tablets.
Enhancement of anticancer potential of pterostilbene derivative by chalcone hybridization
Chen, Yeh-Long,Chen, Yi-Jin,Hsieh, Ya-Ju,Hsu, Chia-Chi,Ke, Chien-Chih,Tai, Hsiao-Ting,Tang, Kai-Wei,Tseng, Chih-Hua,Tzeng, Cherng-Chyi
, (2021/08/19)
Pterostilbene, a natural metabolite of resveratrol, has been indicated as a potent anticancer molecule. Recently, several pterostilbene derivatives have been reported to exhibit better anticancer activities than that of the parent pterostilbene molecule. In the present study, a series of pterostilbene derivatives were designed and synthesized by the hybridization of pterostilbene, chalcone, and cinnamic acid. The cytotoxic effect of these hybrid molecules was determined using two oral cancer cell lines, HSC-3 and OECM-1. (E)-3-(2-((E)-4-Hydroxystyryl)-4,6-dimethoxyphenyl)-1-(2-methoxyphenyl)prop-2-en-1-one (4d), with IC50 of 16.38 and 18.06 μM against OECM-1 and HSC-3, respectively, was selected for further anticancer mechanism studies. Results indicated that compound 4d effectively inhibited cell proliferation and induced G2/M cell cycle arrest via modulating p21, cyclin B1, and cyclin A2. Compound 4d ultimately induced cell apoptosis by reducing the expression of Bcl-2 and surviving. In addition, cleavage of PARP and caspase-3 were enhanced following the treatment of compound 4d with increased dose. To conclude, a number of pterostilbene derivatives were discovered to possess potent anticancer potentials. Among them, compound 4d was the most active, more active than the parent pterostilbene.
