Metal triflate-catalyzed acylation of sulfonamides and direct transacylation of N-acylsulfonamides have been investigated. The acylation of sulfonamides proceeds efficiently in the presence of a catalytic amount of Cu(OTf)2 (0.001 equiv) using either carboxylic anhydrides or acyl chlorides as the acylating agents. Alternative catalysts suitable for this transformation include Al(OTf)3, Fe(OTf)3, Ga(OTf)3, In(OTf)3, and Er(OTf)3. In the presence of Cu(OTf)2 (0.2 equiv), N-acylsulfonamides undergo direct transacylation in excess acyl chlorides (10 equiv) to furnish new N-acylsulfonamides through exchange of N-acyl groups. Ga(OTf)3, Fe(OTf)3, and In(OTf)3 are similarly reactive in catalyzing such transacylation transformations. The reaction conditions are mild and operationally convenient. A variety of functional groups including halogeno, keto, nitro, cyano, ether, and carboxylic ester are tolerated, providing the corresponding monoacylated N-acylsulfonamides in good to excellent yields.
A convenient synthetic protocol for diverse 4, 5-disubstituted-6-methyl-2-(methylthio)pyrimidines was successfully developed by Sonogashira reactions. In the presence of Pd-Cu catalysts, one-pot, multi-step reaction of amines, terminal alkynes, and 4-chloro-5-iodo-6-methyl-2-(methylthio)pyrimidine in DMF at 80°C resulted in 4, 5-disubstituted-6-methyl-2-(methylthio)pyrimidine derivatives in moderate to good yields.
A potassium 4-(ethoxycarbonyl)phenyldithiocarbamate, (4-etphdtc), and 6-ethoxybenzothiazol)-dithiocarbamate, (6-etbedtc), ligands have been isolated and four metal dithiocarbamate complexes of the type [M(4-etphdtc)2] and [M(6-etbedtc)2] (M = Zn, Cd;) were synthesized and characterized by elemental analysis and spectroscopic techniques (FT-IR,1H and13C{1H}-NMR, HRMS, UV–vis). Thermogravimetric studies of all four complexes were performed and the final product of the thermal decomposition was metal sulfides. The theoretical study with density functional theory (DFT) has been utilized to optimize the structures of the complexes for HOMO–LUMO energy calculation. Non-bonding orbitals (NBO) analysis was performed to determine the numerous hyper-conjugative interactions responsible for the stability of the compound. In addition, Molecular Electrostatic Potential (MEP) analysis was conducted to identify the compounds’ electron-rich, electron-poor, reactive sites, and bonding characteristics. The Electron Localization Function (ELF), and AIM Charges are also calculated. In vitro cytotoxicity, the complexes were examined against cervical cancer cells (HeLa) to assess their reactivity. Molecular docking studies were conducted to confirm the biological activity by simulating the binding orientation and affinity of the ligands and their complexes against VEGFR-2 kinase, The investigated ligands interact with the binding site as; hydrophilic (Lys868, Glu885, His1026, Cys1045, and Asp1046) and hydrophobic (Val889 and Leu889) for 4-etphdtc; hydrophilic (Lys868, Glu885, Cys1045, and Asp1046) and hydrophobic (Val889, Leu889, Leu1035, and Phe1047) for 6-etphdtc. The calculated binding free energy values for Zn(4-etphdtc)2 and Zn(6-etphdtc)2complexes are – 9.700 kcal/mol, – 10.003 kcal/mol, respectively.
A simple synthetic strategy to construction of novel 4-oxo-2-phenyl-4H-chromene-3-carbothioamides (2–6) was achieved. The synthetic strategy depended on the treatment of 1-(2-hydroxyphenyl)-3-phenylpropane-1,3-dione (1) with some examples of aryl, aralkyl, aroyl and phosphorus isothiocyanates with promotion of DBU. The interesting 4,6-diphenyl-5-(2-hydroxy-benzoyl)-2-thioxo-3,4-dihydro-2H-1,3,4-oxazaphosphinine (8) as a highly regioselective product was obtained through treatment of the substrate 1 with phenyl phosphonisothiocyanatidous chloride whereas the other novel 2-phenyl-3-(2-thioxo-2H-1,3,5,4-thiadiazaphosphinin-6-yl)-4-oxo-4H-chromenes (9 and 10) were formed by using phosphorous diisothiocyanate and triisothiocyanate, respectively, under the same basic reaction conditions. All the reaction mechanisms were discussed. Structures of all the synthesized products were established by elemental analysis and available spectral tools.
Thiazole derivatives have long been a hot topic in pharmaceutical research and remain among the greatest active fields in heterocyclic chemistry. Thiazole derivatives, as one of the potentially favored structure, have been extensively desirable by industrial and medicinal researchers and have gained significant success in the previous decades due to their various biological activities, such as anticancer, antibacterial, antifungal, anti-HIV, antiulcer, and anti-inflammatory activity. In addition, many thiazole drugs are well-known pharmaceuticals on the market.
This review summarizes the freshly synthesized routes and prospective biological activities of thiazole derivatives. In addition, it highlights thiazoles as treatment drugs in clinical trials or approved by the FDA and spotlights on some of their industrial applications. On the other hand, one of the goals of this review is to open up prospects for the future design, development, and usage of thiazole derivatives as potent drugs.
A new cadmium complex with a flexible imidazolinethione ligand has been successfully synthesized. The ligand acts as a bidentate chelating molecule, resulting in the structure being a monomer. In this monomer, cadmium has an octahedral geometry coordinated by four sulfur atoms from two mbit ligands where mbit = 3,3'-methylenebis(1-methyl-1,3-dihydro-2H-imidazole-2-thione) and two oxygen atoms from the DMF molecules. The anions are uncoordinated and neutralize the positive charge of the cationic complex. The title complex has a good capacity for adsorbing several organic dyes from pollutant solutions.
This article reports an efficient and practical microwave-assisted MMPP-promoted synthesis of novel pyrazolyl sulfones from the corresponding 4-(alkyl/cycloalkylthio)-1H-pyrazoles. The reaction of 4-(alkyl/cycloalkylthio)-1H-pyrazoles with magnesium bis(monoperoxyphthalate)hexahydrate (MMPP) as an oxidizing agent afforded the corresponding 4-(alkyl/cycloalkylsulfonyl)-1,3-disubstituted-1H-pyrazoles in 85–95% yield. This method's benefits include its straightforward operation, simple workup, and use of an inexpensive, halogen-free MMPP oxidant that is easy to use and reasonably stable. All synthesized pyrazolyl sulfones were examined against bacterial and fungal strains, and notable antimicrobial activity was demonstrated by a few of the compounds. In order to investigate the prospect of connecting compounds with the highest yield and antimicrobial activity with their opto-electronic properties, time-resolved photoluminescence investigations for compounds 5a, 5b, and 5d were conducted. The tunable spectrum was observed in the micro-second time domain in all three cases, with fluorescent lifetime found higher in the compound having methyl group, intermediate with phenyl group, and lowest with the p-nitrophenyl group. Our procedures will encourage additional research into the valuable properties of pyrazolyl sulfones now that they are widely available with the structural complexity illustrated here.
Heterocyclic systems containing 2-(2-hydrazinyl) thiazole moieties were synthesized by heterocyclization of thiosemicarbazones with arylglyoxals and Meldrum's acid in ethanol and water 1:1 (v/v) under reflux conditions. The paper reports an efficient, facile, and environmentally friendly protocol via a novel one-pot three-component reaction to access a broad range of 2-(2-Hydrazinyl) thiazole derivatives. Products were isolated by plate chromatography and their structures were established from their spectroscopic data, then the antibacterial and antioxidant activity of synthesized 2-(2-hydrazinyl) thiazole derivatives were evaluated, and demonstrated encouraging antibacterial activity against Staphylococcus aureus as a gram positive bacteria and Escherichia coli as a gram negative bacteria. Furthermore, when representative products were assessed for radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH0), high antioxidant effects were observed, indicating their potential safety for use in pharmacological studies.