Khawaja Nasir al-Din Tusi
Department of Chemistry
Department of Chemistry
Khawaja Nasir al-Din Tusi
A series of novel 4-phenylsulfonamido-6-aryl-2-phenylpyrimidine-5-carbonitrile derivatives have been synthesized through a two-step process. This protocol includes a facile surfactant-mediated methodology for the synthesis of 4-amino-6-aryl-2-phenylpyrimidine-5-carbonitrile derivatives through a one-pot, three-component reaction in the presence of a catalytic amount of cetyltrimethylammonium bromide in water. No additional organic solvents and oxidants were used. The pyrimidine-5-carbonitrile products were then subjected to a direct sulfonylation of 4-amino group to 4-phenylsulfonamide-6-aryl-2-phenylpyrimidine-5-carbonitrile derivatives in the presence of sodium hydride in tetrahydrofuran solution. These new structures were confirmed by 1 H- and 13 CNMR spectroscopy as well as mass spectrometry and elemental analyses.
Magnetic a-Fe2O3–MCM-41 mesoporous material functionalized by dual acidic ionic liquid (DAIL) was prepared through a two-step approach as a novel powerful acidic catalyst which provides high ionic media for reactions, by means of post-surface grafting of the mesochannels ofa-Fe2O3–MCM-41 materials with 3-sulfobutyl-1-(3-propyltrimethoxysilane)imidazolium hydrogen sulfate as DAIL. Mesoporous MCM-41 was simply packed on the surface of ferric oxide nanoparticles and DAIL was efficiently incorporated into the mesochannels of MCM-41 generating Lewis and Bro¨nsted acidic sites. The catalyst was characterized by FT-IR, X-ray powder diffraction, HRTEM, vibrating sample magnetometer, X-ray energy diffraction spectra, thermogravimetric and differential thermal analyses, and N2adsorption–desorption measurements. The synthesized hybrid acidic MCM-41 showed good catalytic performance in the one-pot synthesis of pyrimido[4,5-d]pyrimidine derivatives using 6-aminouracil, aldehyde, and urea or thiourea under solvent free conditions. Moreover, it was proved that under this condition, the use of such a hybrid material as a catalyst plays the role of rendering the reactions while neither the a-Fe2O3–MCM-41 nor the 3-methyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate were able to promote this reaction
A novel magnetic MCM-41 nanocomposite-based catalyst is reported for the first time in the multicomponent synthesis of trisubstituted pyrimidines in which piperazine is immobilized inside the mesochannels of magnetic MCM-41 as an organic base (a-Fe2O3-MCM-41-piperazine). This nanocatalyst was thoroughly characterized by various techniques such as FT-IR, XRD, SEM, TEM, EDX and N2-adsorption isotherms. Very uniform dispersion and ordered mesopores ofa-Fe2O3-MCM-41 causes piperazine molecules to be distributed very finely on the internal surface of the pores, resulting in a very useful and robust magnetically recyclable amine-based heterogeneous nanocatalyst. This catalytic system showed remarkable activity in the solvent-free synthesis of 2,4,6-trisubstituted pyrimidine derivatives.
A novel environmentally benign method toward the synthesis of some novel tetrasubstituted 2,4-diaminopyrimidine derivatives using an aqueous glucose-mediated one-pot three-component reaction of malononitrile with various benzaldehyde and amidine derivatives is reported. Some pyrimidine derivatives possessingα-amino acid moiety were synthesized by the present protocol for thefirst time. This protocol offers advantages including facile reaction conditions, using naturally occurring glucose as promoter and water as solvent, simple work-up, relatively short reaction times, and high yields of the products.
Acta Chimica Slovenica Journal Help User Username Password Remember me Notifications View Subscribe Journal Content Search Search Scope Browse By Issue By Author By Title Other Journals Article Tools How to cite item Home About Login Register Search Current Archives Archives (1954 - ) ACSi Main Page ASAP Home > Vol 65, No 3 (2018) > Beyzaei Cover Image Multicomponent Solvent-free Synthesis, Antibacterial Evaluation and QSAR Study of 2-(Bis(benzylthio)methylene)malononitriles Multicomponent reaction of malononitrile, carbon disulphide and various benzyl halides was developed as an efficient strategy for the synthesis of 2-(bis(benzylthio)methylene)malononitrile derivatives via two different procedures: (a) in the presence of K2CO3 as a base in acetonitrile and (b) under solvent-free conditions in the presence of triethylamine. Higher yields with shorter reaction times were obtained from the latter procedure. Inhibitory activity of all derivatives was evaluated against 22 pathogenic bacteria including both Gram-negative and Gram-positive strains. Thioether 4b showed broad-spectrum antibacterial activities according to the antibiogram tests. DFT calculations (B3LYP/6-311++G**) were performed to determine the type of drug–receptor interactions. It was found that reversible dipole–dipole forces play a key role in most interactions.
A facile and efficient catalyst- and oxidant-free multicomponent synthesis of a small library of highly substituted pyrido[2,3-d]pyrimidine derivatives is reported. The products were obtained within relatively short reaction times in good to excellent yields in the presence of deep eutectic solvents as media and promoters. Simple purification and reusability of the deep eutectic solvent were the other beneficial factors of the reported protocol. All of the synthesized derivatives were thoroughly screened for possible in vitro antibacterial and antifungal effects against twenty-two bacterial and three fungal pathogens. Some of the prepared pyrido[2,3-d]pyrimidine derivatives showed remarkable antibacterial and antifungal activities in comparison with some typical known antibacterial and antifungal agents. Finally, the derivatives possessing bioactivity effects were subjected to quantum chemical computational studies in order to reveal the probable structural and electronic effects governing the spotted bioactivities. It was found that the observed bioactivities could be best devoted to the HOMO–LUMO energy gap and para delocalization index of the corresponding derivatives.
Novel N-amino benzylthiolates were synthesized via multicomponent reaction of malononitrile, isothiocyanates and benzyl halides under conventional and solvent-free conditions. Various electron-donating and -withdrawing substitutes within both isothiocyanates and benzyl halides were used to demonstrate the efficiency of new methodology. A broad spectrum of antibacterial and antifungal activities were observed especially within benzyl halides containing electron-withdrawing aryl substituents.
The biological properties of imidazolidine- and tetrahydropyrimidine-2-thione derivatives such as antiviral, antitumor, anti-inflammatory, and analgesic activities increase the demand for mild and efficient synthetic routes. In this regard, methods such as reaction of diaminoalkanes with carbon disulfide have been developed. However, this method usually suffers from relatively long reaction times, using excess reagents, vigorous reaction conditions, and emission of pernicious hydrogen sulfide gas. In this project, MgO nanoparticle was used as an efficient, non-toxic, recyclable, and economic catalyst to synthesize cyclic five- or sixmembered thioureas 3a–h via reaction of 1:1 molar ratios of 1,2- or 1,3-diaminoalkanes 1a–h and carbon disulfide in ethanol at ambient temperature. More interestingly, no hydrogen sulfide emission was detected during the reaction progress. The in vitro antimicrobial properties of synthesized compounds were investigated against 14 different Gram-positive and Gram-negative pathogenic bacteria according to CLSI (Clinical and Laboratory Standards Institute) broth microdilution and disk diffusion methods. The results were compared to those of penicillin, gentamicin, and ceftriaxone, and reported as inhibition zone diameter (IZD), the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) values. The best inhibitory effects were observed with imidazolidine-2-thiones 3c and 3d.
Background Design and synthesis of new inhibitor agents to deal with pathogenic microorganisms is expanding. In this project, an efficient, environmentally friendly, economical, rapid and mild procedure was developed for the synthesis of novel functionalized isoxazole derivatives as antimicrobial potentials. Methods Multicomponent reaction between malononitrile (1), hydroxylamine hydrochloride (2) and different aryl or heteroaryl aldehydes 3a–i afforded novel 5-amino-isoxazole-4-carbonitriles 4a–i in good product yields and short reaction times. Deep eutectic solvent K2CO3/glycerol was used as catalytic reaction media. Structure of all molecules were characterized by different analytical tools. In vitro inhibitory activity of all derivatives was evaluated against a variety of pathogenic bacteria including both Gram-negative and Gram-positive strains as well as some fungi. In addition, their free radical scavenging activities were assessed against DPPH. Results Broad-spectrum antimicrobial activities were observed with isoxazoles 4a, b, d. In addition, antioxidant activity of isoxazole 4i was proven on DPPH. Conclusions In this project, compounds 4a, b, d could efficiently inhibit the growth of various bacterial and fungal pathogens. Antioxidant properties of derivative 4i were also significant. These biologically active compounds are suitable candidates to synthesize new prodrugs and drugs due to the presence of different functional groups on their rings.
The synthesis of pyrazolo[3,4-d]pyrimidine derivatives is important due to their presence in various biologically active compounds such as anticancer, antimicrobial, antiparasitic, anti-inflammatory and antidiabetic agents. In this project, a new and efficient approach for the synthesis of some novel 4-imino-5H-pyrazolo[3,4-d]pyrimidin-5-amines from reaction of 5-amino-pyrazole-4-carbonitrile with various hydrazides in ethanolic sodium ethoxide medium was reported. Antimicrobial activities of all synthesized derivatives were evaluated against eight Gram-positive and five Gram-negative pathogenic bacteria. The moderate to good inhibitory effects were observed based on inhibition zone diameter (IZD), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. In order to determine the reasonable relationship between antibacterial activities and physiochemical properties of the derivatives, computational studies were carried out in terms of geometry optimization, short-range van der Waals forces, dipole moments, atomic charges and frontier orbital energies. It was found that both short-range forces and covalent bonds are important in the observed inhibitory effects of the molecules. The results suggested that pyrazolo[3,4-d]pyrimidine derivatives prefer a soft nucleophilic attack on bio-macromolecular targets. Furthermore, our models proposed that the antibacterial activities of these derivatives can be improved by substituting large electron donating groups on the 6-phenyl rings.
An efficient procedure was proposed for the synthesis of 3(5)-substituted 1,2,4-triazol-5(3)-amines via a one-pot reaction of thiourea, dimethyl sulfate and various hydrazides. 1,2,4-Triazole derivatives were prepared in aqueous media under mild conditions while adhering to some principles of green chemistry. The products were easily isolated in 83–95% yields without any need for further purifcation. Inhibitory activities of all synthetic compounds were assessed against a variety of Gram-positive and Gram-negative pathogenic bacteria as well as some fungal pathogens. The best antibacterial efects were observed with 3(5)-phenyl-1H-1,2,4-triazol-5(3)-amine according to its MIC values (4–8 μg mL−1). All compounds were successful in blocking the growth of fungi. Acceptable antioxidant properties were observed only with 3(5)-(4-nitrophenyl)-1H-1,2,4-triazol-5(3)-amine.
Background: Design, identifcation, and synthesis of new antimicrobial agents along with preventive proceedings are essential to confront antibiotic-resistant pathogenic bacteria. Heterocyclic Schiff bases are biologically important compounds whose antimicrobial potentials have been proven to bacterial and fungal pathogens. Objectives: In this study, some quinoline Schiff bases were synthesized from condensation of 2-chloro- 3-quinolinecarboxaldehyde and aniline derivatives. Their inhibitory activities were evaluated against 6 gram-positive and 2 gram-negative bacterial pathogens. Methods: Disc diffusion, broth microdilution, and time-kill tests were applied according to the CLSI guidelines to determine IZD, MIC, and MBC values. Results: 2-Chloro-3-quinolinecarboxaldehyde Schiff bases could inhibit the growth of bacteria with IZDs of 7.5-19.8 mm, MICs of 256-2048 μg mL-1, and MBCs of 512 to ≥2048 μg mL-1. Conclusion: Moderate antibacterial effects were observed with heterocyclic Schiff bases. Complexation and structural changes can improve their antimicrobial properties.
There is a growing need for new antibiotics and antifungal drugs to combat pathogenic bacteria and fungi. In order to develop potential antimicrobial agents, some 1,2,4-triazole-3-thiones were synthesized from the reaction of hydrazides with isothiocyanates under optimized conditions in deep eutectic solvent of potassium carbonate-glycerol (1:5 M ratio). Blocking properties of all products were assessed on a variety of Gram-positive and Gram-negative bacterial as well as fungal pathogens. Good to excellent inhibitory effects especially against fungi were observed with all synthesized compounds. 5-(4- Hydroxyphenyl)-4-(4-nitrophenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (3b) showed significant antioxidant activity according to the results obtained from 2,2-diphenyl-1-picrylhydrazylf (DPPH) free radical scavenging experiments. The possible interaction mechanism of synthetic triazoles with 1IYL enzyme on Aspergillus fumigatus was investigated by molecular docking method. A complete agreement was found between experimental data and theoretical calculations. Hydrogen bond acceptor strength of N-1 in 1,2,4-triazole rings was the main cause of the observed differences.
An eco-friendly and simple procedure was proposed for the synthesis of 3,5-disubstituted 1,2,4-triazoles by optimized reaction of benzamidine hydrochloride and various aryl hydrazides. H2O and K2CO3 were applied as green and available solvent and base, respectively. The products were generated in good to high yields in one step and sufficient purity after a simple workup. The designed process is applicable to other organic syntheses especially from poorly water-soluble reactants such as hydrazines or hydrazides. Inhibitory activity of all prepared derivatives was evaluated against 10 pathogenic bacteria strains including both Gram-positive and Gram-negative, as well as 2 mold and 1 yeast strains. The prepared derivatives showed good antimicrobial activities. 1,2,4-Triazoles containing 2-hydroxynaphthalen-3-yl and 5-chlorothiophen-2-yl substituents at position 3 showed the best antifungal and antibacterial properties, respectively.
One of the goals of green chemistry is to use environmentally friendly solvents or remove and reduce the volume of harm-ful spent solvents. In this study, a novel process for the synthesis of 5-substituted 1,3,4-oxadiazole-2-thiol derivatives was proposed via ultrasound-assisted reaction of aryl hydrazides with CS2 (1:1 molar ratio) in some drops of DMF in the absence of basic or acidic catalysts. They were produced in good to excellent yields under easy workup and purification conditions. In order to prove the usefulness of the prepared compounds, their antioxidant, antibacterial, and antifungal potentials were screened by DPPH free radical scavenging, serial twofold microdilution and streak plate methods. Acceptable to significant inhibitory activities were observed with synthesized heterocycles. The results showed that 5-(4-fluorophenyl)-1,3,4-oxa-diazole-2-thiol (3c) is an broad-spectrum antimicrobial agent. Many of them displayed remarkable antioxidant properties comparable to standard controls (ascorbic acid and α-tocopherol). Synthesized 1,3,4-oxadiazoles are also potent candidates to treat cancer, Parkinson, inflammatory, and diabetes diseases.
A series of three novel nanocomposites were prepared by modifying the surface of natural clinoptilolite using various amounts of manganese ferrite (MnFe2O4) nanoparticles. These manganese ferrite-modified nanocomposites (MFO–NC) were fully characterized by XRD, FT-IR, EDX, VSM and TEM analyses. One of these novel nanocomposites with 40 wt% of manganese ferrite in clinoptilolite (MFO–NC-3) showed a strong catalytic behavior in the aldol-type Claisen–Schmidt reaction for the synthesis of chalcones. A strong catalytic synergy was observed between nano-MnFe2O4 particles and natural clinoptilolite in the structure of these nanocomposites. The products with a broad range of substituents on the reactants were efficiently obtained under room-temperature conditions within relatively short reaction times with good to excellent yields in the presence of one of the prepared MFO–NC nanocomposites. This nanocomposite also showed a strong stability and substantial reusability in the synthesis of chalcones.
1,2,4-Triazoles are biologically active compounds which prepared via a variety of synthetic methods . Some multicomponent and one-pot procedures were also developed for their preparation. Deep eutectic solvents (DESs) as environmentally friendly solvents were widely applied in different chemical processes [2, 3]. As part of our current studies on the development of new routes in organic synthesis, we report an efficient and green procedure for the synthesis of functionalized 1,2,4-triazoles-3-thione derivatives under optimized conditions via reaction of aryl hydrazides and alkyl or aryl isothiocyanates (fig. 1). Glycerol/potassium carbonate was used as catalyst and reaction media. 1,2,4-Triazoles-3-thione derivatives were obtained in very good yields without the need for additional purification steps.
Fused pyrimidine derivatives have participated in the structure of various medicinally significant compounds especially as the privileged motifs for anticancer agent’s design purposes . Among fused pyrimidine derivatives, pyrido [2,3-d]pyrimidines have been the subject of study in recent years for their diverse bioactivity effects [2, 3]. In the present study, some novel pyrido [2,3-d]pyrimidine derivatives were synthesized through a green and efficient multicomponent procedure in the presence of a novel prepared LDH modified Clinoptilolite nanocatalyst. 4(6)-Aminouracil derivative, malononitrile, benzaldeyhyde derivatives were used as starting materials in the presence of the designed nanocatalysts in DMF as medium. This protocol has been previously reported under several reaction conditions . The reactions were carried out smoothly and the products were obtained with good to excellent yields within relative short reaction times. The nanocatalyst was easily separated by centrifugation from the reaction mixture. The products were simply obtained by aqueous dilution of the organic layer and washed with hot ethanol whenever necessary.
Triazoles are an important class of five-membered aromatic heterocycles containing three nitrogen atoms. They are contained in two resonance forms . The triazole ring system is found in a variety of naturally occurring compounds and biologically active molecules . They are used in medicine as antifungal agents . The resistance of bacteria and fungi to antibiotics is still increasing and can be a serious threat to human health in the future. New antimicrobial agents must be designed and identified to confront these pathogens. In this study, 1,2,4-triazole derivatives were obtained via reaction of benzamidine and hydrazides in the presence of K2CO3 in water (Fig. 1). The molecular structure of all synthesized compounds were characterized with IR, 1H NMR, 13C NMR spectra. Finally, the inhibitory effect of the synthesized derivatives has been investigated on several Gram-positive and Gram-negative bacteria and pathogenic fungi. The result of this study showed that triazole compounds are potential antibacterial and antifungal agents due to their significant inhibitory effects.