Chemistry Journal of Moldova

https://doi.org/10.19261/cjm.2024.1135

Abstract (PDF)
Supplementary Material (PDF)
Graphical Abstract: This study presents an eco-friendly method for synthesizing 3,4-dihydropyrimidin-2(1H)-ones (DHPMs) through the Biginelli reaction. A novel Heteropolyacid-Clay (HPA-Clay) catalyst, formed by immobilizing H5PV2W10O40 on Montmorillonite KSF clay, displays enhanced stability and catalytic efficiency. Operating under solvent-free, one-pot conditions, the process delivers DHPMs with high yields and shortened reaction times. Catalyzed by 2 mol% HPA-Clay, it adheres to green chemistry principles, emphasizing cost-efficiency, environmental sustainability, and recyclability. The catalyst consistently performs over multiple cycles, showcasing promise for advancing Biginelli reactions.

 

Abstract (PDF)
Supplementary Material (PDF) 

Graphical Abstract: A green and efficient method for the multicomponent synthesis of 3,4-dihydropyrimidin-2(1H)-ones and -thiones using acetic acid supported on activated charcoal as a mild acid catalyst in ethanol under both conventional as well as microwave irradiation conditions has been developed. The catalyst system found more efficient under microwave irradiation conditions than conventional conditions with shorter reaction times and excellent yields.


 

https://doi.org/10.19261/cjm.2022.892   

Abstract (PDF)
Supplementary Material (PDF)  

Graphical Abstract: Herein, an efficient one-pot synthesis is described, of substituted benzimidazole derivatives (3a-j) from a condensation of various o-phenylenediamine (1a-j) aromatic aldehyde (2a-j) using ZnFe₂O₄ as a nano-catalyst under ultrasonic irradiation conditions. All forms of aldehydes with an electron releasing or electron –withdrawing substituent have a significant yield. The catalyst can easily be recovered after completion of the reaction and reused without affecting its activity. Prepared benzimidazole derivatives showed moderate to good anti-tuberculosis results.


 

https://doi.org/10.19261/cjm.2022.895   

 

Abstract (PDF)
Graphical Abstract: A facile, one-pot, and solvent-free synthesis was developed to obtain a thermally stable chitosan biopolymer. The bifunctional isocyanate by interaction with chitosan formed urea and urethane bonds between chitosan chains. Subsequently, the designed chemistry facilitated the formation of carbodiimide bonds between chitosan chains via dehydration of the urea bond. The modified chitosan was proved to be superior in thermal properties and could be used as a thermally stable bio-filler. This synthetic methodology is a facile route to achieve improved thermal stability in biopolymers.

https://doi.org/10.19261/cjm.2021.864   

 

Abstract (PDF)
Graphical Abstract: In this work, the stereospecific synthesis of optically active cis β-lactams under diverse microwave-induced conditions using diverse solvents was reported. The effects of low tanδ values of the solvents are found to be more crucial than solvents with high dipole moments and dielectric constants. The results indicated that for the synthesis of β-lactams solvents with low tanδ and high dipole moment and high dielectric constant are necessary. Best of the knowledge this is the first report that examined the importance of tanδ values of the solvents in β-lactams synthesis.

DOI: https://doi.org/10.19261/cjm.2020.774

Abstract (PDF)
Graphical Abstract: The present paper shows that lanthanum(III) nitrate hexahydrate can be used as mild and environment friendly homogeneous catalyst for an efficient one-pot multi-component synthesis of biologically active 1,8-dioxo-octahydroxanthene and 14H-dibenzo[a,j]xanthene derivatives. The solvent free condensation reaction of aromatic aldehydes and dimedone or β-naphthol was carried out at 70-80ºC during 10-30 min. The advantages of this eco-friendly synthesis route are numerous, and include the use of an inexpensive catalyst, high to excellent yield, short reaction time and high catalytic activity that can make this method an interesting alternative to multi-step approaches.


 

 

 

DOI: https://doi.org/10.19261/cjm.2020.695   

Abstract (PDF) 

Graphical Abstract: The research is devoted to the study of unexpected products that formed as a result of the condensation reaction between 2-acetylpyridine and 2-formylpyridine under the Claisen-Schmidt reaction conditions. As a result, a sequence of reactions leading to the following compounds has been proposed: 1,3-bis (pyridin-2-yl) prop-2-en-1-one (3); 1,3,5-tri (pyridin-2-yl) pentane-1,5-dione (4); (2,4-dihydroxy-2,4,6-tri(pyridin-2-yl)cyclohexyl)(pyridin-2-yl)methanone (5) and (4-hydroxy-2,4,6-tri(pyridin-2-yl)cyclohexane-1,3-diyl)bis(pyridin-2-ylmethanone) (6) as well as 2-formylpyridine (1) and 2-acetylpyridine (2). The plausible mechanism of these chemical transformations has been proposed. All the obtained compounds demonstrate moderate antimicrobial, antifungal and antioxidant activity.


 

DOI: https://doi.org/10.19261/cjm.2019.657   

Abstract (PDF)
Graphical Abstract: This study describes the preparation of two bicyclo[3.3.3]nonane-steroid derivatives from either estradiol or estrone using some reactions such as etherification, addition, nucleophilic substitution and cyclization. The chemical structure was evaluated through NMR spectroscopic analysis. The results showed higher yield for 11 compared with 12. It is noteworthy that the reagents used in this investigation are not expensive and do not require special conditions for handling.


 

DOI: https://doi.org/10.19261/cjm.2019.647   

Abstract (PDF) 

Graphical Abstract: A series of novel isolated β-lactams 3a-c and thiazolidinone derivatives 4a-c were successfully synthesized from reactions of new Schiff's bases 2a-c with chloroacetyl chloride and thioglycolic acid. The antimicrobial activity of the obtained compounds was assessed in vitro against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria and Aspergillus flavus and Candida albicans fungi. Furthermore, a molecular docking study was carried out and the results indicated that compounds 3b and 4b displayed comparable binding affinity scores as that of glutamate. These two compounds are promising candidates as antibacterial and antifungal agents that would deserve further investigations.