Microwave-assisted synthesis of bipyrazolyls and pyrazolyl-substituted pyrimidines

We describe the preparation of 1,4′-bipyrazolyls and 4-pyrazolylpyrimidines by the reaction of 2-pyrazolyl-3-dimethylamino acrylate and acrylonitrile with double nucleophilic reagents such as hydrazines, urea and guanidine. Reactions were performed under microwave irradiation in 5-60 min. This is a useful procedure for the preparation of valuable compounds with applications in medicinal and coordination chemistry.     

Microwave-assisted synthesis of pyrazole-based 1,2,3-triazole derivatives and evaluation of their antimicrobial activity

Russian Journal of General Chemistry - A series of new pyrazole-based 1,2,3-triazole derivatives were synthesized through the microwave-assisted Huisgen click reaction from...     

Synthesis of N-methylpiperidin-4-one derivatives and evaluation of their anti-endometrial cancer activity

Russian Journal of General Chemistry - Four novel N-methylpiperidin-4-one derivatives were synthesized and characterized by IR, 1H NMR, HRMS, and single crystal X-ray crystallography. The...     

Microwave-assisted synthesis of 5-aryl-3-hydroxy-2-oxindole derivatives and evaluation of their antiglaucomic activity

A set of new 5-aryl-3-hydroxy-2-oxindoles was synthesized by decarboxylative condensation of the corresponding 5-aryl-substituted isatins with malonic or cyanoacetic acids under microwave irradiation. The antiglaucomic activity of the obtained compounds was evaluated. The most water soluble compounds can reduce the intraocular pressure (IOP) up to 2 Torr.     

Synthesis of 2-oxo/thioxooctahydroquinazolin-5-one derivatives and their evaluation as anticancer agents

An environment friendly method for the synthesis of 2-oxo/thioxooctahydroquinazolin-5-one derivatives has been devised using Ceric ammonium nitrate (CAN) as catalyst and polyethylene glycol (PEG) as solvent. The cytotoxic effect of these compounds was studied on U87 human glioma cells, compounds 4c, 4d and 4e are found to exhibit excellent activity at a concentration as low as 0.06 μg/ml.     

Synthesis of some 5-arylidene-2-(4-acetamidophenylimino)-thiazolidin-4-one derivatives and exploring their breast anticancer activity

Ten 2-(4-acetamidophenylimino)-5-arylidenethiazolidin-4-one derivatives 6a-k were synthesized and evaluated for their anticancer activity against MCF-7 cell line (breast adenocarcinoma). The synthetic approach involves cyclocondensation of N,N′-bis(4-acetamidophenyl)-thiourea (3) with ethyl bromoacetate in ethanol and sodium acetate to furnish the 2-(4-acetamidophenylimino)-4-thiazolidinone derivative 4 , which underwent Knoevenagel condensation reaction with some substituted aldehydes to afford the targeted 2-(4-acetamidophenylimino)-5-arylidenethiazolidin-4-ones 6a - k . The 4-chlorobenzylidene-thiazolidin-4-one compound 6h exhibited strong inhibitory effect on the growth of breast cancer cell with IC₅₀ (58.33 ± 1.74μM), very close to that of the reference drug doxorubicin (IC₅₀ 48.06 ± 0.36μM).     

Microwave-assisted one-pot synthesis of octahydroquinazolinone derivatives using ammonium metavanadate under solvent-free condition

Ammonium metavanadate (NH₄VO₃) has been shown to be an inexpensive, efficient, and mild catalyst for the one-pot synthesis of octahydroquinazolinone derivatives using dimedone, urea/thiourea, and appropriate aromatic aldehydes under microwave-irradiation.     

Microwave-assisted synthesis and antibacterial activity of some pyrazol-1-ylquinoxalin- 2(1H)-one derivatives

3-Hydrazinoquinoxalin-2(1H)-one was prepared from quinoxaline-2,3-dione and subsequently used for the synthesis of some potentially biologically active 3-(pyrazol-1-yl)quinoxalin-2(1H)-one derivatives. While 3-(3,5-dimethylpyrazol-1-yl)quinoxalin-2(1H)-one showed a comparative effect with streptomycin, 3-(5-oxo-3-phenyl-4,5-di- hydropyrazol-1-yl)quinoxalin-2(1H)-one was found to be the most active with an MIC value of 7.8 μg/ml.     

Design,synthesis and antifungal activity of novel selenochroman-4-one derivatives

A series of novel selenochroman-4-one derivatives bearing semicarbazone or nitrogen heterocycle was designed, synthesized, tested antifungal activity and characterized via ¹H-NMR, ¹³C-NMR, and HRMS. The design of the compounds is based on the principle of molecule hybrid and bioisosterism. We aimed at attaching semicarbazones or nitrogen heterocycle to the selenochroman-4-one for enhancing antifungal activity. The antifungal activity of target compounds was evaluated using the microdilution broth method in vitro test. Bioassay results indicated that some of the derivatives displayed good fungistatic activity on Candida zeylanoides, Candida albicans, Cryptococcus neoformans, resistant to fluconazole strain 103 (Candida albicans), resistant to fluconazole strain 100 (Candida albicans) and strain SC5314 (Candida albicans). All the compounds exhibit antifungal activities against the tested funguses in different levels, among them, 7 compounds of antifungal activity against several funguses is better than that of the control drug fluconazole. Based on the results, preliminary structure activity relationships (SARs) were summarized to serve as a foundation for further investigation.     

Microwave-assisted synthesis of dinucleoside analogues containing a thiazolidin-4-one linkage via one-pot tandem Staudinger/aza-Wittig/cyclization

Dinucleosides containing a thiazolidin-4-one linkage were prepared by one-pot tandem Staudinger/aza-Wittig/intermolecular cyclization under microwave irradiation and their structures were confirmed. Preliminary examination of HIV-RT inhibition showed that the dinucleosides containing (R)-thiazolidin-4-one linkage are significantly more active than those containing (S)-thiazolidin-4-one linkage.     

Microwave-assisted,rapid synthesis of 2-vinylquinolines and evaluation of their antimalarial activity

A rapid and efficient synthesis of 2-vinylquinolines via trifluoromethanesulfonamide-mediated olefination of 2-methylquinoline and aldehyde under microwave irradiation is reported. Biological evaluation of these scaffolds demonstrates that 2-vinylquinolines 3x-3z possess excellent antimalarial activities against chloroquine-resistant Dd2 strain of Plasmodium falciparum (IC₅₀ < 100 nM).     

Microwave-assisted three component one-pot synthesis of pyrimido-oxazepines

A synthetic approach toward pyrimido-oxazepine analogs was developed through the use of microwave heating. Certain analogs can be made in one step, which make this a valuable tool in the investigation of this therapeutically relevant scaffold.     

Microwave-assisted synthesis of novel fluorinated 1,2,4-triazole derivatives,and study of their biological activity

Microwave irradiation was used for synthesis of a series of novel fluorinated 1,2,4-triazole derivatives. The molecular structures of the compounds were determined by use of ¹H NMR and FTIR spectroscopy and MS and HRMS. Study of their biological activity showed most of the compounds had good herbicidal activity.     

Microwave-assisted synthesis of novel bis(2-thioxothiazolidin-4-one) derivatives as potential GSK-3 inhibitors

(5Z,5′Z)-3,3′-(1,4-Phenylenebis(methylene)-bis-(5-arylidene-2-thioxothiazolidin-4-one) derivatives (5a-r) have been synthesized by the condensation reaction of 3,3′-(1,4- or 1,3-phenylenebis(methylene))bis(2-thioxothiazolidin-4-ones) (3a,b) with suitably substituted aldehydes (4a-f) or 2-(1H-indol-3-yl)2-oxoacetaldehydes (8a-c) under microwave conditions. The bis(2-thioxothiazolidin-4-ones) were prepared from the corresponding primary alkyl amines (1a,b) and di-(carboxymethyl)-trithiocarbonyl (2). The 2-(1H-indol-3-yl)-2-oxoacetaldehydes (8a-c) were synthesized from the corresponding acid chlorides (7a-c) using HSnBu₃.     

Synthesis of 1,2,3-benzotriazin-4-one derivatives containing spirocyclic indoline-2-one moieties and their nematicidal evaluation

To discover new chemotypes of nematicides with proper toxicological profiles, a series of novel 1,2,3- benzotriazin-4-one derivatives were synthesized and further bioevaluated. The bioassay results showed that most of the synthesized compounds were endowed with moderate to good control efficacy against Meloidogyne incognita at 10.0 mg/L in vivo. Among them, compounds 6k and 6p displayed 100% inhibitory activities at this concentration, which implied that they could be used as lead compounds for promising nematicides.     

Microwave-assisted one-pot synthesis of 2,3-disubstituted 3H-quinazolin-4-ones

A practical synthesis of 2,3-disubstituted 3H-quinazolin-4-ones 1 with broad chemistry scope is described. The key step is the microwave promoted one-pot, two-step reaction sequence combining anthranilic acids, carboxylic acids, and amines providing efficient access to this important class of heterocycles.     

Microwave-assisted synthesis of borneol esters and their antimicrobial activity

Seventeen borneol esters (1–17) were synthesised by conventional and microwave-assisted methodology using DIC/DMAP, and seven are described for the first time (8, 9, 10, 12, 13, 16 and 17). The microwave-assisted methodology was carried out without use of solvents, displayed short reaction times, and showed equal or higher yields for all the long-chain esters and three aromatic compounds (11, 12 and 14) when compared to the conventional approach. All the borneol esters were evaluated against the bacteria Streptococcus sanguinis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and the fungus Candida albicans. Compounds 12, 13 and 14 displayed promising antibacterial activity with a MIC equal to ampicilin (62.5 mg mL^?1) for some microorganisms. In fact, bornyl 3′,4′-dimethoxybenzoate (13) was active against all tested bacteria and fungus.