Synthesis and Antimicrobial Evaluation of Novel Pyrazole, Imidazole and Pyrimidine Derivatives Possessing Imidazo[4,5-b]indol Moiety

In this study, novel pyrazole, imidazole, pyrimidine derivatives bearing imidazo[4,5-b]indol moiety were successfully synthesized and their chemical structures were identified and confirmed by different spectral techniques. All the synthesized compounds were tested against four bacterial strains (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) and two fungi (Aspergillus flavus and Candida albicans). The obtained results show that the synthesized compounds could find fruitful applications as antibacterial and antifungal agents in pharmaceutical chemistry

Novel Β-lactams and Thiazolidinone Derivatives from 1,4-dihydroquinoxaline Schiff’s Base: Synthesis, Antimicrobial Activity and Molecular Docking Studies

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 chemical structures of the new compounds were confirmed through different spectroscopic techniques including IR, 1H NMR, 13C NMR, mass spectrometry and elemental analysis. 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

Synthesis of some new spirocyclic β-lactam and spirocyclic thiazolidin-4-one derivatives

Selective oxidation of 4-amino-2-methyl-5,10-dioxo-1,5,10,10a-tetrahydrobenzo[g]-quinoline-3-carbonitrile (1) with selenium dioxide provided, 4-amino-2-formyl-5,10-dioxo-1,5,10,10a-tetrahydrobenzo[g]quinoline-3-carbonitrile (2). The one-pot reaction of compound 2 with ethyl cyanoacetate and thiourea in ethanol yielded 4-amino-2-(5-cyano-6-oxo-2-thioxo-1,2,3,6-tetrahydropyrimidin-4-yl)-5,10-dioxo-1,5,10,10a-tetrahydrobenzo[g]-quinoline-3-carbonitrile (3). The cycloaddition reaction of chloroacetic acid with compound 3 yielded 7-(4-amino-3-cyano-5,10-dioxo-1,5,10,10a-tetrahydrobenzo-[g]quinolin-2-yl)-3,5-dioxo-3,5-dihydro-2H-thiazolo[3,2-a]pyrimidine-6-carbonitrile (4). Moreover, Ehrlich-Sachs condensation reaction of compound 4 with the aromatic nitroso compounds 5a-c gave the corresponding new Schiff bases 6a-c. Staudinger's ketene-imine cycloaddition reaction of compounds 6a-c with chloroacetyl chloride afforded the corresponding spiro[chloroazetidinethiazolopyrimidine] derivatives, 7a-c. On the otherhand, cycoladdition reaction of thioglycolic acid with Schiff bases 6a-c yielded the corresponding spiro[thiazolidinethiazolopyrimidine] derivatives, 8a-c. Structures of the new compounds were elucidated by compatible analytical and spectroscopic (IR, 1H NMR and MS) measurements. Moreover, the reaction mechanisms that account for formation of the synthesized compounds have been discussed

Synthesis and studies molecular docking of some new thioxobenzo[g]pteridine derivatives and 1,4-dihydroquinoxaline derivatives with glycosidic moiety

The present work is mainly dedicated to heterocyclic compounds as well as S-glycoside. 1,4-dihydroquinoxaline derivatives 3 were obtained from the reaction 2 with carbon disulfide in presence of potassium hydroxide. S-glycoside 4 was prepared from the reaction of compound 3 with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide. Several heterocyclic derivatives containing thioxobenzo[g]pteridine ring systems were obtained starting from ethyl 3-amino-1,4-dihydroquinoxaline-2-carboxylate 1. These newly synthesized compounds were docked within the active site of cyclooxygenase-2 (COX-2). The results of this docking study revealed that the new compounds might exhibit good anti-inflammatory activity. The structure of new compounds was demonstrated by elemental analysis, IR, 1H NMR spectra and mass spectra