Synthesis and ocular effects of imidazole nitrolic acids

Contemporary Progress in the Synthetic Strategies of Imidazole and its Biological Activities

Heterocyclic compounds are pervasive in many areas of life and one of the heterocycles, imidazole is a unique heterocyclic five-membered aromatic compound having two sp2 hybridized nitrogen atoms. Its integral name is 1, 3 diazole and previously, it was known as glyoxalin. This moiety has achieved a considerable place among scientists in recent years by reason of its divergent synthetic strategies and uncommon biological and pharmacological activities, for example, anti-convulsant, anti-microbial, anti-cancer, anti-inflammatory, anti-tumor, anti-viral, anti-ulcer, analgesic, etc. Due to distinct therapeutic actions, it is still an engrossed area of research. Researchers currently are inventing new greener methods to synthesize its derivatives and to improve its pharmacological activities. The purpose of this review is to study the literature that can help researchers to explore this area, its prevailing program for synthesis in environmentally friendly conditions and biological profile throughout past decades.

A simple and convenient method for the synthesis of 1,3,5-triazine-nitrolic acids. The first X-ray investigation of Z-isomeric nitrolic acid

A simple and convenient method for the preparation of 2,4-disubstituted 1,3,5-triazine-nitrolic acids has been developed. The first example of nitrolic acid with Z-configuration was revealed by X-ray crystallographic analysis.

Synthesis of oxime-based CO-releasing molecules, CORMs and their immobilization on maghemite nanoparticles for magnetic-field induced CO release

Labile and intensely colored CORMs are stabilized in alginate–dextran composites.

Copper-catalyzed oxidative coupling reaction of α,β-unsaturated aldehydes with amidines: synthesis of 1,2,4-trisubstituted-1H-imidazole-5-carbaldehydes

A convenient synthesis of 1,2,4-trisubstituted-1H-imidazole-5-carbaldehydes was developed, which features high atom economy, cheap catalysts and mild conditions.

Ni(ii)–salt catalyzed activation of primary amine-sp3Cα–H and cyclization with 1,2-diketone to tetrasubstituted imidazoles

NiCl₂·6H₂O and Ni(OAc)₂·4H₂O were found as efficient catalysts for C–H activation of benzyl and aliphatic amines for an unprecedented multi C–N bond forming cyclization with 1,2-diketones under refluxing toluene to furnish highly substituted and polycyclic imidazoles.

Stability and decarbonylation of 1,3-dialkyl-2-formylimidazolium perchlorate in solution

The stability of 1,3-dialkyl-2-formylimidazolium perchlorate 1 in solution was studied in detail and found to be related to its structure and the solvent character and temperature. 1 was stable in common solvents at room temperature and unstable in protic solvents under reflux. In protic solvents, such as H2O, MeOH, EtOH, and AcOH, 1 decarbonylated into 1,3-dialkylimidazole perchlorates 2, which was confirmed by 1H NMR, 13C NMR, HRMS, and X-ray spectroscopy. The decarbonylation of 1 was proposed to occur via its hemiacetal formed by the addition of solvents based on the tracking NMR spectra of 1 in deuterated reagents.

Ruthenium imidazole oxime carbonyls and their activities as CO-releasing molecules

Six ruthenium carbonyl complexes with imidazole and alkoxy carbonyl ligands were prepared and found to act as carbon monoxide releasing molecules (CORMs).

Novel synthon for incorporating 1,3-dimethyl imidazolium group into molecular architecture

The synthesized 1,3-dimethylated imidazolium carbaldehydes serves as synthons for incorporating a permanently cationic imidazolium group into molecular framework. The utility of new synthon was demonstrated in a variety of reactions: Knoevenagel, Wittig, Schiff base formation, based mediated electrophilic substitution and oxidation, including synthesis of the natural product norzooanemonin.

Synthesis and ocular effects of imidazole nitrolic acid and amidoxime esters

Esters of 1-(H)-imidazole-5-nitrolic acid and 1-methyl-imidazole-5-carboxamide oxime were prepared to study the effect of esterification on the ocular effects of these compounds. Esterifications were performed with acid chloride. Acid chloride also reacts with the ring nitrogen of 1-(H)-imidazole-5-nitrolic acid, but the desired esters could be selectively prepared by adjustment of the reaction conditions. Esterification led to loss of the ocular effects exhibited by the parent compounds.

Electrospray ionization mass spectrometric studies of some imidazole amidoximes and nitrolic acids and their esters

The fragmentations of the [M+H]+ ions of imidazole amidoximes, and nitrolic acids and their esters, were studied by collision-induced dissociation experiments and by determining the accurate masses of the product ions on an electrospray ionization Fourier transform ion cyclotron resonance mass spectrometer. The fragmentation pathways of the amidoximes varied with the substituent in the imidazole ring at position 1N, allowing two regioisomers to be distinguished. Nitrolic acids decompose in solution to nitrile oxides, and the studied nitrolic acid behaved in the same way in the gas phase. The esters decompose similarly to their parent compounds.