1H and 13C \NMR\ spectra of condensed benzimidazole and imidazobenzodiazepines

International audienceBenzimidazoles are heterocyclic compounds that have awakened great interest during the last few years because of their proven biological activity as antiviral, antimicrobial, and antitumoral agents. For this reason, the development of a systematic \NMR\ study of condensed benzimidazole compounds constitutes a significant tool in understanding the molecular dynamics and the structural parameters that govern their behavior. The 1H and 13C \NMR\ spectra of new imidazobenzodiazepines were investigated. Based on the study of \NMR\ chemical shifts, we discuss the environmental effect of the nucleus 13C. The correlation 1H-13C proved to be a useful method for distinguishing the assignment of carbon

Condensation of 7-nitroindole-2-carbohydrazide derivatives with ethyl acetoacetate

International audiencePyrazolylindolyl ketone derivatives were obtained by cyclization of the condensation products 7-nitroindole-2-carbohydrazide derivatives with ethyl acetoacetate. We have shown careful examination of spectroscopic data and the open-chain intermediate isolation as well as the identification of the formed compound structure

Improved method of S-alkylation of 2-mercaptobenzimidazole derivatives with trialkylphosphite

International audienceA new method of S-alkylation of 2-mercaptobenzimidazole derivatives has been developed by the condensation of these heterocycles with trialkylphosphite in the presence of phosphorus oxychloride giving the corresponding 2-S-alkylbenzimidazoles. The structure of the obtained products has been established by spectroscopic data

Novel and improved method for the synthesis of 2-mercaptobenzimidazole derivatives

International audience2-mercaptobenzimidazole derivatives were synthesized by reaction of o-phenylenediamines with N-aminorhodanine. This reaction represent a new synthesis of 2-mercaptobenzazole. The structure of the obtained products was established by spectroscopic data. © 2016, Oriental Scientific Publishing Company. All rights reserved

Water-soluble pegylated quantum dots: from a composite hexagonal phase to isolated micelles

International audienceWe present a simple method based on the dispersion of fluorescent quantum dots (QD) into a liquid crystal phase that provides either nanostructured material or isolated QD micelles depending on water concentration. The liquid-crystal phase was obtained by using a gallate amphiphile with a poly(ethylene glycol) chain as the polar headgroup, named I. The hydration of QD/I mixtures resulted in the formation of a composite hexagonal phase identified by small-angle X-ray scattering and by polarized light and fluorescence optical microscopy, showing a homogeneous distribution of fluorescence within hexagonal phase. This composite mesophase can be converted into isolated QD-I micelles by dilution in water. The fluorescent QD-I micelles, purified by size exclusion chromatography, are well monodisperse with a hydrodynamic diameter of 20-30 nm. Moreover, these QD do not show any nonspecific adsorption on lipid or cell membranes. By simply adjusting the water content, the PEG gallate amphiphile I provides a simple method to prepare a self-organized composite phase or pegylated water soluble QD micelles for biological applications

Condensation of lactones with primary diamines

International audienceThe condensation of dehydroacetic acid and 4-hydroxy-6-methylpyran-2-one with primary diamine derivatives such as hydrazine, 1,2- diaminoethane and 1,6-diaminohexane yielded bispyrone and bispyridone derivatives has been reported. The condensation of 4-hydroxy- 6-methylpyran-2-one with hydrazine in acetonitrile generated another bispyrazole product but in n-butanol, this reaction afforded the bispyridones. The structures of the synthesized bispyrazoles were examined by spectroscopy and X-ray diffraction analysis, while those of bispyridones were established by spectroscopy data (NMR, mass). Some new complexes were also synthesized in order to show the behaviour of ligands with suitable crystals for X-ray analysis. © 2021 Chemical Publishing Co.. All rights reserved