New Corrosion inhibition of mild steel by 7-bromopyrido[2,3-b]pyrazine-2,3(1H, 4H)-dithiol in 1M hydrochloric acid solution

The corrosion inhibition performance of synthesized inhibitor 7-bromopyrido[2,3-b]pyrazine-2,3(1H,4H)-dithiol (M2) was investigated on mild steel corrosion in 1 HCl using gravimetric and electrochemical measurements. The studied inhibitor, M2showed the maximum inhibition efficiency (E) of 91% at a concentration as low as 10-3M. The potentiodynamic polarization studies showed that the studied inhibitor (M2) act as mixed inhibitor. The results of EIS studies showed that in the presence of inhibitor M2, transfert charge resistance increased and Cdl decreased due adsorption of inhibitor at the mild steel surface. The adsorption of inhibitor molecules on mild steel surface obeys the Langmuir adsorption isotherm. The results of the theoretical investigation and experimental studies well complimented each other

SYNTHESE DE NOUVEAUX DERIVES DE LA 5-BROMO-1H-INDOLE-2,3-DIONE A VISEE THERAPEUTIQUE.

In this work we describe the synthesis of a new 5-bromo-isatin derivatives using alkylation reactions under phase transfer catalysis (PTC) conditions. The structures of the various products obtained were determined by 1H NMR, 13C NMR spectroscopy and mass spectrometry.Nous décrivons, dans ce travail, une méthode simple et efficace pour préparer de nouveaux dérivés de la 5-bromo-isatine en réalisant des réactions d’alkylation dans les conditions de la catalyse par transfert de phase (CTP). Les structures des différents produits obtenus ont été déterminées par voie spectroscopique (RMN 1H, RMN 13C et spectrométrie de masse)

Synthesis and reactivity of new heterocyclic systems derived from 5-chloro-1H-indole-2,3-dione

In this article, we described the synthesis of various derivatives of 5-Chloroisatin by the action of halogenated mono channels, benzyl chloride and methyl iodide under the conditions of phase transfer catalysis (PTC), which are widely used as a starting material for the synthesis of heterocyclic compounds and as substrates for the synthesis of drugs. In order to multiply the family heterocyclic compound from 5-Chloro-1H-indole-2,3-dione using the N-alkylation reaction which is answered in the field of organic chemistry and on which several studies were performed. The various products were determined by 1H NMR, and 13C NMR spectroscopy with good yield

SYNTHESE DE 2-t-BUTOXY-FURANES SUBSTITUES EN POSITION 5

Nous décrivons dans cet article la synthèse de nouveaux 2-tert-butoxyfuranes fonctionnalisés en position α par les groupements : époxyde 3, nitrile 4, hydrazide 8a, oxamide 6, 8b. La réaction conduit aux composés attendus avec des rendements satisfaisants. Ces dérives pourraient présenter des propriétés pharmacologiques potentielles.Fonctionalized 2-tert-butoxyfurane derivatives containing the following group: epoxide 3, cyano 4, hydrazide 8a, oxamide 6, 8b at the α - position of the oxygen atom are synthesized in good yield and are potentially active drug derivatives

ELECTROCHEMICAL REDUCTION OF CATIONIC: (η 5 -CYCLOPENTADIENYL) (η 6 -HALOGENOARENE) IRONE(II) COMPOUNDS

The reductive deshalogenation of cationic compounds (η 5 -C5H5)Fe+ (η 6 - halogenoarene) was investigated by cyclic voltammetry in organic solvents. In all cases, whatever the solvent or the substrate, the first reduction is a one-electron process leading to the corresponding neutral species (η 5 -C5H5)Fe(η 6 -halogenoarene). In coordinating solvents (CH3CN, DMF) these species are involved in a competition between decomposition and halide elimination. In CH2Cl2 or acetone the expected halide elimination of Cl- or Br- affords the deshalogenated compounds (η 5 -C5H5) Fe+ (η 6 -arene) after abstraction of hydrogen atom of the solvent by the intermediates (η 5 -C5H5) Fe+ (aryl radical). It is suggested that these intermediates are involved in decoordination occurring during the electrochemical reduction. For complexed monochloarenes, the yield of (η 5 -C5H5)Fe+ (η 6 -arene) increases with the electrodonating effect of substituent. The observed competition between reductive deshalogenation and decoordination throws light on the deshalogenation occurring during the preparation of the substrates (η 5 -C5H5)Fe+ (η 6 -halogenoarene). Key words: aromatic halogenated compounds, electrochemistry, reduction, cyclic voltammetr

Study of the inhibition of corrosion of mild steel in a 1M HCl solution by a new quaternary ammonium surfactant

The anticorrosive effect of surfactant, 12-(2,3-dioxoindolin-1-yl)-N,N,N-trimethyldodecanammonium bromide 3 on the corrosion of mild steel in 1M hydrochloric acid was assessed by gravimetric and electrochemical techniques (potentiodynamic polarization and electrochemical impedance spectroscopy). The results have shown that our synthesized surfactant is an excellent corrosion inhibitor for mild steel in 1 M HCl. Inhibitory efficacy of up to 95.9% was exhibited by surfactant 3 at a concentration of 1 mM after 6 h immersion at 298K. Based on the polarization curves, it is clear that the surfactant 3 can be considered as a mixed inhibitor with a predominantly anodic character. The inhibitory effectiveness increases with increasing concentration but decreases with increasing temperature. It was found that the adsorption of the inhibitor on the surface of the mild steel in 1M HCl followed the Langmuir adsorption isotherm. In this context, the main kinetic and thermodynamic parameters were determined and discussed

SYNTHESIS OF NEW 5-BROMO-1H-INDOLE-2,3-DIONE DERIVATIVES BY 1,3-DIPOLAR CYCLOADDITION

To contribute to the development of the chemistry of 5-bromo-isatin, we have synthesized new heterocyclic systems, using alkylation reactions under conditions of phase transfer catalysis to be then subjected to cycloaddition reactions dipolar involving 1,3-dipoles. The structures of the various products obtained were determined by 1H NMR, 13C NMR spectroscopy

1-[2-(2-OXO-OXAZOLIDINE-3-YL)ETHYL]-1,5- BENZODIAZEPINE-2,4-DIONE

Une nouvelle voie de synthèse de systèmes hétérocycliques possédant le motif 1,5-benzodiazepine-2,4-dione a été décrite. La réaction mise au point repose sur des conditions de la catalyse par transfert de phase solide-liquide. Les structures proposées sont confirmées par RMN, IR, spectrométrie de masse et une étude cristallographique aux rayons-X pour le dérivé 1.In this article, we describe a novel route to heterocyclic systems derived from 1,5- benzodiazepine-2,4-dione. The reactions were performed in heterogeneous media using phase transfer conditions. NMR, IR, mass spectroscopy and X-Ray crystallographic studies of compound 1 were carried out to confirm the suggested structure

ETUDE DES VIBRATIONS MOLECULAIRES DE LA 1,5- BENZODIAZEPINE-2,4-DIONE ET DE SES DERIVES

L’étude des vibrations moléculaires des benzodiazépines 1-6 a été réalisée. Les attributions expérimentales des vibrations moléculaires de ces composés ont été confirmées ou complétées par le calcul des modes normaux de leurs vibrations.The study of molecular vibrations of benzodiazepines 1-6 was done. The experimental attributions of the molecular vibrations of these compounds have been confirmed or completed by the computation of the normal modes of their vibrations

A novel route to 1,4-dihydroquinoxaline for biological and electrochemical properties

In this paper we describe the synthesis of new quinoxalines which can present a potential pharmacological properties The 6-methyl-1,4-dihydroquinoxaline-2,3-dione 3 was synthesized by the condensation of 4-methyl-o-phenylenediamine 1 with oxalic acid 2 under reflux in hydrochloric acid solution.Compound3 was exposed to alkylation reactions under the conditions of phase transfer catalysis using monohalogenated agents leading to alkylated products 3a-3f. Structures of the obtained products were confirmed by spectroscopic measurements