Experimental study of electromechanical measurement, surface analysis and corrosion inhibition of mild steel in 1M HCL by Schiff’s bases (SBs)

Potentiodynamic polarization measurements indicate that SBs acts as mixed type corrosion inhibitors. the morphology of the mild steel surface is investigated by scanning electron microscopy (SEM) and the surface composition was evaluated using energy-dispersive X-ray Spectroscopy (EDX) to show the presence of SBs on the mild steel surface in 1M HCL. The present study, three Schiff’s bases (SBs) namely 2 (2-hydroxybenzylideneamino) heptanedioic acids, 2 (4-dimethylamino benzlideamino) heptanedioic acids and 2 (4hydroxy-3-methoxybenzylideneamino) heptanedioic acids were synthesized. Using weight loss, potentiodynamic polarization and electromechanical impedance spectroscopy (EIS) techniques for corrosion inhibition properties on mild steel in 1M HCL has been investigated. The adsorption of SBs on the mild steel surface contains Langmuir adsorption isotherm. Here kinetic and thermodynamic parameters also determined to describe the mechanism of adsorption in relevance. The main object of this presentation is experimental study of the inhibiting action of synthesized Schiff’s bases of aldehydes containing nitrogen, oxygen and aromatic rings and Glutamic acid.

Antibacterial and phytotoxic activity of the Schiff’s bases of 5-phenyl-4-amino-3-mercapto-4H-1,2,4-triazole with the donor substituents in the 4th position on heterosystem

Background. Triazoles and Schiff’s bases have a high biological activity. For the practical use of the derivatives, their low toxicity is important. The purpose of this work was to investigate the antibacterial and phytotoxic properties of Schiff’s bases of 5-phenyl-4-amino-3-mercapto-4H-1,2,4-triazole with donor substituents in the 4th position of heterosystem. Materials and methods. In the study of antibacterial activity of the derivatives, corrosion-active 4-day association cultures of ammonifying and sulfate-reducing bacteria were used as a test culture of microorganisms. Sensitivity of bacteria to derivatives was determined by diffusion method in agar using sterile paper disks according to the standard method. In the investigation of phytotoxic activity of the derivatives, Lepidium sativum of the “Ajour” cultivar was used as a test plant. Seed germination and biometric indices (length, weight of the aboveground part and roots) of 5-day sprouts were determined, the phytotoxic effect of the derivatives was calculated. Experimental data were processed using methods of mathematical statistics. Results. The introduction of substituents does not provide for an increase in antibacterial properties of the studied compounds in relation to some corrosion active ammonifying and sulfate-reducing bacteria. Low activity was observed regarding the association culture of ammonifying bacteria to the compound without substituents in the phenyl fragment and the compound with fluor as a substituent in the phenyl fragment at a concentration of 2.0%. Derivatives with the methoxyl substituent in the phenyl fragment and with the hydroxyl substituent in the phenyl fragment did not show any antibacterial activity against the association culture of ammonifying bacteria isolated from ferrosphere in meat-peptone broth. Antibacterial action against the association of sulfate-reducing bacteria Desulfovibrio orizae with organic acid-producing bacteria Anaerotignum propionicum for derivatives were not detected. Phytotoxic properties were observed for the compound with the hydroxyl substituent that influenced the processes of growth in the test plant. Conclusion. The introduction of electron-donor substituents into the basic structure did not provide for an increase in antibacterial properties against corrosive bacteria. Phytotoxic properties were observed for the compound with the hydroxyl substituent in the phenyl fragment, which influenced the L. sativum growth processes by inhibiting growth of the above-ground part and roots. Other compounds either did not show any action, or demonstrated a weak stimulating effect on the growth and development of the test plant.

Design, Synthesis of a Novel Banana-Shaped Compounds via Esterification

Schiff's Bases were synthesized from the reaction of p-amino benzoic acid and alkoxybenzaldehyde in absolute ethanol and reacted with (E)-3-((4-hydroxybenzylidene) amino) phenol used DCC (N,N'-Dicyclocarbodiimide) and DAMP (4-(Dimethylamino) pyridine ) to 3-(((E)-4-((4-(((E)-4 alkoxy benzylidene) amino) benzoyl) oxy) benzylidene) amino) phenyl4- (E)- 4-alkoxy benzyli dene ) amino) benzoate. The structures of the products were confirmed by their melting points, FT-IR, 1HNMR spectra.

Synthesis of Schiff’s Bases of 1,2,4-Triazole Derivatives under Microwave Irradiation Technique and Evaluation of Their Anti-diabetic Activity

Background: Schiff bases play key role for the generation of a large number of biologically active compounds via cycloaddition, replacement and ring closure reactions. Objective: The objective of this study is to optimize the purity and yield of product, reaction time, eco-friendly reaction by the help of microwave assisted organic synthesis. Methods: New series of Schiff’s bases of triazole derivatives were achieved via multicomponent reactions. The starting material benzohydrazide 1 was obtained by esterification of bezoyl chloride with methanol in presence of concentrated sulphuric acid followed by the reaction with hydrazine hydrate. Benzohydrazide was allowed to react with carbon disulphide in ethanolic potassium hydroxide solution to yield potassium dithiocarbazinate 2 which undergoes cyclization by reacting with hydrazine hydrate to afford 4-[amino]-5-phenyl-4H-1,2,4-triazole-3-thiol (3). Further, various Schiff’s bases 4a-f were obtained by reacting 1,2,4-triazole-3-thiol with different substituted benzaldehydes under microwave irradiations as a green and eco-friendly energy source. Results: The structures of the newly synthesized compounds were elucidated in accordance with their spectral data and elemental analysis. Conclusion : The obtained compounds exhibited significant in-vivo anti-diabetic activity as compared to the standard drug Metformin. The anti-diabetic effect was investigated by using Alloxan-induced diabetic model.

SYNTHESIS OF A NOVEL SERIES OF SCHIFF’S BASES FROM PABA AND PHENYL HYDRAZINE AND EVALUATION OF THEIR ANTIOXIDANT ACTIVITY

Over the past decade, the synthesis of Schiff’s bases has become one of the main areas of interest in synthetic chemistry. These compounds have gained much attention, owing to their potential role as anti-inflammatory, anthelmintic, analgesic, antibacterial and antifungal agents. Thus, in view of the significance and diverse therapeutic activities of Schiff’s bases we have aimed at a simple and efficient procedure for their synthesis by the reaction of various aldehydes with PABA and phenyl hydrazine and also evaluation of their antibacterial activities. We have been successful in synthesizing various Schiff’s bases and also these compounds have been proved to have effective anti-oxidant activity. KEYWORDS: Schiff’s bases, PABA, Phenyl hydrazine, Aldehydes, Dioxan, Hydrogen peroxide, scavenging activity

Synthesis, characterization and anti-bacterial activity of novel schiff bases of pyridin-3 yl-carbohydrazide derivatives

Heterocyclic compounds are cyclic compounds containing carbon and other heteroatoms. The most common heteroatoms are oxygen, nitrogen, and Sulphur. A heterocyclic compound is a cyclic compound that has atoms at least two different elements as members of its ring. A Schiff base (azomethine) is named after its inventor, Hugo Schiff and it is a functional group that contains a carbon-nitrogen double bond with the nitrogen atom connected to an aryl or alkyl group but not hydrogen. Schiff bases of Pyridin-3 yl-carbohydrazide derivatives from ethyl nicotinate and different aromatic aldehydes. Schiff’s bases are aromatic substituted imine compounds. These compounds are very important in the medicinal and pharmaceutical fields because of their wide spectrum of biological activity. Schiff’s bases show antibacterial activity, antifungal activity, and also antitumor activity. Aromatic aldehydes were refluxed with ethyl nicotinate using ethanol as a solvent to form Schiff's bases. All chemicals are taken in equimolar concentrations. The synthesized compounds were characterized by melting point, solubility, percentage yield, TLC, and IR spectral analysis. All derivatives are evaluated for anti-bacterial activity by the cup plate method. The antibacterial activity of test compounds was compared against standard Streptomycin. The 5 synthesized compounds show moderate antimicrobial activity. The experimental work summarizes the synthesis and in-vitro antibacterial activity of Schiff base derivatives.

A novel acyl hydrazone schiff’s bases of benzimidazole-2-thiol

A series of novel acyl hydrazone derivatives of benzimidazole-2-thiol were synthesized. The acylhydrazide was condensed with a series of aromatic substituted aldehydes to yield the tetra decylhydrazone Schiff”s bases of benzimidazole-2-thiol. The acylhydrazide was taken in methanol in round bottom flask added 2-3 drops acetic acid and refluxed on hotplate the reaction mixture was monitored with TLC. After completion of reaction the product was precipitated in ice cool water, washed and dried. The synthesized compounds were screened for different biological activities such as antimicrobial, antihistamine, neutropic, analgesic, antiprotozoal, antimalarial, antiallergic, antioxidant, anticonvulsant, anti-tubercular and have shown a good results.