Apoorv Saraswat

Electrosynthesis and screening of novel 1,3,4-oxadiazoles as potent and selective antifungal agents

The electrochemical oxidation of aldehyde-N-aroylhydrazone has been studied in the presence of NaClO4 as supporting electrolyte in MeOH solution using cyclic voltammetry and controlled potential electrolysis. The results indicate that intramolecular cyclization of aldehyde-N-aroylhydrazone has been successfully performed at a platinum electrode in an undivided cell with good yields of the corresponding 1,3,4-oxadiazoles at ambient conditions. The reaction products were characterized by spectroscopic methods and a mechanism was deduced from voltammetry studies. The antifungal activity of the synthesized compounds was evaluated on Fusarium oxysporum, Alternaria solani, Candida albicans and Aspergillus niger. The results revealed that all the synthesized compounds have significant antifungal activity against the tested fungi. Among the synthesized derivatives 7b, 7d, 7g, 7h, 7i, 7j and 7r were found to be the most effective antifungal compounds.

Electrochemically initiated oxidative cyclization: a versatile route for the synthesis of 5-substituted 2-amino-1,3,4-oxadiazoles

A rapid, improved, and environmentally benign synthesis of 5-substituted 2-amino-1,3,4-oxadiazoles by one-pot electrocyclization of acylthiosemicarbazones is reported. Controlled potential electrolysis was performed at room temperature in acetonitrile as non-aqueous solvent and LiClO4 as supporting electrolyte. The reaction products were characterized by spectroscopic methods and a mechanism was deduced from voltammetric data. Better yields at room temperature, shortest reaction time, and easy work-up are attractive features of this green procedure.Graphical Abstract

Electrochemical oxidation of aldehyde- N -arylhydrazones into symmetrical-2,5-disubstituted-1,3,4-oxadiazoles

A convenient, efficient and one-pot synthesis of chemically and pharmaceutically interesting symmetrical-2,5-disubstituted-1,3,4-oxadiazoles is reported. The protocol involves anodic oxidation of aldehyde-N-arylhydrazones in anhyd. MeCN–LiClO4. Constant potential electrolysis carried out in an undivided cell and platinum electrodes leads to the formation of the corresponding oxadiazoles under ambient condition and the mechanism was deduced from voltammetry studies. The reaction proceeded smoothly with high atom economy.

Anodic Cyclization: A Protocol for the Green Synthesis of 2,5-Disubstituted 1,3,4-Oxadiazoles

An efficient and simple one-pot synthesis of chemically and pharmaceutically interesting 2,5-di-substituted 1,3,4-oxadiazoles is reported. The protocol involves anodic oxidation of N′-aroyl-hydrazones of aromatic aldehydes using LiClO4 as supporting electrolyte in MeCN solution under controlled potential at room temperature. The products were characterized by spectroscopic methods, and the mechanism was deduced from voltammetry studies. The mild reaction conditions, short reaction time, and excellent yields are notable advantages of the developed protocol.

Anodic fluorination of 4-methoxy-1-naphthol and 4-nitroanisole using Et3N · 5 HF in mixed nonaqueous solvent

Anodic fluorination of 4-methoxy-1-naphthol and 4-nitroanisole has been investigated in a mixed nonaqueous solvent using Et3N · 5 HF as supporting electrolyte as well as fluorine source. In order to avoid the formation of polymer on the anode, pulse electrolysis was carried out without exchanging the electrodes. The proposed procedure ensures excellent yield at room temperature, shortest reaction time, and easy work-up which provide additional advantages in the context of green chemistry. Experimental parameters of the reaction are discussed.

Electrochemical behaviour of aldehyde- N -arylhydrazones at platinum electrode and their characterization

A series of chemically and pharmaceutically interesting 2,5-disubstituted-1,3,4-oxadiazoles were efficiently synthesized from the anodic oxidation of aldehyde-N-arylhydrazones at platinum anode by using NaClO4 as supporting electrolyte in MeOH solution under controlled potential electrolysis at room temperature. The products were characterized by spectroscopic methods and a mechanism was deduced from voltammetry studies. The salient features of this protocol are mild reaction conditions, short reaction time, accelerated rate, high yield and simple work-up procedure.

Electrogenerated Base: A Green Protocol for Synthesis of Arylidene Malononitrile.

The simple one-pot electrochemical synthesis of the title compounds (III) is achieved in organic medium using a simple supporting electrolyte.