R. K. P. Singh

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

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.

Anodic Synthesis of New Benzofuran Derivatives Using Active Methylene Group at Platinum Electrode

A facile and Eco-compatible synthesis of benzofuran derivatives (4a–4h) has been carried out at platinum electrode by electrochemical oxidation of catechol in the presence of active methylene groups. Electro- organic synthesis has been performed in an undivided cell at ambient conditions. The products of electrolysis have been purified and characterized by FTIR, 1H NMR and 13C NMR and mechanism was deduced by voltammetric studies.