Green Synthesis of Quinoxaline and Substituted QuinoxalinesAuthor(s): S. S. Ubarhande, P. P. Devhate and B. N. Berad
One pot green synthesis for quinoxaline and substituted quinoxalines has been developed using environmental friendly technique of microwave assisted synthesis. The quinoxaline itself (3g) and numerous other substituted qunoxalines (3a-3f) have been synthesized by using the condensation reaction of o-phenylenediamine and glyoxal, ethylene glycol, oxalic acid, glycolic acid, chloroacetic acid, benzil and benzoin, respectively. These have been synthesized in microwave after irradiation for 60 seconds at 160 watts. The granular solids obtained were crystallized from ethanol, while quinoxaline itself was purified by distillation. All the quinoxalines, barring (3a) and (3f), all other have been converted into their monoacetyl and monobenzoyl derivatives by treating them with acetic anhydride and benzoyl chloride in 1 : 1 proportion, respectively. The structural determination of different quinoxalines and their derivatives were established on the basis of elemental analysis and spectral data including IR, PMR and Mass spectra.