An efficient synthesis of pyrazole derivatives by condensation of 1,3-diketone and hydrazines/hydrazides has been achieved in aqueous hydrotropic solution under catalyst-free conditions within a very short time. The present protocol is beneficial as it includes mild reaction conditions, shorter reaction times, use of universal solvent water, which avoids volatile organic solvents, high yields of products, and being environmentally friendly.
An efficient practical chemo-enzymatic protocol for the synthesis of pyrazoles in aqueous medium at ambient temperature
An expeditious oxidative cyclocondensation reaction of hydrazines/hydrazides with 1,3-dicarbonyl compound was efficiently developed in aqueous medium using Saccharomyces cerevisae (baker's yeast) as a whole cell biocatalyst at room temperature. The method has been assigned using green chemistry measures and found to give a range of N-substituted pyrazoles with moderate to excellent yields (70-92%). The reaction progress was monitored by gas chromatography. (C) 2015 Elsevier B.V. All rights reserved.