Microwave-Assisted Rapid and Straightforward Synthesis of Novel 6-(Aroxymethyl)-2-aryl-6,7-dihydropyrazolo[5,1-c][1,4]oxazin-4-one Derivatives.

A series of novel 6-(aroxymethyl)-2-aryl-6,7-dihydropyrazolo[5,1-c][1,4] oxazin-4-one derivatives was synthesized from ethyl 3-aryl-1H-pyrazole-5-carboxylate and 2-aryloxymethylepoxide by a microwave-assisted, one-step method in good yields. The microwave-assisted reaction of ethyl 3-aryl-1H-pyrazole-5-carboxylate and 2-aryloxymethylepoxide proceeds with higher regioselectivity and is more economical and environmentally friendly in contrast to the normal intramolecular esterification route. A tandem mechanism of the reaction was proposed. [ABSTRACT FROM AUTHOR]