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

Abstract

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.

Keywords:

• microwave assisted
• pyrazole derivatives
• synthesis

Acknowledgments

This study was supported by the Foundation of the Ministry of Education (104112) and the Natural Science Foundation of Shandong Province (Y2005B12).