A fast and highly efficient one-pot synthesis of novel isoxazolyl pyrido[2,3-<i>b</i>][1,4]oxazin-2(3<i>H</i>)-ones via Smiles rearrangement using task-specific ionic liquid [HMIm]BF₄as green solvent

Abstract

A facile and convenient procedure for the synthesis of isoxazolyl pyrido[2,3-b][1,4]oxazin-2(3H)-ones via Smiles rearrangement from isoxazole amine, chloroacetyl chloride and 2-chloro-3-hydroxypyridine using [HMIm]BF4 as task-specific ionic liquid has been described. The protocol proves to be efficient and environmentally benign in terms of high yields, eco-friendly solvent, ease of recovery, and reusability of reaction medium.