Pyridinium Bromide Perbromide (PyHBr3) Promoted One-Pot Synthesis of Quinoxaline and Aminothiazole Derivatives From Acetophenone.

A straightforward, metal-free synthesis of quinoxaline and aminothiazole derivatives from acetophenone is reported. The reaction was found to be promoted by pyridinium bromide perbromide, a little-explored brominating reagent. A wide variety of substituted quinoxaline and aminothiazole derivatives can be prepared in quantities ranging from milligrams to multi-grams. The use of inexpensive starting materials and reagents makes the method both cost-effective and accessible for large-scale synthesis. Good and consistent yield of the product, operational ease, and environmental benignity make the method more acceptable and applicable in organic synthesis.