Abstract Treatment of arylglyoxal monohydrates with tetrasulfur tetranitride in p-dioxane at reflux afforded 2-aroyl-5-arylimidizoles and 2-aroyl-5-aryloxazoles in 10 to 31% and 17 to 32% yields, respectively. With non-hydrate of arylglyoxals, yields of the latter increase
