Investigation of the Synthesis of Benzoxazole via Aryne Reaction

Article abstract of DOI:10.1021/jo00329a022

The reaction of o- and m-halobenzamides under aryne-forming conditions yielded the corresponding o-hydroxyphenyl amidines instead of the expected benzoxazole derivatives.The amidines, however, were converted to the corresponding benzoxazole either by sublimation or acidic hydrolysis.Evidence is presented that benzoxazoles are initially formed in these reactions but are readily aminated to the corresponding hydroxyphenyl amidines under the highly basic reaction conditions used in these aryne-forming reactions.