NOVEL ROUTES TO 1-ARYL-1,4-DIHYDRO-3(2H)-ISOQUINOLINONES AND 2-SUBSTITUTED OR 2,3-DISUBSTITUTED BENZOFURANS BY INTRAMOLECULAR CYCLIZATIONS

N-(alpha-Benzotriazolylalkyl)arylacetamides, readily available from an arylacetamide, an aldehyde and benzotriazole, undergo intramolecular cyclization under acidic conditions to give 1-aryl-1,4-dihydro-3(2H)-isoquinolinones in good to excellent yields. Similarly, 2-(benzotriazol-1-yl)-2-(o-hydroxyphenyl)ethanols, obtained by lithiation of 2-(benzotriazol-1-ylmethyl)phenols followed by quenching with aldehydes or ketones, eliminate a molecule of water and a molecule of benzotriazole yielding 2-substituted and 2,3-disubstituted benzofurans.