Abstract
Reaction of 4-alkoxyquinazolines (II) with perphthalic acid afforded, besides the objective 4-alkoxyquinazoline 1-oxides (III), 2-hydroxy-4-alkoxyquinazoline 1-oxides (IV) as a by-product, formed by oxidation of 2-position. (III) was hydrolyzed to 4-hydroxyquinazoline 1-oxide (V), methylated, and catalytically reduced to 3-methyl-4-quinazolone (VII), whose identification by admixture with an authentic specimen proved the original compounds to be the 1-oxide. The structure of (IV) was also proved by its methylation followed by catalytic reduction to form 4-alkoxy-2-quinazolone (IX).
