Abstract

The azomethin ylide of the 2-p-methoxyphenyl-4-phenyl-2-oxazolin-5-one underwent 1,3-dipolar cycloaddition to both tautomers of the 1-nitroso-2-naphthol. The reaction yields two naphthoxazoles: 2-phenylnaphtho[1,2-d]oxazole, 2-p-methoxyphenylnaphtho[1,2-d]oxazole and a naphthoxazinone: 2-phenyl-3H-naphtho[2,1-b]-1,4-oxazin-3-one in approximately equal yields. Mechanisms for the formation of these compounds are proposed. The reaction provides a new synthesis of naphthoxazoles.