REACTION BETWEEN THE MASKED 1,3-DIPOLE OF ONE OXAZOLINONE AND 1-NITROSO-2-NAPHTHOL - NEW SYNTHESIS OF NAPHTHOXAZOLES

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-nitros o-2-naphthol. The reaction yields two naphthoxazoles: 2-phenylnaphtho[ 1,2-d]oxazole, 2-p-methoxyphenylnaphtho[1,2-d]oxazole and a naphthoxaz inone: 2-phenyl-3H-naphtho[2,1-b]-1, ,4-oxazin-3-one in approximately equal yields. Mechanisms for the formation of these compounds are prop osed. The reaction provides a new synthesis of naphthoxazoles.