A new spiro[indoline–naphthaline]ox

A new spiro[indoline–naphthaline]oxazine derivative 1 has been successfully synthesized and characterized, and its crystal structure has been obtained by recrystallization from the mixture solvents at room temperature. The crystal structure indicated that benzene and naphthalene rings in molecule 1 are similarly perpendicular, and atoms N1, N2, N3 and O2 are approximately coplanar with the naphthalene ring plane. Short intermolecular distances in the packing diagram were also investigated. In solvents, the title compound 1 exhibited excellent photochromic properties. The new photochromic compound 1 with high fatigue resistance may be successfully used as sunglasses, optical switching, optical data storage, etc.