| abstract |
A novel spiro-oxazine compound of the formula (A): <IMAGE> (A) wherein R1, R2, R3, R4, R5, R6 and R7 independently represent hydrogen, (C1 or 2) alkyl, halogenated (C1 or 2) alkyl, (C1 or 2) alkoxy, halogen or nitro, R is unsubstituted or substituted phenyl or naphthyl, and n is 1 to 5. The spiro-oxazine compound is prepared by reacting a precursor of the spiro-oxazine compound of the formula (A), which has a substituent of the formula: -(CH2)n R in the nitrogen atom of the indoline nucleus, with an alpha -nitroso- beta -naphthol. The spiro-oxazine compound is valuable as a photochromic material and exhibits enhanced fatigue resistance in photocolorability. |