Photo- and thermochromic spiropyrans. 21. 8"-Formyl-3,6"-dimethyl-4-oxospiro(3,4-dihydro-2H-1,3-benzoxazine-2,2"-[2H ]chromene) possessing photochromic properties in the solid phase

Spiropyran of the chromene series, viz., 8"-formyl-3,6"-dimethyl-4-oxospiro(3,4-dihydro-2H-1,3-benzoxazine-2,2"-[2H]chromene), was synthesized. In the solid phase, this compound exhibits photochromic properties. These properties were examined and the crystal structure of the compound was established by X-ray diffraction analysis. The compound is a convenient starting reagent for the synthesis of new spiropyrans containing functional groups at position 8".