| abstract |
(2) is bonded to the carbon atom at the 6-position and / or the 7-position of the indeno (2,1-f) naphtho (1,2- R 3 and R 4 each independently represent an alkyl group, a haloalkyl group, a cycloalkyl group, an alkoxy group, an amino group, a reduced nitrogen atom, and each of R 3 and R 4 represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring, A halogen atom, an aryloxy group, or an aryl group, and a is an integer of 0 to 4), and is excellent in photochromic characteristics, and has a high temperature The present invention provides a chromene compound excellent in stability under a low temperature environment. |