| 摘要 |
PROBLEM TO BE SOLVED: To obtain a new compound useful as a photochromic material by introducing a cyano group as an electron attractive group to a specific site. SOLUTION: This compound is expressed by formula I (R is H or a >=1C alkyl), e.g. a dimer of 2,3-diphenyl-6,6-dicyanopentafulvene. The compound is obtained by subjecting a dehydrated acetone benzyl derivative of formula II to condensation reaction with malononitrile in benzene solvent in the presence of acetic acid, sodium acetate or piperidine as a catalyst to obtain a compound of formula III and subjecting the resultant compound to dehydration reaction in an acetic acid solvent in the presence of sulfuric acid as a catalyst. |
