The invention provides an
indene-fused 2H-naphtho-[2,1-b]
pyran photochromic compound and a preparation method thereof. The molecular formula of the compound is shown in a formula I, wherein R1 and R2are
hydrogen, straight-chain or branched-chain
alkyl groups containing 1-6 carbon atoms, straight-chain or branched-chain alkoxy groups containing 1-6 carbon atoms, straight-chain or branched-chain halogenated
alkyl groups or halogenated alkoxy groups, substituted by at least one
halogen atom, corresponding to the
alkyl groups and the alkoxy groups respectively, phenyl groups or substituted phenylgroups,
halogen, NH2 and <->NHR. The preparation method of the compound comprises the steps that 2-methoxycarbonylphenylboronic acid
pinacol ester and 4-
bromine-2-naphthol are subjected to a couplingreaction, a
Grignard reagent addition reaction and a cyclization reaction to obtain an intermediate 7,7-dialkyl-7H-benzo-[c]
fluorene-6-
phenol, and then the intermediate and 1,1-(diaryl)-2-allylene-1-ol generate I under the
acid catalysis. The synthesis of the photochromic compound I has the advantages that the steps are few, the
reaction conditions are mild, the operation is simple, and the reaction yield is high, a color body of the photochromic compound I is yellow or orange, and the photochromic compound I has the advantages of good
fatigue resistance and
high color ratio.