PROCESS FOR PREPARING PHOTOCHROMIC NAPHTHOPYRAN DYES

摘要

PURPOSE: A novel method for economically manufacturing naphthopyran based photochromic dye of high yield and high purity is provided. CONSTITUTION: A method for manufacturing naphthopyran based photochromic dye of chemical formula 1 comprises: a step of reacting amino naphtholic acid with alkyl- or benzyl-chloroformate to obtain a compound of chemical formula 4; a step of substituting the compound of chemical formula 4 with amine compound to obtain a compound of chemical formula 2; a step of reacting halogen-substituted benzo phenone with nucleophilic compound under the presence of base and reacting with sodium acetylide to obtain a compound of chemical formula 3; and a step of reacting the compound of chemical formula 3 with a compound of chemical formula 2.