Kojic acid derivatives and preparation method thereof and whitening cosmetic composition containing the kojic acid derivatives

摘要

PURPOSE: Kojic acid derivatives, a preparation method thereof, and a whitening cosmetic composition containing the same are provided, thereby inhibiting melanine formation, and improving stability of kojic acid derivatives, so that the kojic acid derivatives can be stably applied to the cosmetic composition. CONSTITUTION: The kojic acid derivatives represented by formula (I) are provided, wherein R is CH2-CH2 , CH=CH, CH2-CH2-CH2 , CH2-CH-(CH3)-CH2 , CH2-CH(CH3)2-CH2 , C6H4-1,4-, C6H4-1,3-, CH=CHCH=CH, C5H3N-2,5- or C5H3N-3,5-. The method for preparing the kojic acid derivatives of formula (I) comprises the steps of: (A) reacting dicarboxylic acid with chloride to prepare acid chloride of dicarboxylic acid; and (B) reacting the acid chloride of dicarboxylic acid with two molecules of kojic acid to form an ester bond between them, wherein chloride is selected from thionyl chloride, oxalyl chloride, phosphorous trichloride and phosphorous oxychloride. The whitening cosmetic composition contains 0.01 to 20 wt.% of kojic acid derivatives.