| 摘要 |
NEW MATERIAL:4'-Lower alkoxy-2-alkoxycarbonyldibenzoylmethane of formula I (R1 is 1-18C straight or branched alkyl; R2 is lower alkyl). EXAMPLE:4'-Methoxy-2-methoxycarbonyldibenzoylmethane. USE:Useful as an ultraviolet-absorber for cosmetic such as skin cosmetic, hair cosmetic, etc. The compound of formula I is fat-soluble odorless crystal or oil having light yellow color, effective to absorb harmful UV-A region ultraviolet radiation and protecting the skin from the adverse effect of the radiation. It has high age-stability to light and heat and is soluble easily in a solvent for cosmetic. PREPARATION:The compound of formula I can be produced by reacting the compound of formula II with a halogenation reagent in an inert solvent and reacting the resultant compound of formula III with an alcohol in the presence of a base. |
