| 摘要 |
NEW MATERIAL:A dimethoxybenzalhydantoin derivative shown by formula I (X is H or -CH2-CH2CO2R; R is 1-18C alkyl, cyclohexyl or trimethylcyclohexyl. EXAMPLE:4-( 3,4-Dimethoxyhenyl )methylene-2,5-dioxo-1,3-imidazolidinedipropio- nic acid dimetyl ester. USE:An ultraviolet light absorber having ultraviolet light absorbing ability, safety, solubility in solvent and resin and stability, effective for preventing sunburn, stain, freckle, etc. PREPARATION:Dimethoxybenzaldehyde shown by formula II is condensed with hydantoin shown by formula III in the presence of a basic catalyst to give dimethoxybenzalhydantoin shown by formula IV, to which an acrylic acid ester is subjected to Michael addition to give a compound shown by formula I. |
