| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject compound that is useful as an ultraviolet absorber for polymers and cosmetics by allowing a polyhydroxybenzophenone with an alkyl halide in the presence of an alkali to effect partial alkylation and facilitate the recovery of the solvents and the separation of inorganic salts. SOLUTION: A polyhydroxybenzophenone of formula I (R, R1 and R2 are each H, alkyl, hydroxy) is allowed to react with an alkyl halide in the presence of a quaternary ammonium salt of formula II (R6 -R9 are each an alkyl; X is Cl, Br), a tertiary amine as tributylamine, triethylamine, and a halogenated alkali metal as potassium iodide or potassium bromide in a hydrocarbon solvent as toluene, xylene or heptane in 0.7-3-fold volume of the reactants to effect partial alkylation thereby forming the objective benzophenone of formula III (R3 is an alkyl; R4 and R5 are each H, an alkyl, a halogen and the like). |
