紫外线吸收剂丁基甲氧基二苯甲酰甲烷(巴松1789)的合成

Synthesis of UV-absorbent butyl methoxy-dibenzoylmethane (Parsol 1789)

以醋酸酐、苯甲醚和对叔丁基苯甲酸甲酯为原料,先经过傅克酰基化反应合成对甲氧基苯乙酮,再经过克莱森缩合反应合成丁基甲氧基二苯甲酰甲烷(Parsol 1789).傅克酰基化反应以磷钨酸为催化剂,n(苯甲醚)∶n(乙酸酐)=1∶1.5,反应时间4 h,反应温度110℃,收率为92%.克莱森缩合反应以氨基钠为催化剂,二甲苯为溶剂,n(对甲氧基苯乙酮)∶n(对叔丁基苯甲酸甲酯)=1∶1.4,反应6小时,反应温度100℃,收率68%.对中间体及产物结构经1HNMR分析进行了表征.

Butyl methoxy-dibenzoyl-methane（parsol1789） was synthesized from acetic anhydride,methylphenoxide and methyl tert-butyl-benzene,via a Friedel-Crafts Acylation of methoxyacetophenone and subsequent Claisen condensation.Acylation gave 92% yield by n（Anisole）∶n（acetic anhydride）=1∶1.5 at 110 ℃ with phosphotungstic acid as catalyst reactiomn for 4h.and Condensation gave 68% yield by n（p-methoxy acetophenone）∶n（Methyl tert-butyl benzene）=1∶1.4 at 100 ℃ with Sodium amide acid as catalyst and xylene as the solvent reaction 6 h.The structures of the intermediates and products were characterized by 1HNMR analysis.