Method for the preparation of symmetrical monoacetals of aromatic 1,2-diketones starting from the corresponding alphahydroxyketones
申请人:FRATELLI LAMBERTI S.p.A.
公开号:EP0085031A2
公开(公告)日:1983-08-03
The invention relates to a process for the production of symmetrical monoacetals of aromatic 1,2-diketones starting from the corresponding alphahydroxyketones and to their use as photoinitiators of polymerisation by ultraviolet radiations.
According to the process of the invention, protection of the carbonyl group is not operated, and the aromatic alphahydroxyketones react, in the first step of the reaction, with an halogenating agent in presence of N-substituted aliphatic amide or an aliphatic alcohol from 1 to 5 atoms and, in the second step, with an alkaline metal alcoholate or an alcohol. If the carbonylic group is protected, the alphahydroxyketones are first converted into acetals or hydrazones and then into the products of the invention by means of oxidation or acetalisation.
本发明涉及从相应的α-羟基酮开始生产芳香族 1,2-二酮的对称单乙醛的工艺,以及将其用作紫外线聚合的光引发剂。
根据本发明的工艺,不对羰基进行保护,在反应的第一步,芳香族α-羟基酮在 1 至 5 个原子的 N-取代脂肪族酰胺或脂肪族醇存在下与卤化剂反应,在第二步,与碱金属醇酸酯或醇反应。如果羰基受到保护,α-羟基酮首先转化为缩醛或酰肼,然后通过氧化或缩醛化反应转化为本发明的产品。