丹皮酚的选择性溴化反应

The selective bromination of paeonol (4-methoxy-2-hydroxyacetophenone) has been studied as function of solvents(methanol, ethanol, chloroform-ethyl acetate), reaction time, temperature and the mole ratio of reagents. The higher yield was obtained in polar solvents than in non-polar ones. The best solvent appeared methanol, and the mixtures of polar solvents were better than any single of them, except methanol. Paeonol and cupric bromide in mole ratio of 1∶2 in methanol under reflux temperature for five hours gave a bromination product in yield of 63.3%.

芍药酮的溴化反应

The bromination of paeonol with bromine and copper(Ⅱ)bromide was studied.The target compounds were different because of the different solvents.When paeonol was brominated with reagents like bromine in anhydrous diethyl ether and anhydrous aluminium trichloride,5bromo4methoxy2hydroxyacetophenone was obtained.The yield was 445%.Like cupric bromide in chloroformethyl acetate and anhydrous ethanol,the yield we obtained ωbromo4methoxy5bromo2hydroxyacetophenone was 475%.Paeonol was selectively brominated by copper(Ⅱ)bromide in anhydrous methanol(or chloroformethyl acetate)to give ωbromo4methoxy2hydroxyacetophenone in yield of 633%(or 487%).The structures of the target compounds were characterized by IR,1H NMR and MS.

取代1-吲酮的α-溴代反应

从取代3-苯丙酸出发，在多聚磷酸中直接环合（或先生成酰氯，再以三氯化铝催化环合）得到12个取代1-吲酮（Ⅰa～Ⅰl）。Ⅰ10mmol溶于40mL混合溶剂[V（乙酸乙酯）：V（氯仿）=1：1]中，搅拌下回流，分3批加入溴化铜（60％，24％和16％），经α-溴代反应得取代2-溴-1-吲酮（Ⅱa～Ⅱl，其中Ⅱf，Ⅱj，Ⅱk和Ⅱl未见文献报道），收率67．2％-91．5％。新化合物的结构经^1H NMR确证。

多羟基苯乙酮的α-溴化反应研究

α-卤代酮是有机合成的中间体,其一般的制备方法是在酸催化下,用卤素直接卤化,对于活泼的芳香酮。由于苯环被活化,所以易受到卤素的进攻,而生成卤代苯酮,因此选择性较差,King等人用溴化铜作为羟基苯乙酮的α-溴化试剂,发现有很好的选择性,只生成α-溴代产物。