有机化学 ›› 2013, Vol. 33 ›› Issue (05): 1047-1056.DOI: 10.6023/cjoc201211009 上一篇    下一篇

研究论文

N-[3-(4-甲基苯基)-3-氧代-1-芳基丙基]乙酰胺的三氟乙酸催化合成

任正红, 李晟, 张兴花, 范莉, 周光明, 杨大成   

  1. 西南大学化学化工学院 重庆 400715
  • 收稿日期:2012-11-07 修回日期:2012-12-13 发布日期:2013-01-07
  • 通讯作者: 范莉,hxfanl@swu.edu.cn,杨大成,hxydc@swu.edu.cn E-mail:hxfanl@swu.edu.cn;hxydc@swu.edu.cn
  • 基金资助:

    重庆市科技攻关计划(Nos. 2011AB5001, 2011AC1053)、国家自然科学基金(No. 21172181)、中央高校基本科研业务费专项资金(No. XDJK2010C067)资助项目.

One-Pot Synthesis of N-[3-(4-Methylphenyl)-3-oxo-1-arylpropyl]ace-tamides Employing Trifluoroacetic Acid as an Efficient Catalyst

Ren Zhenghong, Li Sheng, Zhang Xinghua, Fan Li, Zhou Guangming, Yang Dacheng   

  1. School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715
  • Received:2012-11-07 Revised:2012-12-13 Published:2013-01-07
  • Supported by:

    Project supported by the Chongqing Science and Technology Research Project (Nos. 2011AB5001, 2011AC1053), the National Natural Science Foundation of China (No. 21172181) and the Fundamental Research Funds for the Central Universities (No. XDJK2010C067).

以对甲基苯乙酮、芳香醛和乙腈为主要原料, 通过三氟乙酸催化的改进的Dakin-West反应, 顺利得到28个N-[3-(4-甲基苯基)-3-氧代-1-芳基丙基]乙酰胺, 最高收率可达95%. 18个新化合物的结构经1H NMR, 13C NMR和HRMS证实. 结构测试发现, 羟基苯甲醛参与Dakin-West反应后得到的全部是羟基乙酰化的产物. 作者首次证实, 羟基苯甲醛参与的Dakin-West反应不是串联反应, 而是羟基苯甲醛首先经TFA催化转化为乙酰氧基苯甲醛, 然后参与Dakin-West反应, 最终生成羟基乙酰化产物. 通过碱性水解, 可以选择性高收率地制备对应的羟基化β-乙酰氨基酮, 同时也反证了羟基乙酰化产物的存在. 该研究扩展了TFA催化的Dakin-West反应, 为β-乙酰氨基酮的合成提供了新的方法.

关键词: Dakin-West反应, 多组分反应, 三氟乙酸, β-乙酰氨基酮, 对甲基苯乙酮, 芳香醛

The synthesis of a series of N-[3-(4-methylphenyl)-3-oxo-1-arylpropyl]acetamides using trifluoroacetic acid (TFA) as the catalyst was reported in this paper. It was achieved by a modified Dakin-West reaction using 4-methylacetophenone, aromatic aldehydes and acetonitrile as starting materials. The highest yield was up to 95% among the twenty eight target compounds synthesized. All the new compounds were characterized by 1H NMR, 13C NMR and HRMS spectra. This one-pot reaction offered several advantages including small catalyst loading (0.3 mol%), moderate reaction temperatures (28~35 ℃) and simple post treatment procedure. A reaction mechanism was for the first time established, in which hydroxybenzaldehyde was first catalytically converted into corresponding acetoxybenzaldehyde prior to be involved in the subsequent Dakin-West reaction that eventually led to hydroxyl acetylated target compounds. The resultant hydroxyl acetylated β-acetamido ketones were selectively deacetylated in LiOH to produce the corresponding hydroxyl products with excellent yields. The current work further demonstrated that TFA was an efficient catalyst for Dakin-West reaction involving arylalkyl ketones, aromatic aldehydes and acetonitrile, which expanded significantly the scope of the substrates and provided a new synthetic route to β-acetamido ketones.

Key words: Dakin-West reaction, multi-component reaction, trifluoroacetic acid, β-acetamido ketone, 4-methylacetophenone, aromatic aldehyde