通过咪唑酯的分子内傅克反应高效且可扩展地合成取代菲醌。

An efficient and scalable synthesis of substituted phenanthrenequinones by intramolecular Friedel-Crafts reaction of imidazolides.

作者信息

Yoshikawa Naoki, Doyle Austin, Tan Lushi, Murry Jerry A, Akao Atsushi, Kawasaki Masashi, Sato Kimihiko

机构信息

Department of Process Research, Merck Research Laboratories, Merck & Co., Inc., Rahway, New Jersey 07065, USA.

出版信息

Org Lett. 2007 Oct 11;9(21):4103-6. doi: 10.1021/ol071261h. Epub 2007 Sep 20.

DOI:10.1021/ol071261h

PMID:17880225

Abstract

An efficient synthesis of 9,10-phenanthrenequinones is described. The two carbonyl groups were introduced by an orthoselective intermolecular Friedel-Crafts reaction of 3-methoxyphenol with ethyl chlorooxoacetate. The formation of a biaryl bond by Suzuki-Miyaura coupling reaction, followed by the hydrolysis of the ester, gave a biaryloxoacetic acid. Treatment of this acid with CDI gave the corresponding imidazolide. The ring closure to the desired phenanthrenequinone was accomplished by intramolecular Friedel-Crafts reaction of the imidazolide promoted by TiCl(4).

摘要

本文描述了9,10-菲醌的高效合成方法。通过3-甲氧基苯酚与氯代氧代乙酸乙酯的邻位选择性分子间傅克反应引入两个羰基。经铃木-宫浦偶联反应形成联芳基键，随后酯水解，得到联芳基氧代乙酸。该酸与羰基二咪唑反应得到相应的咪唑化物。通过四氯化钛促进的咪唑化物的分子内傅克反应实现闭环生成所需的菲醌。