A Mannich base intermediate for 2-[(4-heterocyclic-phenoxymethyl)-phenoxyl]-alkanoates and methods for its preparation are provided. A method for preparation of an alkyl 2-[2-(secondary amino methyl)-5-alkylphenoxy]-alkanoate comprises the steps of: reacting a mixture of m-alkyl phenol, a secondary amine, and an aldehyde, with or without a catalyst, in a first solvent at reflux temperatures to form a 2-[(secondary amino)methyl]-5-alkylphenol. That product is then reacted with an alkyl 2-haloalkanoate, and an alkali metal carbonate, with or without a second catalyst in a second solvent at reflux temperatures to form the 2-[2-(secondary amino methyl)-5-alkylphenoxy]-alkanoate. The aldehyde may be paraformaldehyde, aqueous formaldehyde, formaldehyde, or polymerized acetal derivatives thereof. The first solvent may be acetonitrile or toluene. The catalyst may be an acid catalyst or a base catalyst. In the preferred embodiment the Mannich base is a 2-[(secondary amino)-methyl]-5-alkylphenol, or a 2-[2-(secondary amino methyl)-5-alkylphenoxy]-alkanoate.
本发明提供了用于2-[(4-杂环芳基甲氧基)-芳基甲氧基]-
脂肪酸酯的Mannich碱中间体及其制备方法。制备烷基2-[2-(二级
氨基甲基)-5-烷基苯氧基]-
脂肪酸酯的方法包括以下步骤:在第一种溶剂中,将m-烷基
酚、二级胺和醛混合物反应,可以加催化剂,反应温度为回流温度,形成2-[(二级
氨基)甲基]-5-烷基
苯酚。然后将该产物与烷基2-卤代
脂肪酸酯和碱
金属
碳酸盐混合物反应,可以加第二催化剂,反应温度为回流温度,形成2-[2-(二级
氨基甲基)-5-烷基苯氧基]-
脂肪酸酯。醛可以是多聚
乙醛、
水合甲醛、
甲醛或其聚合
缩醛衍
生物。第一种溶剂可以是
乙腈或
甲苯。催化剂可以是酸性催化剂或碱性催化剂。在首选实施例中,Mannich碱是2-[(二级
氨基)甲基]-5-烷基
苯酚或2-[2-(二级
氨基甲基)-5-烷基苯氧基]-
脂肪酸酯。