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通过海因〔hydantoin〕合成氨基酸是制备各种氨基酸的重要途径之一。研究、探讨海因的关环机理、催化剂及反应条件在氨基酸化学中有重要的理论意义和实用价值。我们结合蛋氨酸的制备对其中间体5-(β-甲硫基乙基)海因(简称海因)的合成进行了研究,取得了较为满意的结果。海因合成一般分为两步法和一步法。两步法是在催化剂存在下先使丙烯醛与甲硫醇反应生成β-甲硫基丙醛(简称M-醛),然后再使M-醛与氢氰酸或氰化钠及碳酸氢铵反应制备海
Synthesis of amino acids by hydantoin is one of the important ways to prepare various amino acids. Studying and discussing the mechanism of the ring closure of the hydantoin, the catalyst and the reaction conditions have important theoretical significance and practical value in the amino acid chemistry. We combined methionine preparation of its intermediate 5- (β-methylthioethyl) hydantoin (referred to as Hein) synthesis has been studied, and achieved satisfactory results. Hein synthesis is generally divided into two-step method and one-step method. In the two-step method, acrolein is first reacted with methanethiol to form β-methylthiopropanal (M-aldehyde) in the presence of a catalyst, and then M-aldehyde is reacted with hydrocyanic acid or sodium cyanide and ammonium bicarbonate The reaction preparation of the sea