Process for obtaining 2-hydroxy-4-methylthiobutyric acid (MHA)
    7.
    发明授权
    Process for obtaining 2-hydroxy-4-methylthiobutyric acid (MHA) 有权
    获得2-羟基-4-甲硫基丁酸(MHA)的方法

    公开(公告)号:US6140536A

    公开(公告)日:2000-10-31

    申请号:US91796

    申请日:1998-09-01

    CPC分类号: C07C319/28 C07C319/20

    摘要: A method for the isolation of 2-hydroxy-4-methylthiobutyric acid (MHA), wherein MHA is isolated from a reaction mixture obtained by addition of hydrogen cyanide (HCN) to methylmercaptopropionaldehyde (MMP) and hydrolysis by sulphuric acid of the methylmercaptopropionaldehyde cyanohydrin (MMP-CH) thus obtained. The reaction mixture is brought into contact in a liquid/liquid extraction system with an organic solvent substantially immiscible with water, in order to form an extraction solution which contains the solvent and the MHA transferred out of the reaction mixture. By bringing the salt content of the reaction mixture, prior to the liquid/liquid extraction, to a concentration of about >50 wt. % (wt./wt.), preferably >55 wt. %, referred to the sum of the inorganic constituents of the reaction mixture, the coordinated use of energy in the total system is improved, the evaporation of strongly corrosive solutions is avoided, the efficiency of the hydrolysis step is increased and the distribution coefficients during the extraction are improved. The MHA is isolated as the extract from this extraction solution by evaporation, and may be used as animal feed supplement.

    摘要翻译: PCT No.PCT / EP96 / 05437 Sec。 371日期:1998年9月1日 102(e)1998年9月1日PCT PCT 1996年12月5日PCT公布。 公开号WO97 / 23452 日期1997年7月3日分离2-羟基-4-甲硫基丁酸(MHA)的方法,其中MHA是通过将氰化氢(HCN)加入到甲基巯基丙醛(MMP)中并通过硫酸水解而获得的反应混合物中分离的 的甲基巯基丙醛氰醇(MMP-CH)。 使反应混合物在液/液萃取系统中与基本上与水不混溶的有机溶剂接触,以形成含有溶剂和从反应混合物中转移的MHA的萃取溶液。 通过使液体/液体萃取之前的反应混合物的盐含量达到约> 50wt。 %(重量/重量),优选> 55重量% %,是指反应混合物的无机成分之和,改善了总体系中能量的协调使用,避免了强腐蚀性溶液的蒸发,提高了水解步骤的效率,提高了分散系数 提取提高。 通过蒸发将MHA作为来自该提取溶液的提取物分离,并且可以用作动物饲料添加剂。