Preparation of optically active .alpha.-(hydroxyphenoxy)alkanecarboxylic
acids and derivatives thereof
    31.
    发明授权
    Preparation of optically active .alpha.-(hydroxyphenoxy)alkanecarboxylic acids and derivatives thereof 失效
    光学活性α-(羟基苯氧基)烷羧酸及其衍生物的制备

    公开(公告)号:US5654338A

    公开(公告)日:1997-08-05

    申请号:US428710

    申请日:1995-04-25

    Inventor: Pascal Metivier

    CPC classification number: C07C51/367 C07C67/31

    Abstract: Optically active .alpha.-(hydroxyphenoxy)-alkanecarboxylic acids or derivatives thereof, for example D-2-(4-hydroxyphenoxy)propionic acid or lower alkyl ester thereof, are prepared by (a) saponifying an alkyl ester of an optically active .alpha.-halogeno-alkanecarboxylic acid, in an alcoholic solvent medium, by reacting same with an aqueous solution of an alkali metal hydroxide, thereby providing a solution of an alkali metal salt of an optically active .alpha.-halogeno-alkanecarboxylic acid, (b) next reacting the step (a) solution thus provided with a dihydroxybenzene or salt thereof, in the presence of an alkali metal hydroxide and in an alcoholic solvent medium, and thence (c) recovering the optically active .alpha.-(hydroxyphenoxy)-alkanecarboxylic acid or derivative thereof from the medium of reaction.

    Abstract translation: 光学活性α-(羟基苯氧基) - 烷羧酸或其衍生物,例如D-2-(4-羟基苯氧基)丙酸或其低级烷基酯通过以下方法制备:(a)皂化光学活性α-卤代的烷基酯 - 烷醇羧酸,在醇溶剂介质中,通过与碱金属氢氧化物的水溶液反应,从而提供光学活性α-卤代 - 链烷羧酸的碱金属盐的溶液,(b)接下来使步骤 (a)在碱金属氢氧化物和醇溶剂介质的存在下提供二羟基苯或其盐的溶液,然后(c)从光学活性α-(羟基苯氧基) - 烷羧酸或其衍生物从 反应介质

    Process for the preparation of brominated compounds, especially from
alcohols
    32.
    发明授权
    Process for the preparation of brominated compounds, especially from alcohols 失效
    制备溴化化合物,特别是醇的方法

    公开(公告)号:US5241086A

    公开(公告)日:1993-08-31

    申请号:US985756

    申请日:1992-12-04

    CPC classification number: C07D309/04 C07B39/00 C07C17/16 C07C29/62

    Abstract: A process for the preparation of a brominated compound which comprises the step of reacting at least one compound selected from the group consisting of a chloroformate, a chlorosulfite and a chlorophosphite with a brominating agent for a time sufficient to obtain at least one brominated compound. In particular, an alcohol is converted into a chloroformate, chlorosulfite or a chlorophosphite, which is then brominated to obtain the desired product. In another embodiment, a brominating agent is reacted with a reactant selected from the group consisting of thionyl chloride, phosgene and phosphorous oxychloride, followed by contacting the reaction product obtained with an alcohol to be brominated.

    Abstract translation: 一种制备溴化化合物的方法,其包括使选自氯甲酸酯,亚硫酸氢盐和氯代亚磷酸酯的至少一种化合物与溴化剂反应一段时间以获得至少一种溴化化合物的步骤。 特别地,将醇转化为氯甲酸酯,亚硫酸氢盐或氯代亚磷酸酯,然后将其溴化以获得所需产物。 在另一个实施方案中,将溴化剂与选自亚硫酰氯,光气和三氯氧化磷的反应物反应,然后使得到的待反应产物与待溴化的醇接触。

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