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    Preparation of 3-arylacrylic acids and their derivatives
    41.
    发明授权
    Preparation of 3-arylacrylic acids and their derivatives 失效
    3-芳基丙烯酸及其衍生物的制备

    公开(公告)号：US5359122A

    公开(公告)日：1994-10-25

    申请号：US193872

    申请日：1994-02-08

    Applicant: Michael Huellmann ,  Josef Gnad ,  Rainer Becker

    Inventor： Michael Huellmann ,  Josef Gnad ,  Rainer Becker

    IPC: C07C57/44 ,  C07C59/64 ,  C07C67/46 ,  C07C69/734

    CPC classification number: C07C59/64 ,  C07C57/44 ,  C07C67/46

    Abstract: The preparation of 3-arylacrylic acids and their derivatives I ##STR1## where Ar is aryl which can additionally have substituents which do not react with ketene and are stable under the conditions of the reaction described below, andR.sup.1 is hydrogen, an alkali metal, an alkaline earth metal, ammonium or C.sub.1 -C.sub.20 -alkyl,comprises a first stage in which a dialkyl acetal of an aromatic aldehyde of the formula II ##STR2## where R.sup.2 is C.sub.1 -C.sub.4 -alkyl, is reacted with ketene of the formula CH.sub.2 .dbd.C.dbd.O in the presence of catalytic amounts of a protic or Lewis acid to give a 3-arylpropionic acid derivative of the formula III ##STR3## and a second stage in which this intermediate III is reacted in the presence of acid or base and, in the case where R.sup.1 is C.sub.1 -C.sub.20 -alkyl, additionally with a C.sub.1 -C.sub.20 -alkanol to give the final product I.

    Abstract translation: 3-芳基丙烯酸及其衍生物的制备I（I）其中Ar是可以另外具有不与乙烯酮反应并且在下述反应条件下稳定的取代基的芳基，R 1是氢， 碱金属，碱土金属，铵或C 1 -C 20烷基，包括其中R 2为C 1 -C 4 - 烷基的式II的芳族醛的二烷基缩醛反应的第一阶段 在催化量的质子或路易斯酸存在下，式CH 2 = C = O的烯酮，得到式III的3-芳基丙酸衍生物（III），其中该中间体III为 在酸或碱的存在下反应，在R1为C1-C20烷基的情况下，另外加入C1-C20链烷醇，得到最终产物I.

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