97.
    发明专利
    未知

    公开(公告)号:DE50308226D1

    公开(公告)日:2007-10-31

    申请号:DE50308226

    申请日:2003-05-12

    Applicant: BASF AG

    Abstract: Production of 2-(4-N,N-dialkylamino-2-hydroxybenzoyl)benzoic acid esters comprises reaction of a 3-N,N-dialkylaminophenol with phthalic acid anhydride to form a 2-(4-N,N-dialkylamino-2-hydroxybenzoyl)benzoic acid, esterification with a 1-12C alcohol or cyclic 3-10 C alcohol in the presence of an acid catalyst. A process for the production of 2-(4-N,N-dialkylamino-2-hydroxybenzoyl)benzoic acid esters (I) of formula (1) comprises: (a) reaction of a 3-N,N-dialkylaminophenol of formula (2) with phthalic acid anhydride to form a 2-(4-N,N-dialkylamino-2-hydroxybenzoyl)benzoic acid of formula (3) followed by; (b) esterification with a 1-12C alcohol or cyclic 3-10 C alcohol in the presence of an acid catalyst to form the ester (I) of formula (1) whereby the product ester is purified in a step; (c) by treatment with an adsorbent and/or by distillation. R1, R2 = 1-6C alkyl or 3-10C cycloalkyl; R3 = 1-12C alkyl or 3-10C cycloalkyl.

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