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    11.
    发明专利
    未知

    公开(公告)号：BR8900146A

    公开(公告)日：1989-09-12

    申请号：BR8900146

    申请日：1989-01-13

    Applicant: HOECHST AG

    Inventor： PLESSEN HELMOLD VON ,  RITTNER SIEGBERT ,  VOLK HEINRICH ,  WYKYPIEL WERNER ,  NEEB RUDOLF

    IPC: C07C51/00 ,  C07C51/43 ,  C07C65/11 ,  C07C67/00

    Abstract: A method for the purification of 2-hydroxynaphthalene-6-carboxylic acid by recrystallisation. In this method, the crude acid is recrystallised from water-miscible linear or cyclic aliphatic ethers, aliphatic polyethers or aliphatic hydroxy ethers or from an at least 10% strength by weight aqueous solution of these ethers. Recrystallisation from a 35-90% strength by weight aqueous solution of 1,4-dioxane is particularly preferred.

    12.
    发明专利
    未知

    公开(公告)号：MX149712A

    公开(公告)日：1983-12-14

    申请号：MX17424778

    申请日：1978-07-20

    Applicant: HOECHST AG

    Inventor： NEEB RUDOLF ,  MOHR REINHARD

    IPC: C09B44/00 ,  C09B44/20 ,  C09B69/06 ,  C09B39/00

    Abstract: Chlorozincate salts of benzothiazonium azo compounds are prepared by reacting benzothiazolium azo compounds with an dialkylsulfate having from 1 to 4 carbon atoms in the alkyl radicals, which process comprises carrying out the reaction in an aqueous medium at a temperature of from 10 DEG to 80 DEG C. in the presence of an acid acceptor and the alkylation with the use of from 1.8 to 2.5 mols of the dialkylsulfate, calculated on the starting azo dyestuff, at a pH not exceeding 7. The prepared benzothiazolium azo compound is precipitated as chlorozincate salt, especially with the use of an alkali metal chloride. According to this process, the chlorozincate salts are obtained in higher purity. A perceptible decomposition of the benzothiazolium azo compound does not occur. Chemicals, for example the alkylation agent and acid-binding agents need be used in a small quantity. In addition to this economy and to the less pollution of the waste water, the process has the advantage that it can be carried out with the use of a small reaction volume.

    15.
    发明专利
    未知

    公开(公告)号：IT1165307B

    公开(公告)日：1987-04-22

    申请号：IT2568179

    申请日：1979-09-12

    Applicant: HOECHST AG

    Inventor： NEEB RUDOLF ,  HOHMANN KURT ,  MOHR REINHARD

    IPC: C09B29/00 ,  C09B29/08 ,  C09B44/00 ,  C09B44/20 ,  C09B

    Abstract: Chlorozincate salts of thiazolium azo compounds are prepared by reacting thiazolium azo compounds with an dialkylsulfate having from 1 to 4 carbon atoms in the alkyl radicals, which process comprises carrying out the reaction in an aqueous medium at a temperature of from about 10 DEG to 50 DEG C. in the presence of a zinc compound capable of binding acid, and with the use of from 1.8 to 2.5 mols of the dialkylsulfate, calculated on the starting azo dyestuff, at a pH not exceeding 8, preferably at 3-7. The prepared thiazolium azo compound is precipitated as chlorozincate salt, especially by means of an alkali metal chloride. According to this process, the chlorozincate salts are obtained in higher purity. A perceptible decomposition of the thiazolium azo compound does not occur. Chemicals, for example the alkylation agent and acid-binding agents need be used in a small quantity. In addition to this economy and to the less pollution of the waste water, the process has the advantage that it can be carried out with the use of a small reaction volume.

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