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公开(公告)号：DE2522175A1
公开(公告)日：1976-11-25
申请号：DE2522175
申请日：1975-05-17
Applicant: HOECHST AG
Inventor： BACHMANN WILFRIED DIPL ING DR , GNABS CHRISTIAN DIPL ING DR , JANECKA KURT DIPL CHEM DR , MUNDLOS EBERHARD DIPL CHEM DR , PAPENFUHS THEODOR DIPL CHEM DR , WAESE GERHARD DIPL CHEM DR
Abstract: 2-Hydroxy-3-naphthoic acid (I) is prepared by reacting carbon dioxide on alkali metal salts of beta-naphthol in the presence of beta-naphthol at high temp. and pressure and the reaction is carried out being subjected to a continuous shearing action in time and space. (I) is an intermediate partic. used in the production of dyes. Previous dry processes have been slow (30-35 hrs) with difficult heat transfer and resinous by-products are formed. The above process reduces the amount of resins formed giving yields of 50-60% based on the alkali metal naphthalate used, also the reaction time is shorter and lower pressures may be used.
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公开(公告)号：DE2426852A1
公开(公告)日：1976-01-02
申请号：DE2426852
申请日：1974-06-04
Applicant: HOECHST AG
Inventor： BACHMANN WILFRIED DIPL ING , GNABS CHRISTIAN DIPL ING , JANECKA KURT DIPL ING DR , MUNDLOS EBERHARD DIPL CHEM DR , PAPENFUHS THEODOR DIPL CHEM DR , WAESE GERHARD DIPL CHEM DR
Abstract: An improved process for isolating 2-hydroxynaphthalenecarboxylic acids from reaction mixtures of the alkali metal salts of the 2-hydroxynaphthalene with carbon dioxide had been found which comprises diluting with water the reaction mixture which contains the di-alkali metal salt of 2-hydroxynaphthalenecarboxylic acid and 2-hydroxynaphthalene, while keeping the mixture at a temperature of at least 80 DEG C, then adjusting the pH-value to about 6 to 7 by means of aqueous mineral acid, separating the lower phase at at least 80 DEG C, cooling the upper phase to about 15 DEG to 25 DEG C, separating the 2-hydroxynaphthalene, then adjusting the pH-value to about 1 to 2 by means of aqueous mineral acid and isolating the separated 2-hydroxynaphthalenecarboxylic acid. By this novel process, work intensive operations, expensive technical apparatuses which are suspectible to repairs, solvents which do not participate directly in the reaction and therewith complicated regenerations, as known from the present art, are completely avoided. It permits clear and very easy separation of the reaction products at only one and the same stage in the process and allows in advantageous manner continuous operation.
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公开(公告)号：DE2426850A1
公开(公告)日：1976-01-02
申请号：DE2426850
申请日：1974-06-04
Applicant: HOECHST AG
Inventor： BACHMANN WILFRIED DIPL ING , GNABS CHRISTIAN DIPL ING , JANECKA KURT DIPL CHEM DR , MUNDLOS EBERHARD DIPL CHEM DR , PAPENFUHS THEODOR DIPL CHEM DR , WAESE GERHARD DIPL CHEM DR
Abstract: 2-Hydroxy-3-naphthoic acid (I) is prepared by reacting carbon dioxide on alkali metal salts of beta-naphthol in the presence of beta-naphthol at high temp. and pressure and the reaction is carried out being subjected to a continuous shearing action in time and space. (I) is an intermediate partic. used in the production of dyes. Previous dry processes have been slow (30-35 hrs) with difficult heat transfer and resinous by-products are formed. The above process reduces the amount of resins formed giving yields of 50-60% based on the alkali metal naphthalate used, also the reaction time is shorter and lower pressures may be used.
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