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    21.
    发明专利
    未知

    公开(公告)号：DE3867492D1

    公开(公告)日：1992-02-20

    申请号：DE3867492

    申请日：1988-02-03

    Applicant: HOECHST AG

    Inventor： ARNDT OTTO DR ,  PAPENFUHS THEODOR DR

    IPC: C07C37/62 ,  C07C45/00 ,  C07C46/00 ,  C07C46/06 ,  C07C50/24 ,  C07C67/00

    Abstract: In a new process for the prodn. of highly pure tetrachloro-1,4-benzoquinone by reaction of hydroquinone with chlorine and hydrochloric acid, (A) hydroquinone in 6 to 7 molar proportions of 30-37% hydrochloric acid is treated at 5-15 deg.C with 1.9-2.1 molar proportions of gaseous chlorine; (B) the resulting suspension (contg. essentially 2,5-dichlorohydroquinone) is diluted with 2-3 parts (based on hydroquinone used) of water and heated to 20-30 deg.C; (C) 1.9-2.1 molar proportions of chlorine gas are introduced under an atmos. of air while raising the temp. to 90-100 deg.C and diluting with 3.5-4.5 parts (based on hydroquinone used); and (D) 1-2 molar proportions of chlorine gas are introduced at 100-115 deg.C; molar proportion being based on the amt. of hydroquinone used.

    22.
    发明专利
    未知

    公开(公告)号：DE3677116D1

    公开(公告)日：1991-02-28

    申请号：DE3677116

    申请日：1986-09-24

    Applicant: HOECHST AG

    Inventor： ARNDT OTTO DR ,  PAPENFUHS THEODOR DR

    IPC: C07D209/92

    Abstract: Process for the preparation of naphthostyril by dissolving 1,8-naphthalimide in an aqueous solution of lithium hydroxide and potassium hydroxide while heating at 40 DEG C. to 80 DEG C., cooling the solution obtained to 14 DEG C. and seeding it at said temperature with a maximum of 1 mol-% of sodium 1,8-naphthalimide per 1 mol of 1,8-naphthalimide used, then adding chlorine bleaching liquor at 10 DEG C. to 20 DEG C., reductively removing excess active chlorine after the reaction has taken place, adjusting the alkaline aqueous solution produced of the alkali-metal salt of the 1-aminonaphthal-ene-8-carboxylic acid formed to a pH of 2.0 by adding acid and isolating the naphthostyril which precipitates in this process.

    25.
    发明专利
    未知

    公开(公告)号：DE3418495A1

    公开(公告)日：1985-11-21

    申请号：DE3418495

    申请日：1984-05-18

    Applicant: HOECHST AG

    Inventor： ARNDT OTTO DR ,  PAPENFUHS THEODOR DR

    IPC: C07C209/74 ,  C07C67/00 ,  C07C209/00 ,  C07C211/52 ,  C07C87/60 ,  C07C85/24

    Abstract: Process for the preparation of 2,6-dichloro-4-nitroaniline by chlorination of 4-nitroaniline with chlorine bleaching liquor in water using acids, which comprises chlorinating 1 mole of 4-nitroaniline in 3-6 moles of hydrochloric acid (HCl) or nitric acid (HNO3) in the form of a dilute, aqueous acid in the presence of a dispersing agent which is stable under the reaction conditions, the chlorination initially being carried out at 5 DEG to 10 DEG C. and then at 15 DEG -20 DEG C. and, finally, after 90-95% of the 2-chloro-4-nitroaniline intermediately formed has been converted into 2,6-dichloro-4-nitroaniline, the temperature of the aqueous suspension being increased from 15 DEG -20 DEG C. to 70 DEG C., without further addition of chlorine bleaching liquor, and then by post-chlorinating, by renewed addition of chlorine bleaching liquor, at temperatures between 20 DEG and 70 DEG C., bringing the pH of the aqueous suspension to 9.0 and filtering off the 2,6-dichloro-4-nitroaniline formed and washing it with dilute mineral acid.

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