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    PROCESS FOR THE PRODUCTION OF HIGH-PURITY TETRACHLORO -1,4-BENZOQUINONE
    2.
    发明专利
    PROCESS FOR THE PRODUCTION OF HIGH-PURITY TETRACHLORO -1,4-BENZOQUINONE 未知

    公开(公告)号：CA1313878C

    公开(公告)日：1993-02-23

    申请号：CA558255

    申请日：1988-02-05

    Applicant: HOECHST AG

    Inventor： ARNDT OTTO ,  PAPENFUHS THEODOR

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

    Abstract: of the disclosure HOE 87/F 066J A process for the production of high-purity tetrachloro1,4-benzoquinone by the action of chlorine and hydrochloric acid on hydroquinone which comprising causing 1.9 to 2.1 times the molar quantity of gaseous chlorine to act at temperatures from 5 to 15.degree.C on 1 mol of hydroquinone in 6 to 7 times the molar quantity of 30 to 37 % hydrochloric acid, then diluting the resulting suspension, essentially containing 2,5-dichlorohydroquinone, with 2 to 3 parts of water, relative to hydroquinone employed, and initially warming to a temperature from 20 to 30.degree.C, subsequently introducing 1.9 to 2.1 times the molar quantity of chlorine gas in an air atmosphere while raising the temperature to 90-100.degree.C with simultaneous dilution with 3.5 to 4.5 parts of water, relative to hydroquinone employed, and finally introducing 1 to 2 times the molar quantity of gaseous chlorine, relative to hydroquinone employed, at temperatures from 100 to 115.degree.C

    PROCESS FOR THE PRODUCTION OF HIGH-PURITY TETRACHLORO-1,4-BENZOQUINONE
    4.
    发明专利
    PROCESS FOR THE PRODUCTION OF HIGH-PURITY TETRACHLORO-1,4-BENZOQUINONE 未知

    公开(公告)号：IN166876B

    公开(公告)日：1990-07-28

    申请号：IN43CA1988

    申请日：1988-01-18

    Applicant: HOECHST AG

    Inventor： ARNDT OTTO ,  PAPENFUHS THEODOR

    IPC: C07C50/24 ,  C07C37/62 ,  C07C45/00 ,  C07C46/00 ,  C07C46/06 ,  C07C67/00 ,  C07C50/04

    Abstract: A process for the preparation of high-purity tetrachloro-1,4-benzoquinone by the action of hydrogen peroxide and hydrochloric acid on hydroquinone, which comprises causing 3.8 top 4.2 times the molar quantity of 30 to 37% hydrochloric acid and 1.9 to 2.1 times the molar quantity of 50 to 35% hydrogen peroxide, to act at 5 to 50 DEG C. on 1 mole of hydroquinone in at least 12 times the molar quantity of 30 to 37% hydrochloric acid, then heating the resulting suspension, which essentially contains 2,5-dichlorohydroquinone, to 45 to 55 DEG C. and again causing to act on it, at 50 to 95 DEG C., 3.8 to 4.2 times the molar quantity of 30 to 37% hydrochloric acid and 1.9 to 2.1 times the molar quantity of 50 to 35% hydrogen peroxide, in each case based on the hydroquinone used, and finally adding to the suspension, which is now essentially composed of trichloro-1,4-benzoquinone, 1.9 to 2.1 times the molar quantity of hydrochloric acid of the said concentration range, and 0.95 to 1.05 times the molar quantity of hydrogen peroxide of the said concentration range, in each case based on the hydroquinone used, at 95 to 115 DEG C., sufficiently slowly for no chlorine to escape.

    5.
    发明专利
    未知

    公开(公告)号：BR8108010A

    公开(公告)日：1982-09-21

    申请号：BR8108010

    申请日：1981-12-09

    Applicant: HOECHST AG

    Inventor： ARNDT OTTO ,  PAPENFUHS THEODOR ,  TRONICH WOLFGANG

    IPC: C07C261/04 ,  C07C261/00 ,  C07C273/06 ,  C07C275/30 ,  C07C127/19 ,  C07D207/26

    Abstract: Compounds of the formula I in which X denotes hydrogen, fluorine, chlorine or bromine, Y and Z denote hydrogen, lower alkyl or lower alkoxy, M denotes sodium, potassium or one equivalent of calcium and L denotes a dipolar aprotic solvent, are obtained from compounds of the formula II in which X, Y and Z have the abovementioned meanings, and a metal cyanamide of the formula III M2N-CN in which M has the abovementioned meaning, in a dipolar aprotic solvent, which after the reaction is substantially removed, whereupon a lower molecular weight aliphatic alcohol is added to the residue and the product precipitated is isolated. Nitrophenylureas of the formula IV in which X, Y and Z have the abovementioned meanings, are obtained from the compounds of the formula I by acid hydrolysis.

    7.
    发明专利
    未知

    公开(公告)号：DE59107698D1

    公开(公告)日：1996-05-23

    申请号：DE59107698

    申请日：1991-11-02

    Applicant: HOECHST AG

    Inventor： ARNDT OTTO ,  FUCHS HERMANN ,  GILB WALTER

    IPC: C07C227/08 ,  C07C229/62

    Abstract: An ecologically and economically improved process for the preparation of 2,5-di-phenylamino-terephthalic acid and its di-alkyl esters of the formula (1) (1) in which R is a hydrogen atom or a methyl group and R' is a hydrogen atom or a methyl or ethyl group.

    PROCESS FOR THE PREPARATION OF 2,5-DI(PHENYLAMINO)TEREPHTHALIC ACID AND ITS DIALKYL ESTERS IN HIGH PURITY
    8.
    发明专利
    PROCESS FOR THE PREPARATION OF 2,5-DI(PHENYLAMINO)TEREPHTHALIC ACID AND ITS DIALKYL ESTERS IN HIGH PURITY 未知

    公开(公告)号：CA2071107A1

    公开(公告)日：1992-12-15

    申请号：CA2071107

    申请日：1992-06-12

    Applicant: HOECHST AG

    Inventor： FUCHS HERMANN ,  GILB WALTER ,  ARNDT OTTO

    IPC: C07C227/06 ,  C07C227/08 ,  C07C229/58 ,  C07C229/62 ,  C07C227/16

    Abstract: HOE 91/F 175 Process for the preparation of 2,5-di(phenylamino)-terephthalic acid and its dialkyl esters in high purity A process for the preparation of 2,5di(phenylamino)terephthalic acid and its dialkyl esters of formula (I): (I) in which R is a hydrogen atom or a methyl group and R' is a hydrogen atom or a methyl or ethyl group, by (1) reacting a dialkyl(C1-C2) succinate with a sodium alcoholate in xylene, in the manner of a Dieckmann condensation, to give the disodium salt of the dialkyl (C1-C2)2,5-dihydroxycyclohexadiene-1,4-dicarboxylate, (2) reacting the resulting condensation product, after decomposition of the disodium salt with acid, with a phenylamine of formula (II): (II) in which R is as defined above, in the presence of an organic acid, in xylene, to give the dialkyl(C1-C2) 2,5di(phenylamino)-3,6-dihydroterephthalate, (3) dehydrogenating (oxidizing) the resulting 1,4-cyclohexadiene derivative with oxygen to give the corresponding dialkyl(C1-C2) 2,5-di(phenylamino)terephthalate, (4) saponifying the resulting dialkyl ester in methanolic sodium hydroxide solution to give the corresponding disodium 2,5-di(phenylamino)terephthalate, and (5) liberating the 2,5-di(phenylamino)terephthalic acid from said disodium salt with acid, which process comprises carrying out the oxidation in stage (3) in such a way that the reaction mixture of stage (2), in the form of a solution or suspension, is blanketed with nitrogen in a stirred vessel, this reaction mixture is circulated by pumping and the oxygen is metered into a partial volume of the circulated reaction mixture in such a way as to produce effective thorough mixing.

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