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    PRODUCTION OF 2,4-DIMETHYLPYRROLE
    1.
    发明专利
    PRODUCTION OF 2,4-DIMETHYLPYRROLE 失效

    公开(公告)号：JP2000178250A

    公开(公告)日：2000-06-27

    申请号：JP35933999

    申请日：1999-12-17

    Applicant: BASF AG

    Inventor： GROENING CARSTEN DR ,  KEMPER REINHARD ,  FREDE MARKUS DR ,  EBEL KLAUS DR

    IPC: C07D207/32 ,  C07D207/323

    Abstract: PROBLEM TO BE SOLVED: To produce 2,4-dimethylpyrrole under much milder conditions of slighter aggressiveness thin well-known conditions according to a conventional technique. SOLUTION: A dicarboxylic acid alkyl ester which is a 2,4-dimethyl-3,5- bisalkoxycarbonylpyrrole is refluxed together with an aqueous solution of an alkali metal hydroxide at 10-30% concentration, advantageously a sodium hydroxide solution until a solid is converted into a solution and the reactional mixture is then neutralized with an acid and further refluxed until the decarbocylation is completed, i.e., the gas evolution is stopped.

    PRODUCTION OF 2,4-DIMETHY-3,5-BISALKOXYCARBONYLLPYRROLE
    2.
    发明专利
    PRODUCTION OF 2,4-DIMETHY-3,5-BISALKOXYCARBONYLLPYRROLE 失效

    公开(公告)号：JP2000178251A

    公开(公告)日：2000-06-27

    申请号：JP35934099

    申请日：1999-12-17

    Applicant: BASF AG

    Inventor： GROENING CARSTEN DR ,  KEMPER REINHARD ,  FREDE MARKUS DR ,  EBEL KLAUS DR

    IPC: C07D241/06 ,  B01J23/44 ,  C07B61/00 ,  C07D207/34

    Abstract: PROBLEM TO BE SOLVED: To produce a 2,4-dimethyl-3,5-bisalkoxycarbonylpyrrole by enabling operations under milder conditions than those of a conventional technique and avoidance of the formation of by-products. SOLUTION: An alkyl acetoacetate is nitrosated to produce an alkyl 2- nitrosoacetoacetate, which is then reduced with hydrogen in the presence of a noble metal catalyst to form an amine. The resultant amino compound without isolation is condensed in the presence of the corresponding alkyl acetoacetate without undergoing the nitrosation to produce 2,4-dimethyl-3,5- bisalkoxycarbonylpyrrole.

    8.
    发明专利
    未知

    公开(公告)号：DE19858360A1

    公开(公告)日：2000-06-21

    申请号：DE19858360

    申请日：1998-12-17

    Applicant: BASF AG

    Inventor： GROENING CARSTEN ,  KEMPER REINHARD ,  FREDE MARKUS ,  EBEL KLAUS

    IPC: C07D207/32 ,  C07D207/323 ,  C07D207/416

    Abstract: In the preparation of 2,4-dimethyl-pyrrole (I) by hydrolysis of 2,4-dimethyl-3,5-bis-alkoxycarbonyl-pyrrole (II) to the dicarboxylic acid (III) with strong alkali and thermal decarboxylation of (III), (II) is heated under reflux with 10-30% aqueous alkali hydroxide, and then neutralized with acid. Heating under reflux is continued to complete decarboxylation.

    9.
    发明专利
    未知

    公开(公告)号：DE19858352A1

    公开(公告)日：2000-06-21

    申请号：DE19858352

    申请日：1998-12-17

    Applicant: BASF AG

    Inventor： GROENING CARSTEN ,  KEMPER REINHARD ,  FREDE MARKUS ,  EBEL KLAUS

    IPC: C07D241/06 ,  B01J23/44 ,  C07B61/00 ,  C07D207/34 ,  C07D207/416

    Abstract: In the preparation of 2,4-dimethyl-3,5-bis-alkoxycarbonyl-pyrroles (I) by nitrosing an alkyl acetoacetate (II) to the alkyl 2-nitrosoacetoacetate (III), reducing (III) to the amine (IV) and ring-closing condensation with unsubstituted (II), (III) is hydrogenated with hydrogen in the presence of a noble metal catalyst and condensed with (II) without isolating (IV).

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