PRODUCTION OF 2,4-DIMETHYLPYRROLE

    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

    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

    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

    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

    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

    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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