发明授权
US06444828B1 Method for preparing 1-alkyl-pyrazol-5-carboxylic acid esters III
有权
1-烷基 - 吡唑-5-羧酸酯的制备方法
- 专利标题： Method for preparing 1-alkyl-pyrazol-5-carboxylic acid esters III
- 专利标题（中）： 1-烷基 - 吡唑-5-羧酸酯的制备方法
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申请号： US09762626申请日： 2001-02-09
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公开(公告)号： US06444828B1公开(公告)日： 2002-09-03
- 发明人: Nikolaus Müller , Michael Matzke
- 申请人： Nikolaus Müller , Michael Matzke
- 优先权： DE19837067 19980817
- 主分类号： C07D23110
- IPC分类号： C07D23110
摘要：
1-Alkyl-pyrazole-5-carboxylic esters are obtained with surprisingly low proportions of 1-alkyl-pyrazole-3-carboxylic esters if a 2,4-diketo ester and/or an enolate thereof is reacted with an alkylhydrazine and/or a corresponding alkylhydrazinium salt, if appropriate, in the presence of a solvent and/or of water, in such a manner that during at least about 90% of the reaction free alkylhydrazine is present.
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