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    • 10. 发明授权
    • Preparation of N-hydroxypyrazoles
    • N-羟基吡唑的制备
    • US4945167A
    • 1990-07-31
    • US367047
    • 1989-06-16
    • Ulf BausWolfgang ReutherErwin Hahn
    • Ulf BausWolfgang ReutherErwin Hahn
    • C07D231/12C07D231/16C07D521/00
    • C07D231/12C07D231/16C07D233/56C07D249/08
    • N-hydroxypyrazoles of the general formula I ##STR1## where R.sup.1, R.sup.2 and R.sup.3 may be identical or different and are each hydrogen or halogen, are prepared by a process in which a pyrazole of the general formula II ##STR2## where R.sup.1, R.sup.2 and R.sup.3 have the meanings stated for formula I, is reacted with an aliphatic or aromatic peroxocarboxylic acid, preferably in the presence of from 0 to 15 moles of an alkali metal hydroxide, alkaline earth metal hydroxide, alkali meteal carbonate or alkaline earth metal carbonate in such a way that the reaction temperature is from -5.degree. C. to 60.degree.C.The reaction can be carried out in water as a solvent or in a 2-phase system consisting of water and an inert organic solvent which is poorly miscible with water, in the presence or absence of a suitable phase transfer catalyst. The peroxocarboxylic acid can be prepared in the reaction mixture before the reaction from H.sub.2 O.sub.2 and an acyl halide or a carboxylic anhydride or can be used in the form of an alkali metal salt or alkaline earth metal salt.
    • 其中R 1,R 2和R 3可以相同或不同并且各自为氢或卤素的通式I(I)的N-羟基吡唑通过其中通式II的吡唑(IMAGE)( II)其中R 1,R 2和R 3具有式I所述的含义,与脂族或芳族过氧羧酸反应,优选在0至15摩尔碱金属氢氧化物,碱土金属氢氧化物,碱金属碳酸盐 或碱土金属碳酸盐,使得反应温度为-5℃至60℃。该反应可以在作为溶剂的水中或在由水和惰性有机物组成的2相体系中进行 在有或没有合适的相转移催化剂的情况下与水很难混溶的溶剂。 过氧化羧酸可以在与H 2 O 2和酰卤或羧酸酐反应之前在反应混合物中制备,或者可以以碱金属盐或碱土金属盐的形式使用。