| 摘要 |
N-hydroxypyrazoles of the general formula I <IMAGE> (I) where R1, R2 and R3 may be identical or different and are each hydrogen, alkyl, halogen or aryl, or R1 and R2 or R2 and R3 together with the carbon atoms carrying these radicals form an aromatic or nonaromatic ring of 5 or 6 carbon atoms are prepared by a process in which (A) a pyrazole of the general formula II <IMAGE> (II) is converted in a conventional manner with an alkali metal hydroxide, alkali metal hydride or alkali metal carbonate into one of its metal salts of the general formula III <IMAGE> (III) where ME(+) is a cation of an alkali metal, and (B) the resulting metal salt of the general formula III is reacted with dibenzoyl peroxide in an inert organic solvent or in a 2-phase system, in the presence or absence of a phase transfer catalyst.
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