Patent ID: 6040458
Filing Date: 2000-03-21
Classification: C07D

Abstract:
A process for preparing N-substituted 3-hydroxypyrazoles of the formula I ##STR6## where R.sup.1 is unsubstituted or substituted C.sub.1 -C.sub.10 -alkyl, C.sub.2 -C.sub.10 -alkenyl, C.sub.2 -C.sub.10 -alkynyl, C.sub.3 -C.sub.10 -cycloalkyl, unsubstituted or substituted aryl selected from phenyl and naphthyl; heteroaryl selected from furyl, thienyl, pyrrolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxazolyl, imidazolyl, pyridyl, pyridazinyl, pyrimidinyl and triazinyl; andR.sup.2, R.sup.3 are hydrogen, cyano, halogen and unsubstituted or substituted C.sub.1 -C.sub.10 -alkyl, C.sub.2 -C.sub.10 -alkenyl, C.sub.2 -C.sub.10 -alkynyl, C.sub.3 -C.sub.10 -cycloalkyl; unsubstituted or substituted aryl selected from phenyl and naphthyl; heteroaryl selected from furyl, thienyl, pyrrolyl, isoxazolyl, isothiazolyl, pyrazolyl, oxazolyl, imidazolyl, pyridyl, pyridazinyl, pyrimidinyl and triazinyl;where the substituents R.sup.1, R.sup.2 and R.sup.3 are inert under the reaction conditions,by oxidizing a pyrazolidin-3-one of the formula II ##STR7## which comprises carrying out the reaction of the water-soluble compounds of the formula II in water in the presence of a base using oxygen as oxidizing agent.