| abstract |
N-Hydroxyazoles of the general formula I <IMAGE> (I) where A is <IMAGE> <IMAGE> and R1, R2 and R3 are each hydrogen, C1-C4-alkyl or halogen, are prepared by a process in which an azole of the general formula II <IMAGE> (II) where A, R1, R2 and R3 have the abovementioned meanings, is reacted with hydrogen peroxide or an alkyl peroxide in the presence of a zeolite catalyst at from -20 DEG to 150 DEG C. and from 0.1 to 150 bar. |