Method for producing N-substituted 3-hydroxypyrazoles

摘要

PCT No. PCT/EP97/06780 Sec. 371 Date Jun. 14, 1999 Sec. 102(e) Date Jun. 14, 1999 PCT Filed Dec. 4, 1997 PCT Pub. No. WO98/27062 PCT Pub. Date Jun. 25, 1998A process is described for preparing N-substituted 3-hydroxypyrazoles of the formula I where R1 is unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl or heteroaryl and R2, R3 are hydrogen, cyano, halogen and unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl or heteroaryl, by oxidizing a corresponding pyrazolidin-3-one.