Process for the preparation of hydrazine derivatives

摘要

Process for the preparation of hydrazine derivatives of the formula I in which Ar is optionally substituted phenyl, optionally substituted naphthyl or a five- or six-membered aromatic heterocyclic radical and R<1> and R<2> in each case have the meaning given in the description, by reacting a hydroxamic acid derivative of the formula II in which Ar has the abovementioned meaning and R<3> is C1-C8-alkyl or the abovementioned radical Ar, with an amine of the formula III in which R<1> and R<2> in each case have the abovementioned meaning, at a temperature of 20 to 80@C.