Method for producing nitroguanidine derivatives

A process for the preparation of compounds of formulais described, whereinR1 is hydrogen or C1-C4-alkyl;R2 is hydrogen, C1-C6-alkyl, C3-C6-cycloalkyl or a radical -CH2B;A is an unsubstituted or mono- to penta-substituted, aromatic or non-aromatic, monocyclic to bicyclic heterocyclic radical; andB is phenyl, 3-pyridyl or thiazolyl, which are optionally substituted by one to rhee substituents;by means of the hydrolysis of a compound of formulawherein R1, R2 and A have the same significances as given for formula (I), and R3 signifies unsubstituted or substituted C1-C10-alkyl, C3-C6-cycloalkyl, phenyl or benzyl; whereby the reaction is carried out at a pH value of between 7 and 14, as well as starting materials for carrying out the process.The compounds of formula (I) are suitable as intermediates in the preparation of pesticidal compositions.