The invention relates to 2-(2-pyridyl)-5-phenyl-6-aminopyrimidines of formula I, wherein the substitutes and the index have the following meaning: R1 represents halogen, hydroxy, hyano, hxo, nitro, amino, mercapto, alkyl, halogenalkyl, alkenyl, alkinyl, cycloalkyl, alkoxy, halogenalkoxy, carboxyl, alkoxycarbonyl, carbamoyl, alkylaminocarbonyl, dialkylamincarbonyl, morpholinocarbonyl, pyrrolidinocarbonyl, alkylcarbonylamino, alkylamino. dialkylamino, alkylthio, alkylsulfinyl, alkylsulfonyl, hydroxysulfonyl, aminosulfonyl, alkylaminosulfonyl, dialkylaminosulfonyl; m=0 or 1-4; R2 represents hydrogen, halogen, cyano, alkyl, halogenalkyl or alkoxy; R3, R4 represents hydrogen, alkyl, halogenalkyl, cycloalkyl, halogencycloalkyl, alkenyl, halogenalkenyl, cycloalkenyl, alkinyl, halogenalkinyl or cycloalkinyl, R3 and R4 together with the nitrogen atom to which they are connected, form a five or six-membered ring which is interrupted by an atom from the group O, N or S and/or can be substituted according to the description; R5 represents halogen, alkyl or halogenalkyl; R6 represents hydrogen or one of the known groups in R5; R7, R8 represent hydrogen, halogen, alkyl or halogenalkyl; R9 represents hydrogen, halogen, hydroxy, cyano, alkyl, alkoxy, cycloalkoxy, halogenalkoxy, alkoxycarbonyl or alkylaminocarbonyl. The invention also relates to a method and intermediate product for the production of said compound in addition to the use thereof for combating undesirable plants