A process for manufacturing 5,6-disubstituted-3-pyridylmethyl ammonium bromides (I), wherein Q is a tertiary aliphatic or cyclic, saturated, partially unsaturated or aromatic amine; Z is hydrogen or halogen; Z1 is hydrogen, halogen, cyano or nitro; Y and Y1 are each independently OR1, NR1R2, or when taken together YY1 is —O—, —S— or NR3—; R1 and R2 are each independently hydrogen, C1-C4 alkyl optionally substituted with C1-C4 alkoxy or phenyl optionally substituted with one to three C1-C4 alkyl groups, C1-C4 alkoxy groups or halogen atoms, or phenyl optionally substituted with one to three C1-C4 alkyl groups, C1-C4 alkoxy groups or halogen atoms; R3 is hydrogen or C1-C4 alkyl; comprises the steps of (i) reacting a compound of formula (II), wherein the symbols have the meaning given in formula (I), with bromine in the presence of a radical initiator in a solvent mixture comprising an aqueous phase and an organic phase, where the organic phase comprises a solvent selected from 1,2-dichloroethane, chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene and tetrachloromethane, and where the pH-value of the aqueous phase is from 3 to