The invention relates to a method for producing a radiofluorinated compound which has an aromatic or heteroaromatic ring which carries [18F] fluorine as the first substituent, a bonding unit which can bond to a peptide or a peptide mimetic, and a spacer group which connects the aromatic or heteroaromatic ring to the bonding unit, the bonding unit carrying at least one second substituent selected from the group consisting of -OH, -CONH and -COOH, the bonding unit being connected to the spacer group via a bond A1, and the spacer group being connected to the aromatic or heteroaromatic ring via a bond A2. According to the invention, the method comprises the following steps: (a) providing a precursor which has the aromatic or heteroaromatic ring which carries a substituent Y, the bonding unit which can bond to the peptide or the peptide mimetic and carries the at least one second substituent, and the spacer group, wherein the substituent Y is selected from the group consisting of -N+(R1R2R3), -NO2, -Cl, -Br, -F or -I, and R1, R2 and R3 are identical to or different from one another and are each unsubstituted or substituted C1-C6 alkyl； and (b) reacting the precursor with an [18F] fluoride anion in the presence of an activation salt to produce the radiofluorinated compound, wherein the substituent Y is replaced by [18F] fluorine and wherein the activation salt has a cation of the general formula N+(R4R5R6R7), where R4, R5, R6 and R7 are identical to or different from one another and are each unsubstituted or substituted C1-C6 alkyl.
