4 2 aminoethyl aniline

Lead(II) bromide (PbBr₂, Sigma-Aldrich, 99.9% purity), methylamine (CH₃NH₂·H₂O, Sigma-Aldrich, 33 wt % in ethanol), 4-aminobenzylamine (C₇H₁₀N₂, Sigma-Aldrich, 99% purity) 4-(2-aminoethyl)aniline (C₈H₁₂N₂, Sigma-Aldrich, 97% purity), nitrosobenzene (C₆H₅NO, Sigma-Aldrich, 97% purity), 9-fluorenylmethoxycarbonyl chloride (C₁₅H₁₁ClO₂, Fmoc-Cl, Carbolution, 98% purity), piperidine (C₅H₁₁N, Sigma-Aldrich, 99.5% purity), hydrobromic acid (48 wt % in H₂O, Sigma-Aldrich), 4-(phenylazo)phenol (C₁₂H₁₀N₂O, Sigma-Aldrich, 98% purity), 1,4-dibromobutane (C₄H₈Br₂, Sigma-Aldrich, 99% purity), 1,12-dibromododecane (C₁₂H₂₄Br₂, Sigma-Aldrich, 98% purity), phthalimide potassium salt (C₈H₄KNO₂, abcr, 98% purity) and hydrazine monohydrate (N₂H₂·H₂O, acros organics, 99% purity) were used without further purification.

Dopamine 2, L-tyrosine 4, L-DOPA 5, tyramine 7, sodium ascorbate 8, 3-Cl-L-tyrosine 12, 3-I-L-tyrosine 13, 3-phenyl-1-propylamine 14, sodium pyruvate 15, 3-NH₂-L-tyrosine 32, 3-NO₂-L-tyrosine 33, octopamine 34, synephrine 35, 4-(2-aminoethyl)aniline 36, 4-F-L-phenylalanine 37, 4-Cl-L-phenylalanine 38, 4-Br-L-phenylalanine 39, 4-OMe-L-phenylalanine 40, 4-NH₂-L-phenylalanine 41, 4-NO₂-L-phenylalanine 42, PLP, CuSO₄ · 5H₂O and kanamycin were purchased from Sigma-Aldrich (Germany). Meta-L-tyrosine 9, meta-tyramine 10, 3-F-L-tyrosine 11, phenylacetaldehyde 47, 2-bromophenylacetaldyhyde 50 and IPTG was purchased from Alfa Aesar (Thermo Fisher Scientific, USA). All chemicals were purchased in the highest purity available. Thin layer chromatography was performed using plates with a silica gel matrix on an aluminium support. Ultraviolet light (254 nm) and ninhydrin stain was used to visualise the plates.