Fig. 2

Synthesis of \({\bf{MAG}}_{{\bf{2P}}}^{{\bf{slow}}}\) and \({\bf{MAG}}_{{\bf{2P}}_ - {\bf{F}}}^{{\bf{slow}}}\). Reagents and conditions: (a) 5.5 M HCl, NaNO₂; (b) (i) 1, 0.86 M NaOAc; (ii) 1 M NaOH; (iii) 5.5 M HCl (38%, over the two steps, for 5a, 47% for 5b); (c) tert-butyl (2-aminoethyl)carbamate, N-ethyl-N′-(3-dimethyldiaminopropyl)-carbodiimide HCl (EDCI), 1-hydroxybenzotriazole hydrate (HOBt), diisopropylethylamine (DIPEA), THF; (d) 37% HCl, MeOH; (e) 2, EDCI, HOBt, DIPEA, THF (47%, over the three steps, for 6a, 49% for 6b); (f) (i) 3, ClCOCOCl, CH₂Cl₂, DMF; (ii) DIPEA, THF (86% for 7a, 84% for 7b); (g) trifluoroacetic acid (TFA), CH₂Cl₂ (80% for \({\bf{MAG}}_{{\bf{2P}}_ - {\bf{F}}}^{{\bf{slow}}}\), quantitative yield for \({\bf{MAG}}_{{\bf{2P}}_ - {\bf{F}}}^{{\bf{slow}}}\))