Fig. 2

Synthesis of alkyne precursor 5, non-radioactive mBPET-1, and mBRef-1. i) Br₂, Et₂O, 2 h, rt., 80%; ii) acetyl chloride, Et₃N, THF, 5 min, 0 °C; iii) phenylacetylene, 5 mol% Pd (OAc)₂, 7.5 mol% P^tBu₃*HBF₄, 5 mol% CuI, diisopropylamine, 2 h, 60 °C; iv) KOH/aq. methanol, 2 h, 75 °C, 96%; v) p-HCHO, Et₃N, MgCl₂, acetonitrile, reflux, 19 h, 65%; vi) MeI, K₂CO₃, acetone, 18 h, 55 °C, quant.; vii) K₂CO₃, THF, reflux, 4 h, 14%; viii) NaBH₃CN, acetic acid (cat.), methanol, 18 h, rt., 55%; ix) NaN₃, DMF, 24 h, rt.; x) 10 mol% CuI, sodium ascorbate, diisopropylethylamine, H₂O/MeCN/DMF, 2 h, rt., 25%; xi) NaBH₃CN, acetic acid (cat.), methanol, 48 h, rt., 58%