23-F (7.0 mg, 0.019 mmol) and triethylamine (8 μL, 0.0573 mmol) were dissolved in methylene chloride (0.25 mL). Benzoyl chloride (2.8 μL, 0.0239 mmol) was added and the reaction was allowed to stir at room temperature. DMF (0.25 mL) was added and allowed to stir overnight. The reaction was chromatographed on a 21 mm Luna C18 column using a 10–90% acetonitrile in water gradient with 0.05% trifluoroacetic acid at 12.5 mL per minute over a 30 minute period. The major fraction was lyophilized to give a white powder (2.0 mg, 29%). 1H NMR (500 MHz, CD3OD): δ 7.91 (d, J=8.7 hz, 2H), 7.81 (d, J=8.9 Hz, 2H), 7.52 (d, J=8.8 Hz, 2H), 7.43 (m, 3H), 6.97 (s, 1H), 6.69 (br s, 1H), 3.47 (t, J=7.0 Hz, 2H), 2.91 (t, J=7.0 Hz, 2H); LCMS found for C18H17N2O4S (M+H)+: m/z=357.
