Reaction Steps
Palladium on carbon (10%, 14 mg) was added to 25f (68.0 mg, 0.12 mmol) in anhydrous THF (800 μL) and the solution was placed under an atmosphere of H2. After 12 hours, the solution was filtered through SiO2 (1:1 CH2Cl2:Acetone) and the eluent was concentrated to afford a yellow solid, which was used without further purification (52.0 mg, 99%). EDCI (18.5 mg, 0.096 mmol) and 3′,6-dimethoxybiphenyl-3-carboxylic acid (19.9 mg, 0.077 mmol) were added to the amine (17.5 mg, 0.039 mmol) in 30% pyridine/CH2Cl2 (1.10 mL). After 12 hours, the solvent was concentrated and the residue purified via column chromatography (SiO2, 40:1 CH2Cl2:Acetone) to afford a colorless solid, which was used without further purification (14.0 mg, 52%). Triethylamine (150 μL) was added to the carbonate (14.0 mg, 0.020 mmol) in MeOH (1.5 mL) and CH2Cl2 (1.5 mL). After 48 hours, the solvent was concentrated and the residue purified via column chromatography (SiO2, 40:1 CH2Cl2:Acetone) to afford 26f as a colorless amorphous solid (5.20 mg, 39%, 20% over 3 steps): 1H NMR (CD2Cl2, 500 MHz) 8.85 (s, 1H), 8.65 (s, 1H), 7.92 (d, J=2.4 Hz, 1H), 7.90 (d, J=2.4 Hz, 1H), 7.86 (d, J=2.4 Hz, 1H), 7.57-7.43 (m, 3H), 7.36-7.33 (m, 4H), 7.11-7.06 (m, 3H), 6.92 (d, J=0.8 Hz, 1H), 5.52 (d, J=2.4 Hz, 1H), 4.08 (q, J=7.2, Hz, 1H), 3.89 (s, 3H), 3.83 (s, 3H), 3.74 (dd, J=9.0, 3.5 Hz, 1H), 3.50 (s, 3H), 3.23 (d, J=9.0 Hz, 1H), 2.12 (s, 1H), 2.00 (s, 1H), 1.33 (s, 3H), 1.04 (s, 3H); 13C NMR (CD2Cl2, 125 MHz) δ 164.5, 159.0 (2C), 158.6, 158.1, 154.4, 147.2, 138.0 (2C), 130.7, 130.1, 129.7, 129.1, 128.7, 128.3, 127.4, 127.2, 127.0, 127.0, 125.2, 122.6, 121.6, 121.1, 118.6, 114.5, 113.8, 112.1, 111.3, 110.2, 97.5, 70.1 (2C), 67.4, 60.8, 55.0, 54.5, 21.9, 21.6; IR (film) νmax 3402, 2932, 2359, 2341, 1713, 1603, 1524, 1500, 1367, 1267, 1086, 1040, 964, 750 cm−1; HRMS (ESI+) m/z: [M+H]+ calcd for C38H37NO10, 668.2496. found, 668.2485.
