Reaction Steps
Prepared using General Procedures 7 and 8: To a solution of (S)-2-(4-(tert-butyl)benzamido)-3-(4-(5-(4-(heptyloxy)phenyl)-1,2,4-oxadiazol-3-yl)phenyl)propanoic acid, Compound 2(10.0 mg, 0.017 mmol) in anhydrous DMF (1 mL) was added HOBt (3.52 mg, 0.027 mmol) and EDCI (4.88 mg, 0.027 mmol) at room temperature. After 2 h, tert-butyl 2-aminoacetate (3.49 mg, 0.027 mmol) was added and the reaction mixture stirred at room temperature for 2 h. LCMS analysis showed complete conversion to the intermediate. The reaction mixture was partitioned between NaHCO3 aqueous (5 ml) and DCM (1 mL), the organic layer was collected and concentrated by vacuum and then was re-dissolved in 1 mL of DCM and 0.1 mL of TFA. The mixture was heated to 30° C. for 3 h. The final compound was purified by HPLC to afford 9.6 mg (88%) of (S)-2-(2-(4-(tert-butyl)benzamido)-3-(4-(5-(4-(heptyloxy)phenyl)-1,2,4-oxadiazol-3-yl)phenyl)propanamido)acetic acid. LCMS-ESI (m/z) calculated for C37H44N4O6 640.3; no m/z observed, tR=11.51 min (Method 2). 1H NMR (400 MHz, DMSO) δ: 8.60 (d, J=8.4 Hz, 1H), 8.47 (t, J=5.7 Hz, 1H), 8.10 (d, J=8.8 Hz, 2H), 7.96 (d, J=8.2 Hz, 2H), 7.75 (d, J=8.4 Hz, 2H), 7.57 (d, J=8.0 Hz, 2H), 7.45 (d, J=8.4 Hz, 2H), 7.17 (d, J=8.8 Hz, 2H), 4.83 (d, J=8.1 Hz, 1H), 4.09 (t, J=6.4 Hz, 2H), 3.94-3.69 (m, 2H), 3.34 (s, 2H), 3.26 (d, J=13.5 Hz, 1H), 3.15-3.01 (m, 1H), 1.83-1.65 (m, 2H), 1.50-1.15 (m, 16H), 0.87 (t, J=6.7 Hz, 3H). 13C NMR (101 MHz, DMSO) δ: 175.12, 171.58, 171.13, 167.99, 166.02, 162.54, 154.10, 142.44, 131.16, 130.02, 129.89, 127.23, 126.81, 124.91, 124.25, 115.50, 115.36, 67.97, 54.23, 40.10, 37.12, 34.57, 31.19, 30.88, 28.46, 28.37, 25.36, 22.02, 13.93.
