Reaction Steps
Prepared using General Procedure 7. To 2-hydroxyacetic acid (7 mg, 0.08 mmol) in DMF (2 mL) was added HOBt (12 mg, 0.09 mmol) and EDC (17 mg, 0.09 mmol). The reaction mixture was stirred at room temperature for 0.5 h until the acid was fully activated. (R)-5-(3-(1-amino-2,3-dihydro-1H-inden-4-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile 49 (25.0 mg, 0.07 mmol) was added in one portion and the reaction was stirred at room temperature for 12 h. The reaction mixture was diluted with EA and washed with NaHCO3. The combined aqueous layers were back-extracted with EA. The resulting combined organic layers were dried over Na2SO4 and concentrated to a brown oil which was purified by chromatography (MeOH/DCM) to provide 14 mg (48%) of (R)—N-(4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)-2-hydroxy acetamide 65 as a white solid. LCMS-ESI (m/z) calculated for C22H22N4O4: 418.5; found 419.0 [M+H]+, tR=2.47 min. 1H NMR (400 MHz, CDCl3) δ 8.39 (d, J=2.2 Hz, 1H), 8.32 (dd, J=8.9, 2.2 Hz, 1H), 8.08 (d, J=7.6 Hz, 1H), 7.45 (d, J=7.5 Hz, 1H), 7.38 (t, J=7.6 Hz, 1H), 7.12 (d, J=9.0 Hz, 1H), 6.76 (d, J=8.6 Hz, 1H), 5.61 (d, J=8.1 Hz, 1H), 4.80 (dt, J=12.2, 6.1 Hz, 1H), 4.20 (s, 2H), 3.49 (m, 1H), 3.23 (dd, J=17.1, 8.5 Hz, 1H), 2.80-2.60 (m, 1H), 1.93 (dd, J=13.0, 8.4 Hz, 1H), 1.47 (t, J=5.6 Hz, 6H). 13C NMR (101 MHz, CDCl3) δ 173.11, 171.21, 168.78, 162.78, 144.48, 143.21, 134.11, 133.88, 128.56, 127.42, 126.83, 123.29, 116.76, 115.26, 113.55, 103.90, 72.77, 62.25, 54.00, 33.52, 31.71, 21.72.
