Reaction Steps
To (R)-tert-butyl 2-(tert-butyldimethylsilyloxy)ethyl(4-(5-(4-phenyl-5-(trifluoromethyl)thiophen-2-yl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)carbamate INT-63 (0.108 g, 0.16 mmol) dissolved in DCM (1.5 mL) was added 2N HCl in ether (1.45 mL, 2.9 mmol). The solution was stirred at room temperature for 12 h. The solvent was removed under a stream of nitrogen and the product dried under vacuum to afford 0.052 g (65%) of (R)-2-(4-(5-(4-phenyl-5-(trifluoromethyl)thiophen-2-yl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-ylamino) ethanol 67 as the HCl salt. LCMS-ESI (m/z): calcd for C24H20F3N3O2S: 471.5; found 472.1 [M+H]+, tR=7.43 min (Method 2). 1H NMR (400 MHz, CDCl3) δ 9.62 (s, 1H), 8.19 (d, J=7.6, 1H), 8.03 (d, J=7.5, 1H), 7.87 (t, J=1.5, 1H), 7.53-7.40 (m, 6H), 4.86 (d, J=4.8, 1H), 3.88 (s, 2H), 3.74-3.50 (m, 1H), 3.41 (ddd, J=13.3, 9.4, 4.4, 1H), 3.06 (m, 1H), 2.98 (m, 1H), 2.67-2.42 (m, 2H). 13C NMR (100 MHz, DMSO) δ 169.22, 168.07, 145.68, 144.75, 139.39, 135.43, 132.42, 129.42, 129.37, 129.25, 128.69, 128.27, 127.62, 126.41, 123.16, 122.37, 120.47, 61.10, 56.63, 46.54, 31.66, 27.80.
