Reaction Steps
To a flask containing (R)-5-(3-(1-hydroxy-2,3-dihydro-1H-inden-4-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile 5 (36 mg, 0.10 mmol) in DCM (1 mL) was added pyridine (24 μL, 0.3 mmol) and acetyl chloride (21 μL, 0.3 mmol). The reaction was stirred at room temperature for 4 days. The crude reaction mixture was washed with saturated sodium bicarbonate, dried over magnesium sulfate, and purified by chromatography (EA/hexane) to give 37 mg (92%) of (R)-4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl acetate 13 as a white solid. LCMS-ESI (m/z) calculated for C23H21N3O4: 403.2; found 426.1 [M+Na]+, tR=4.19 min. 1H NMR (400 MHz, CDCl3) δ 8.37 (d, J=2.1, 1H), 8.27 (dd, J=8.9, 2.2, 1H), 8.10 (dd, J=7.7, 0.9, 1H), 7.53 (d, J=7.4, 1H), 7.35 (t, J=7.7, 1H), 7.06 (d, J=9.0, 1H), 6.21 (dd, J=7.2, 3.7, 1H), 4.73 (hept, J=6.1, 1H), 3.44 (ddd, J=17.5, 8.3, 6.3, 1H), 3.26 (ddd, J=17.6, 8.7, 4.8, 1H), 2.52 (tdd, J=14.9, 7.9, 6.3, 1H), 2.21-2.06 (m, 1H), 2.02 (s, 3H), 1.41 (d, J=6.1, 6H).
