Acetic Anhydride → 2-[6-Acetyl-4-(4-fluorophenyl)-2-isopropyl-8,8-dimethyl-5,7-dihydro-1,6-naphthyridin-3-yl]-2-tert-butoxy-acetic acid

Participants

Reaction Steps

To a stirred solution of 2-tert-butoxy-2-(4-(4-fluorophenyl)-2-isopropyl-8,8-dimethyl-5,6,7,8-tetrahydro-1,6-naphthyridin-3-yl)acetic acid (example 1)(0.012 g, 0.028 mmol) and Et3N (0.139 ml, 1 mmol) in CH2Cl2 (5 mL) was added Ac2O (0.026 ml, 0.280 mmol) at room temperature. After 3 h, the reaction mixture concentrated and purified by preparative-HPLC (MeCN/H2O/NH4OAc) to afford 2-(6-acetyl-4-(4-fluorophenyl)-2-isopropyl-8,8-dimethyl-5,6,7,8-tetrahydro-1,6-naphthyridin-3-yl)-2-tert-butoxyacetic acid (0.011 g, 76% yield) as white powder and mixture of rotomers. 1H NMR (500 MHz, CDCl3) δ ppm 7.41-7.54 (1H, m), 7.11-7.23 (3H, m), 4.91 (1H, br. s.), 4.49 (0.7H, d, J=17.4 Hz), 4.28 (0.3H, d, J=16.5Hz), 4.08 (0.7H, d, J=17.7 Hz), 3.93 (0.3H, d, J=16.8 Hz), 3.39-3.52 (2H, m), 3.15-3.27 (1H, m), 2.15 (2H, s), 1.95 (1H, s), 1.27-1.39 (9H, m), 1.15 (3H, d, J=5.5Hz), 0.90 (3H, s), 1.00 (6H, s). LCMS (M+H) calcd for C27H36FN2O4: 471.27. found: 471.3.

Provenance & Evidence