反应详情

A solution of methyl 2-tert-butoxy-2-(4-(4-fluorophenyl)-2-isopropyl-8,8-dimethyl-6-(2,2,2-trifluoroacetyl)-5,6,7,8-tetrahydro-1,6-naphthyridin-3-yl)acetate (intermediate 4) (0.483 g, 0.897 mmol) and 1N NaOH (4.48 ml) in MeOH (10 mL) was stirred at room temperature overnight (15 h) and then 8 h at reflux. After cooling the product was purified by preparative-HPLC (CH3CN/H2O, 10 mmol NH4OAc) to provide 2-tert-butoxy-2-(4-(4-fluorophenyl)-2-isopropyl-8,8-dimethyl-5,6,7,8-tetrahydro-1,6-naphthyridin-3-yl)acetic acid (0.126 g, 31% yield). 1H NMR (500 MHz, DMSO-d6) δ ppm 7.37 (2H, d, J=6.7 Hz), 7.31 (2H, d, J=6.7 Hz), 4.67 (1H, s), 3.59 (1H, d, J=16.2 Hz), 3.51-3.57 (1H, m), 3.33 (2H, br. s.), 3.10 (1H, d, J=16.2 Hz), 2.72-2.82 (2H, m), 1.28 (6H, s), 1.19 (3H, d, J=6.4 Hz), 1.07 (3H, d, J=6.7 Hz), 0.87 (9H, s). LCMS (M+H) calcd for C25H34FN2O3: 429.26. found: 429.3.

1. temperature8 h at reflux
2. temperatureAfter cooling the product