3-(1-Isopropyl-piperidin-4-ylmethoxy)-benzoic acid methyl ester. A mixture of 3-(piperidin-4-ylmethoxy)-benzoic acid methyl ester (6.82 g, 27.4 mmol), acetone (40 mL), acetic acid (1.6 mL, 27.4 mmol), and NaB(OAc)3H (18.4 g, 86.8 mmol) in THF (110 mL) was stirred for 4.5 h. The mixture was diluted with CH2Cl2, washed with 1 N NaOH and brine, dried (Na2CO3), and concentrated to give the crude product. Chromatographic purification (EtOAc/hexanes) yielded the desired product as a pale yellow oil (6.43 g, 81%). MS: exact mass calcd for C17H25NO3, 291.2; m/z found, 292.5 [M+H]+. 1H NMR (MeOH-d4): 7.55 (dd, J=1.0, 7.7, 1H), 7.49 (m, 1H), 7.33 (m, 1H), 7.12 (m, 1H), 3.87 (s, 3H), 3.82 (d, J=6.2, 2H), 2.91 (d, J=11.6, 2H), 2.69 (heptet, J=6.6, 1H), 2.18 (m, 2H), 1.83 (d, J=13.2, 2H), 1.77 (m, 1H), 1.40 (m, 2H), 1.05 (d, J=6.6, 6H).
