Potassium Carbonate → 1-{2-[6-(Benzothiazol-2-yloxy)-benzofuran-3-yl]-ethyl}-piperidine-4-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a suspension of methanesulfonic acid 2-[6-(benzothiazol-2-yloxy)-benzofuran-3-yl]-ethyl ester (200 mg, 0.5 mmol) and K2CO3 (78 mg, 0.6 mmol) in MeCN (5.2 mL) was added ethyl isonipecotate (0.08 mL, 0.5 mmol) and the reaction mixture was heated (70° C., 48 h). The reaction mixture was filtered, concentrated in vacuo and the resulting residue was partitioned between EtOAc and brine (20 mL each). The organic layer was dried, filtered and concentrated in vacuo. The resulting residue was purified by silica gel flash chromatography using EtOAc:hexane (20-80%) to provide the title compound as a clear oil (108 mg, 47%). MS (ESI): mass calcd. for C25H26N2O4S, 450.6; m/z found, 451.2 [M+H]+. 1H NMR (500 MHz, CDCl3): 7.43 (d, J=8.5, 1H), 7.65 (d, J=8.0, 1H), 7.58 (d, J=8.5, 1H), 7.54 (s, 1H), 7.51 (d, J=1.5, 1H), 7.39-7.36 (m, 1H), 7.27-7.24 (m, 2H), 4.14 (q, J=7.0, 2H), 2.98 (d, J=11.5, 2H), 2.89-2.85 (m, 2H), 2.69-2.66 (m, 2H), 2.34-2.29 (m, 1H), 2.14-2.10 (m, 2H), 1.96-2.94 (m, 2H), 1.85-1.77 (m, 2H), 1.26 (t, J=7.0, 3H).

Provenance & Evidence