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

Temperature

70 °C

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).

1. filtrationThe reaction mixture was filtered
2. concentrationconcentrated in vacuo
3. customthe resulting residue was partitioned between EtOAc and brine (20 mL each)
4. customThe organic layer was dried
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe resulting residue was purified by silica gel flash chromatography

ORD record

ord-c62e552c64ae41afb74ae3e2f9ead455

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08399465B2