Cesium carbonate → 2-[6-(Benzothiazol-2-yloxy)-benzofuran-3-yl]-ethanol

To a solution of 3-(2-hydroxy-ethyl)-benzofuran-6-ol (0.42 g, 2.4 mmol) in MeCN (10 mL) was added Cs2CO3 (0.77 g, 2.4 mmol) and 2-chlorobenzthiazole (0.29 mL, 2.4 mmol) and the reaction mixture was stirred (rt, 15 h) and then heated (60° C., 2 h). The reaction mixture was cooled (rt) and partitioned with EtOAc and brine (50 mL each). The aqueous layer was extracted with EtOAc (50 mL). The combined organic layers were washed with brine (50 mL), dried, filtered and concentrated in vacuo. The resulting residue was purified by silica gel flash chromatography using EtOAc:hexane (0-100%) to provide the title compound as an amber oil (0.37 g, 50%). MS (ESI): mass calcd. for C17H13NO3S, 311.4; m/z found, 312.1 [M+H]+. 1H NMR (500 MHz, CDCl3): 7.73 (d, J=8.0, 1H), 7.67 (d, J=8.0, 1H), 6.61 (d, J=8.5, 1H), 7.58 (br s, 1H), 7.53 (d, J=2.0, 1H), 7.41-7.37 (m, 1H), 7.29-7.26 (m, 2H), 3.97-3.93 (m, 2H), 3.96 (t, J=6.5, 2H), the hydroxyl proton was not detected.

1. temperatureheated (60° C., 2 h)
2. temperatureThe reaction mixture was cooled (rt)
3. custompartitioned with EtOAc and brine (50 mL each)
4. extractionThe aqueous layer was extracted with EtOAc (50 mL)
5. washThe combined organic layers were washed with brine (50 mL)
6. customdried
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe resulting residue was purified by silica gel flash chromatography

ORD record

ord-20c1176cd7064124aa4ec3d2070426fe

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08399465B2