6-fluorospiro[2-benzofuran-3,4'-piperidine]-1-one

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a suspension of 5-fluoro-3H-spiro[2-benzofuran-1,4′-piperidin]-3-one (420 mg, 1.9 mmol) in tetrahydrofuran (4.2 ml) was added dropwise a 1M borane solution in tetrahydrofuran (3.8 ml, 3.8 mmol) at 0° C. The mixture was refluxed overnight and then cooled to 0° C. HCl 5 N (2 ml) was added dropwise. The mixture was refluxed for 5 hours, cooled to 0° C., diluted with water and basified with NaOH 5 N (pH 10). The mixture was extracted 3 times with ethyl acetate. The combined extracts were dried over Na2SO4, filtered and concentrated in vacuo. The residue was stirred with ether and filtrated. The filtrate was concentrated in vacuo to provide 0.22 g (55%) of 5-fluoro-3H-spiro[2-benzofuran-1,4′-piperidine] as a light yellow oil. The mixture was refluxed overnight The mixture was refluxed for 5 hours cooled to 0° C. The mixture was extracted 3 times with ethyl acetate The combined extracts were dried over Na2SO4 filtered concentrated in vacuo filtrated The filtrate was concentrated in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1′-Benzyl-5-fluoro-3H-spiro[2-benzofuran-1,4′-piperidin]-3-one (0.622 g, 2 mmol) was suspended in ethanol (6 ml). The mixture was acidified with a few drops of HCl 37%. Pd/C 10% (65 mg, 0.06 mmol) was added. The mixture was refluxed under an hydrogen atmosphere for 1 hour then cooled to room temperature, purged with argon and diluted with dichloromethane. The catalyst was filtered and the filtrate was concentrated in vacuo. The white solid was dissolved in water (20 ml). The solution was basified with a 2M Na2CO3 solution and extracted 3 times with dichloromethane. The combined extracts were dried over Na2SO4, filtered and concentrated in vacuo to yield 0.42 g (96%) 5-fluoro-3H-spiro[2-benzofuran-1,4′-piperidin]-3-one as a white solid. MS m/e: 222 (M+H+). The mixture was refluxed under an hydrogen atmosphere for 1 hour purged with argon diluted with dichloromethane The catalyst was filtered the filtrate was concentrated in vacuo The white solid was dissolved in water (20 ml) extracted 3 times with dichloromethane The combined extracts were dried over Na2SO4 filtered concentrated in vacuo