Hydrochloric Acid → 3-(4-Bromophenyl)piperidine

To an ice-cooled solution of 3-(4-bromo-phenyl)-piperidin-2-one (37.97 g, 149 mmol) in tetrahydrofuran (250 ml) was added borane-tetrahydrofuran complex (335 ml, 1.0 M solution in THF, 335 mmol). The solution was stirred overnight at room temperature, and then refluxed 1.5 hr after addition of 10% aqueous hydrochloric acid. Solvents was removed in vacuo, and the residue was partitioned between dichloromethane and 1N sodium hydroxide. The aqueous layer was extracted with dichlorometane. The combined organic layer was washed with water and brine, dried over sodium sulfate, and concentrated in vacuo. The residue was dissolved in water (100 mL) and concentrated hydrochloric acid (100 mL) and refluxed for 3 hr. Sodium hydroxide was added to the solution and the resulting solution was extracted with dichlorometane. The organic layer was washed with water and brine, dried over sodium sulfate Concentration in vacuo afforded 3-(4-bromo-phenyl)-piperidine (32 18 g, 90%).

1. temperaturerefluxed 1.5 hr
2. customSolvents was removed in vacuo
3. customthe residue was partitioned between dichloromethane and 1N sodium hydroxide
4. extractionThe aqueous layer was extracted with dichlorometane
5. washThe combined organic layer was washed with water and brine
6. dry with materialdried over sodium sulfate
7. concentrationconcentrated in vacuo
8. dissolutionThe residue was dissolved in water (100 mL)
9. temperatureconcentrated hydrochloric acid (100 mL) and refluxed for 3 hr
10. additionSodium hydroxide was added to the solution
11. extractionthe resulting solution was extracted with dichlorometane
12. washThe organic layer was washed with water and brine
13. dry with materialdried over sodium sulfate Concentration in vacuo

ORD record

ord-6d4e95c7133d42b48eeb2ffe5e987cab

Source dataset

uspto-grants-2009_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07504411B2