Reaction #11619

Reaction equation

Borane tetrahydrofuran

1-(4-Nitrobenzoyl)piperidine

Borane

→

1-(4-nitro-benzyl)-piperidine

Yield 87.0%

Solvents

tetrahydrofuran

tetrahydrofuran

Conditions

Workup

1. 1
   workup.ADDITIONslowly added dropwise to a 0° C.
2. 2
   Temperatureto warm to room temperature
3. 3
   Temperatureis subsequently heated to 60° C.
4. 4
   TemperatureThe reaction mixture is maintained at 60° C. overnight
5. 5
   Temperatureis cooled to room temperature
6. 6
   Otherquenched with the addition of concentrated HCl (added until gas evolution stops)
7. 7
   OtherThe quenched reaction mixture
8. 8
   Extractionis then extracted with ethyl acetate and water
9. 9
   OtherThe organic layer is separated
10. 10
    Concentrationconcentrated in vacuo, while the aqueous layer
11. 11
    Otheris separated
12. 12
    workup.ADDITIONmade basic with the addition of aqueous 1M NaOH
13. 13
    ExtractionThe basic aqueous layer is then extracted with ethyl acetate
14. 14
    Extractionthe ethyl acetate layer from this extraction
15. 15
    Concentrationis concentrated in vacuo
16. 16
    OtherThe solids isolated from both concentrated ethyl acetate layers

Procedure

1-(4-Nitrobenzoyl)piperidine (0.1125 gms.) is then dissolved in tetrahydrofuran (1 mL) and slowly added dropwise to a 0° C., 1.0 M solution (4 mL) of Borane in tetrahydrofuran. The reaction mixture is maintained at 0° C. for 20 minutes following the completion of the addition to the Borane/tetrahydrofuran solution. The reaction mixture is then allowed to warm to room temperature, and is subsequently heated to 60° C. using an oil bath. The reaction mixture is maintained at 60° C. overnight, then is cooled to room temperature, and quenched with the addition of concentrated HCl (added until gas evolution stops). The quenched reaction mixture is then extracted with ethyl acetate and water. The organic layer is separated, and concentrated in vacuo, while the aqueous layer is separated and made basic with the addition of aqueous 1M NaOH. The basic aqueous layer is then extracted with ethyl acetate and the ethyl acetate layer from this extraction is concentrated in vacuo. The solids isolated from both concentrated ethyl acetate layers are combined to yield 92 mg of 1-(4-nitro-benzyl)-piperidine as a white-yellow solid.

Source