Acetic Acid → Benzyl 1-cyclopentylpiperidine-3-carboxylate

HRID 253098Notes

Reaction equation

HRID 253098 reaction equation
[NH:1]1[CH2:6][CH2:5][CH2:4][CH:3]([C:7]([O:9][CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[O:8])[CH2:2]1.[C:17]1(=O)[CH2:21][CH2:20][CH2:19][CH2:18]1.CC(O)=O.[BH-](OC(C)=O)(OC(C)=O)OC(C)=O.[Na+]>ClCCCl>[CH:17]1([N:1]2[CH2:6][CH2:5][CH2:4][CH:3]([C:7]([O:9][CH2:10][C:11]3[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=3)=[O:8])[CH2:2]2)[CH2:21][CH2:20][CH2:19][CH2:18]1

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 8452CyclopentanoneHCID 5049666Sodium triacetoxyborohydrideHCID 13419237Benzyl piperidine-3-carboxylate

Product 1

HCID 66844606Benzyl 1-cyclopentylpiperidine-3-carboxylate

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

The crude amine from the above step was dissolved in 1,2-dichloroethane (15 mL) and cyclopentanone (1.0 mL) was added via syringe. The reaction was allowed to stir for 5 min before the addition of HOAc (0.6 mL) and NaBH(OAc)3 (2.3 g, 10.9 mmol) in one portion. The reaction was allowed to stir for 48 h and then quenched with Na2CO3 (10%, 20 mL) and the reaction was allowed to stir for 1 h before being extracted with DCM (3×50 mL). The combined organics were washed with brine (sat, 200 mL), dried with sodium sulfate, filtered, concentrated to provide 1.3 g of crude oil that was purified by a 120 g Isco normal phase column (100% EtOAc) to give benzyl 1-cyclopentylpiperidine-3-carboxylate as a colorless oil. MS m/z: 288 (M+1).

Workup

  1. customquenched with Na2CO3 (10%, 20 mL)
  2. stirringto stir for 1 h
  3. extractionbefore being extracted with DCM (3×50 mL)
  4. washThe combined organics were washed with brine (sat, 200 mL)
  5. dry with materialdried with sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customto provide 1.3 g of crude oil that
  9. customwas purified by a 120 g Isco normal phase column (100% EtOAc)

Sources & evidence

ORD record
ord-3c93f273449f43acb84c08a258680b98
Source dataset
uspto-grants-2011_01
Patent number
US07872009B2

Reaction notes

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