Cyclopentanone → (R)-Methyl 2-(cyclopentylamino)butanoate

HRID 44801Notes

Reaction equation

HRID 44801 reaction equation
[NH2:1][C@H:2]([CH2:7][CH3:8])[C:3]([O:5][CH3:6])=[O:4].[C:9]1(=O)[CH2:13][CH2:12][CH2:11][CH2:10]1.C([O-])(=O)C.[Na+].C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].C(=O)(O)[O-].[Na+]>C(Cl)Cl>[CH:9]1([NH:1][C@H:2]([CH2:7][CH3:8])[C:3]([O:5][CH3:6])=[O:4])[CH2:13][CH2:12][CH2:11][CH2:10]1

Participants

7

Reactant 5

HCID 8452CyclopentanoneHCID 516892Sodium BicarbonateHCID 517045Sodium AcetateHCID 5049666Sodium triacetoxyborohydrideHCID 13283514methyl (2R)-2-aminobutanoate

Product 1

HCID 57358664(R)-Methyl 2-(cyclopentylamino)butanoateYield 95%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Compound II (7.4 g) and cyclopentanone (4.1 g, 49 mmol) were dissolved in 80 mL DCM. After the addition of sodium acetate (4.0 g, 4 mmol) and sodium triacetoxyborohydride (15.0 g, 71 mmol) at 0° C., the mixture was stirred for 12 hr at rt and then 50 mL saturated sodium bicarbonate solution were added. The aqueous phase was extracted with dichloromethane. The combined organic phases were washed with water, dried over MgSO4 and evaporated down to give (R)-methyl 2-(cyclopentylamino)butanoate as a light yellow oil (compound III, 8.6 g, 95% yield).

Workup

  1. extractionThe aqueous phase was extracted with dichloromethane
  2. washThe combined organic phases were washed with water
  3. dry with materialdried over MgSO4
  4. customevaporated down

Sources & evidence

ORD record
ord-8cd71612474a455683a12ee501691e45
Source dataset
uspto-grants-2013_09
Patent number
US08541418B2

Reaction notes

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