Methanol → Tert-butyl 2-(cyclopentylamino)acetate

HRID 330465Notes

Reaction equation

HRID 330465 reaction equation
C([BH3-])#N.[Na+].[C:5]1(=O)[CH2:9][CH2:8][CH2:7][CH2:6]1.Cl.[C:12]([O:16][C:17](=[O:20])[CH2:18][NH2:19])([CH3:15])([CH3:14])[CH3:13].CO>OP(O)(O)=O.O>[C:12]([O:16][C:17](=[O:20])[CH2:18][NH:19][CH:5]1[CH2:9][CH2:8][CH2:7][CH2:6]1)([CH3:15])([CH3:14])[CH3:13]

Participants

7

Reactant 4

HCID 887MethanolHCID 8452CyclopentanoneHCID 2725036Glycine tert-butyl ester hydrochlorideHCID 5003444Sodium cyanoborohydride

Product 1

HCID 13298943Tert-butyl 2-(cyclopentylamino)acetateYield 90.4%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 1004Phosphoric AcidSolvent

Procedure

Sodium cyanoborohydride(1.9 g) was added portionwise to a stirred mixture of cyclopentanone(2.1 g), glycine tert-butyl ester hydrochloride(5.0 g), water(12 ml) and methanol(25 ml) during 15 min at water-bath temperature. The resulting mixture was stirred for 4 hr, diluted with 20% H3PO4 (40 ml) and water(20 ml), and extracted with ether(80 ml). The aqueous layer was made alkaline(pH 10) with 20% NaOH and extracted with CHCl3 (50 ml). The extract was dried(Na2SO4) and concentrated in vacuo to give an oily residue, which was purified by silica gel column chromatography(ethyl acetate:hexane=3:1) to yield N-cyclopentylglycine tert-butyl ester(4.5 g) as a pale yellow oil.

Workup

  1. extractionextracted with ether(80 ml)
  2. extractionextracted with CHCl3 (50 ml)
  3. concentrationconcentrated in vacuo
  4. customto give an oily residue, which
  5. customwas purified by silica gel column chromatography(ethyl acetate:hexane=3:1)

Sources & evidence

ORD record
ord-1692ad828a2244acb9e1d559b12acc7c
Source dataset
uspto-grants-1990_01
Patent number
US04897379

Reaction notes

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