Benzyl Alcohol → N-(tert-butoxycarbonyl)-3-cyclopentyl-L-alanine benzyl ester

HRID 850889Notes

Reaction equation

HRID 850889 reaction equation
[C:1]([O:5][C:6]([NH:8][C@H:9]([C:16]([OH:18])=[O:17])[CH2:10][CH:11]1[CH2:15][CH2:14][CH2:13][CH2:12]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[CH2:19](O)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1.ON1C2C=CC=CC=2N=N1.Cl.CN(C)CCCN=C=NCC>CN(C)C1C=CN=CC=1.ClCCl>[CH2:19]([O:17][C:16](=[O:18])[C@H:9]([CH2:10][CH:11]1[CH2:12][CH2:13][CH2:14][CH2:15]1)[NH:8][C:6]([O:5][C:1]([CH3:4])([CH3:2])[CH3:3])=[O:7])[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1

Participants

7

Reactant 4

HCID 244Benzyl AlcoholHCID 757711-HydroxybenzotriazoleHCID 27239391,3-Propanediamine, N'-(ethylcarbonimidoyl)-N,N-dimethyl-, monohydrochlorideHCID 40418614N-(tert-Butoxycarbonyl)-3-cyclopentyl-L-alanine

Product 1

HCID 54072905N-(tert-butoxycarbonyl)-3-cyclopentyl-L-alanine benzyl esterYield 95.5%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalyst2×HCID 6344DichloromethaneSolvent

Procedure

A mixture of 1.2 g (4.67 mmol) of N-(tert-butoxycarbonyl)-3-cyclopentyl-L-alanine, 540 mg (5 mmol) of benzyl alcohol, 675 mg (5 mmol) of 1-hydroxybenzotriazole, 1.152 g (6 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.031 g (0.25 mmol) of 4-dimethylaminopyridine was stirred in 20 ml of dichloromethane for 1 hour and then a further 610 mg (5 mmol) of 4-dimethylaminopyridine were added. After 4 hours the solution was extracted with 2M hydrochloric acid and saturated sodium bicarbonate solution, dried over anhydrous magnesium sulphate and evaporated. The oil obtained was chromatographed on silica gel using ethyl acetate/ petrol (1:6) for the elution to give 1.55 g of N-(tert-butoxycarbonyl)-3-cyclopentyl-L-alanine benzyl ester as a colourless oil; MS: m/e 348 [M+H].

Workup

  1. extractionAfter 4 hours the solution was extracted with 2M hydrochloric acid and saturated sodium bicarbonate solution
  2. dry with materialdried over anhydrous magnesium sulphate
  3. customevaporated
  4. customThe oil obtained
  5. customwas chromatographed on silica gel
  6. washfor the elution

Sources & evidence

ORD record
ord-e0c10ece33f44c8e8fd3e8180845a902
Source dataset
uspto-grants-2000_01
Patent number
US06018020

Reaction notes

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