Benzyl Alcohol → (S)-N-9-Fluorenylmethoxycarbonyl-N-ethylalanine benzylester

HRID 439822Notes

Reaction equation

HRID 439822 reaction equation
[C:1]([N:18]([CH2:24][CH3:25])[C@H:19]([C:21]([OH:23])=[O:22])[CH3:20])([O:3][CH2:4][CH:5]1[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[C:11]2[C:6]1=[CH:7][CH:8]=[CH:9][CH:10]=2)=[O:2].C(Cl)(=O)C(Cl)=O.[CH2:32](O)[C:33]1[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=1>ClCCl.CN(C)C=O.[Ag]C#N>[CH2:32]([O:22][C:21](=[O:23])[C@H:19]([CH3:20])[N:18]([C:1]([O:3][CH2:4][CH:5]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:11]=2[C:12]2[C:17]1=[CH:16][CH:15]=[CH:14][CH:13]=2)=[O:2])[CH2:24][CH3:25])[C:33]1[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=1

Participants

7

Reactant 3

HCID 244Benzyl AlcoholHCID 65578Oxalyl chlorideHCID 18650330N-Fmoc-N-ethyl-L-alanine

Product 1

HCID 53671911(S)-N-9-Fluorenylmethoxycarbonyl-N-ethylalanine benzylesterYield 377.2%

Reagents, catalysts & solvents 3

HCID 6228DimethylformamideCatalystHCID 178509332CID 101611454CatalystHCID 6344DichloromethaneSolvent

Conditions

Temperature
80 °C

Procedure

A suspension of 848 mg (2.5 mmol) of (S)-N-Fmoc-N-ethylalanine in 10 mL Of dichloromethane was treated with 436 μL (5.0 mmol) of oxalyl chloride followed by a catalytic amount (1 drop) of dimethylformamide. The mixture was stirred for one hour, then concentrated in vacuo. The yellow, oily residue was treated with 10 mL of toluene followed by 517 mg (0.5 mmol) of benzyl alcohol and 669 mg (5.0 mmol) of silver cyanide. The mixture was heated in an 80° C. oil bath with vigorous stirring for 20 minutes, then cooled and filtered through a pad of diatomaceous earth. The liltrate was concentrated, and the residue was purified by silica gel column chromatography, using 10% acetone in hexane as eluant. Ester (142) (810 mg) was obtained as a colorless oil; TLC: Rf =0.28, 15% acetone/hexane; 1H NMR (300 MHz) consistent with structure.

Workup

  1. concentrationconcentrated in vacuo
  2. additionThe yellow, oily residue was treated with 10 mL of toluene
  3. stirringwith vigorous stirring for 20 minutes
  4. temperaturecooled
  5. filtrationfiltered through a pad of diatomaceous earth
  6. concentrationThe liltrate was concentrated
  7. customthe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-11f4522220c74cddabd0b97629c4508d
Source dataset
uspto-grants-1996_05
Patent number
US05516797

Reaction notes

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