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

HRID 1377884Notes

Reaction equation

HRID 1377884 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 filtrate was concentrated, and the residue was purified by silica gel column chromatography, using 10% acetone in hexane as eluant. Ester (23) (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 filtrate was concentrated
  7. customthe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-54e13c283e7e4d7792d94ee3287ba834
Source dataset
uspto-grants-1997_09
Patent number
US05665774

Reaction notes

Loading…