L-Valine → N-(4-Nitrophenyl)-L-valine

HRID 648250Notes

Reaction equation

HRID 648250 reaction equation
F[C:2]1[CH:7]=[CH:6][C:5]([N+:8]([O-:10])=[O:9])=[CH:4][CH:3]=1.[NH2:11][C@H:12]([C:16]([OH:18])=[O:17])[CH:13]([CH3:15])[CH3:14].C(=O)(O)[O-].[Na+].C(=O)([O-])[O-].[Na+].[Na+].O(C1C=C(C=CC=1)CBr)C1C=CC=CC=1>C(O)C.O.CN(C)C=O>[N+:8]([C:5]1[CH:6]=[CH:7][C:2]([NH:11][C@H:12]([C:16]([OH:18])=[O:17])[CH:13]([CH3:15])[CH3:14])=[CH:3][CH:4]=1)([O-:10])=[O:9]

Participants

9

Reactant 5

HCID 6287L-ValineHCID 9590p-FluoronitrobenzeneHCID 10340Sodium CarbonateHCID 945441-(Bromomethyl)-3-phenoxybenzeneHCID 516892Sodium Bicarbonate

Product 1

HCID 29891577N-(4-Nitrophenyl)-L-valine

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 962WaterSolvent2×HCID 6228DimethylformamideSolvent

Procedure

A mixture of 10 g of 4-fluoronitrobenzene, 5 g of valine and 10 g of sodium bicarbonate is dissolved in 200 ml of ethanol and 100 ml of water. The reaction mixture is refluxed for 3 hours and cooled. Excess 4-fluoronitrobenzene is removed by ether extraction and the aqueous phase is brought to pH 3 to 4 with hydrochloric acid. The oily precipitate is extracted with methylene chloride. After drying and removal of solvent, the residue is treated with 3 equivalents of sodium carbonate and 1 equivalent of m-phenoxybenzyl bromide in dimethylformamide as solvent. After stirring 24 hours the mixture is diluted with water and extracted with ether. The organic phase is washed with water, dried and the solvent removed. The crude ester is purified by preparative TLC to give the m-phenoxybenzyl ester of N-(p-nitrophenyl)valine.

Workup

  1. temperatureThe reaction mixture is refluxed for 3 hours
  2. temperaturecooled
  3. customExcess 4-fluoronitrobenzene is removed by ether extraction
  4. extractionThe oily precipitate is extracted with methylene chloride
  5. customAfter drying
  6. customremoval of solvent
  7. extractionextracted with ether
  8. washThe organic phase is washed with water
  9. customdried
  10. customthe solvent removed
  11. customThe crude ester is purified by preparative TLC

Sources & evidence

ORD record
ord-85b914a7e312417cb6db545fab2998d7
Source dataset
uspto-grants-1983_10
Patent number
US04411912

Reaction notes

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