Water → L-Alanine 1,1-dimethylethyl ester

HRID 1380820Notes

Reaction equation

HRID 1380820 reaction equation
Cl.[N+:2]([C:5]1[CH:18]=[CH:17][C:8]([CH2:9][C@@H:10]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[NH2:11])=[CH:7][CH:6]=1)([O-:4])=[O:3].Br[CH:20]([CH3:28])[C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22].C([N:31](CC)CC)C.O>CN(C)C=O.CO.CCCCCC.C(OC(=O)C)C.CCCCCC>[CH2:15]([O:14][C:12]([C@@H:10]([NH:11][C@@H:20]([C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])[CH3:28])[CH2:9][C:8]1[CH:7]=[CH:6][C:5]([N+:2]([O-:4])=[O:3])=[CH:18][CH:17]=1)=[O:13])[CH3:16].[NH2:31][C@H:20]([C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])[CH3:28]

Participants

10

Reactant 4

HCID 962WaterHCID 8471TriethylamineHCID 545327tert-Butyl 2-bromopropanoateHCID 6453710Ethyl 4-nitro-3-phenyl-L-alaninate monohydrochloride

Product 2

HCID 89016L-Alanine 1,1-dimethylethyl esterHCID 9929091N-[1(S)-ethoxycarbonyl-2-(4-nitrophenyl)ethyl]-(R)alanine, t-butyl ester

Reagents, catalysts & solvents 4

HCID 887MethanolSolventHCID 6228DimethylformamideSolventHCID 8058HexaneSolventHCID 21226206Ethyl acetate hexaneSolvent

Procedure

To a solution of 4-nitrophenylalanine, ethyl ester, hydrochloride (54.0 g) in dry dimethylformamide (400 ml), add t-butyl 2-bromopropionate (112.3 g) and triethylamine (76 ml) and heat the resulting mixture at 70° for 18 hours under a nitrogen atmosphere. Pour the reaction mixture into water and extract with methylene chloride (6×300 ml). Combine the organic layers, dry over magnesium sulfate and concentrate in vacuo to give a liquid (contains DMF). Chromatograph this liquid on a Prep 500 (3 silica gel cartridges) using hexane (8 l) then hexane:ethylacetate 4:1 and isolate N-[1(S)-ethoxycarbonyl-2-(4-nitrophenyl)ethyl]-(R)alanine, t-butyl ester, [α]D26 =+24.7° (methanol), and N-1(S)-ethoxycarbonyl-2-(4-nitrophenyl)ethyl]-(S)alanine, t-butyl ester.

Workup

  1. temperatureheat the resulting mixture at 70° for 18 hours under a nitrogen atmosphere
  2. extractionextract with methylene chloride (6×300 ml)
  3. dry with materialCombine the organic layers, dry over magnesium sulfate
  4. concentrationconcentrate in vacuo
  5. customto give a liquid (contains DMF)

Sources & evidence

ORD record
ord-5a82902bc8024bd6868ad2accf6e967f
Source dataset
uspto-grants-1986_04
Patent number
US04584285

Reaction notes

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