Ammonium Chloride → 4-Amino-N-((1,1-dimethylethoxy)carbonyl)-L-phenylalanine methyl ester

HRID 724656Notes

Reaction equation

HRID 724656 reaction equation
[C:1]([O:5][C:6]([NH:8][C@@H:9]([CH2:14][C:15]1[CH:20]=[CH:19][C:18]([N+:21]([O-])=O)=[CH:17][CH:16]=1)[C:10]([O:12][CH3:13])=[O:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].[Cl-].[NH4+]>CO.O.[Zn]>[NH2:21][C:18]1[CH:17]=[CH:16][C:15]([CH2:14][C@H:9]([NH:8][C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:7])[C:10]([O:12][CH3:13])=[O:11])=[CH:20][CH:19]=1

Participants

6

Reactant 2

HCID 25517Ammonium ChlorideHCID 11558856(S)-Methyl 2-((tert-butoxycarbonyl)amino)-3-(4-nitrophenyl)propanoate

Product 1

HCID 110118554-Amino-N-((1,1-dimethylethoxy)carbonyl)-L-phenylalanine methyl ester

Reagents, catalysts & solvents 3

HCID 23994ZincCatalystHCID 887MethanolSolventHCID 962WaterSolvent

Procedure

Methyl (2S)-2-[(tert-butoxycarbonyl)amino]-3-(4-nitrophenyl)propanoate (44.0 g, 136 mmol) in methanol (750 mL) and water (75 mL) was treated with ammonium chloride (10.9 g, 203 mmol) and then zinc (71 g, 1.1 mol). The solution was stirred at reflux for 1 h. The solution was filtered through celite, the residue concentrated under vacuum to remove methanol, the water solution extracted with ethyl acetate (500 mL) and dried over sodium sulfate. The product was a yellow foam (38.2 g, 96%). 1H NMR (400 MHz, CD3OD): δ 6.91 (d, J=8.4 Hz, 2H), 6.65 (d, J=8.3 Hz, 2H), 4.28–4.22 (m, 1H), 3.66 (s, 3H), 2.98–2.90 (m, 1H), 2.86–2.78 (m, 1H), 1.39 (s, 9H). LCMS found for C15H22N2O4Na (M+Na)+: m/z=317.

Workup

  1. temperatureat reflux for 1 h
  2. filtrationThe solution was filtered through celite
  3. concentrationthe residue concentrated under vacuum
  4. customto remove methanol
  5. extractionthe water solution extracted with ethyl acetate (500 mL)
  6. dry with materialdried over sodium sulfate

Sources & evidence

ORD record
ord-ad2dff11f415449595b6d1997294d1a0
Source dataset
uspto-grants-2006_11
Patent number
US07141596B2

Reaction notes

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