Citric Acid → (S)-2-Amino-3-(3-bromo-4-fluoro-phenyl)-propionic acid tert-butyl ester

HRID 2265308Notes

Reaction equation

HRID 2265308 reaction equation
[C:1]([O:5][C:6](=[O:31])[C@@H:7]([N:17]=C(C1C=CC=CC=1)C1C=CC=CC=1)[CH2:8][C:9]1[CH:14]=[CH:13][C:12]([F:15])=[C:11]([Br:16])[CH:10]=1)([CH3:4])([CH3:3])[CH3:2].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C1COCC1.O>[C:1]([O:5][C:6](=[O:31])[C@@H:7]([NH2:17])[CH2:8][C:9]1[CH:14]=[CH:13][C:12]([F:15])=[C:11]([Br:16])[CH:10]=1)([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 2

HCID 311Citric AcidHCID 86761241(S)-2-(Benzhydrylidene-amino)-3-(3-bromo-4-fluoro-phenyl)-propionic acid tert-butyl ester

Product 1

HCID 68770438(S)-2-Amino-3-(3-bromo-4-fluoro-phenyl)-propionic acid tert-butyl esterYield 124.8%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of (S)-2-(benzhydrylidene-amino)-3-(3-bromo-4-fluoro-phenyl)-propionic acid tert-butyl ester (300 mg, 0.622 mmol) in THF (3 mL) was treated with 10% citric acid (3 mL). The mixture was stirred overnight, diluted with water, and extracted with Et2O (2×). The aqueous layer was basified to pH=10 with satd. aq. K2CO3 and extracted with EtOAc (3×). The combined organic layers were dried (MgSO4) and concentrated to give the title compound (247 mg, 64%). MS (ESI+): mass calcd. for C13H17BrFNO2, 318.18; m/z found, 262.2 [M-t-Bu]+. 1H NMR (400 MHz, CDCl3): 7.42 (dd, J=6.6, 2.1 Hz, 1H), 7.16-7.11 (m, 1H), 7.08-7.02 (m, 1H), 3.56 (dd, J=7.3, 5.9 Hz, 1H), 2.85-2.78 (m, 1H), 2.99-2.92 (m, 1H), 1.43 (m, 9H).

Workup

  1. extractionextracted with Et2O (2×)
  2. extractionaq. K2CO3 and extracted with EtOAc (3×)
  3. dry with materialThe combined organic layers were dried (MgSO4)
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-1e880e05a8564472b4fbad666cb9595a
Source dataset
uspto-grants-2010_12
Patent number
US07855292B2

Reaction notes

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