Lithium hydroxide, monohydrate → HCID 21950315, compound

HRID 1192341Notes

Reaction equation

HRID 1192341 reaction equation
C([O:3][C:4](=[O:23])[CH:5]([C:16]1[CH:21]=[CH:20][C:19]([Cl:22])=[CH:18][CH:17]=1)[CH2:6][CH2:7][NH:8][C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])C.O.[OH-].[Li+]>C1COCC1.O>[C:12]([O:11][C:9]([NH:8][CH2:7][CH2:6][CH:5]([C:16]1[CH:21]=[CH:20][C:19]([Cl:22])=[CH:18][CH:17]=1)[C:4]([OH:23])=[O:3])=[O:10])([CH3:15])([CH3:13])[CH3:14]

Participants

5

Reactant 2

HCID 168937Lithium hydroxide, monohydrateHCID 67540049HCID 67540049, compound

Product 1

HCID 21950315HCID 21950315, compound

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

The 4-tert-butoxycarbonylamino-2-(4-chlorophenyl)-butyric acid ethyl ester (5.61 g, 16.4 mmol) was dissolved in 40 mL of THF and 10 mL of water, then cooled to 0° C. The mixture was treated with lithium hydroxide mono-hydrate (1.38 g, 32.8 mmol) to afford a yellow solution. The ice-bath was removed, and the mixture was allowed to stir overnight to room temperature. The reaction mixture was concentrated to approximately 15 mL and diluted with water. The aqueous was washed with ethyl acetate (discarded) then treated with 3M HCl solution until acidic (pH=2-3). The resulting white precipitate was extracted with ethyl acetate, and the organics were combined. The organic was washed with brine, separated, dried over MgSO4, filtered, and concentrated in vacuo to afford the 4-tert-butoxycarbonylamino-2-(4-chlorophenyl)-butyric acid as a colorless oil. The material was re-dissolved in a minimal amount of warm (60° C.) hexanes and re-concentrated to afford the pure desired product as a white foam. 1H NMR (CDCl3, 400 MHz) δ 12.05-9.51 (brs, 1H), 7.31-7.25 (m, 4H), 4.59 (brs, 1H), 3.61 (d, J=7.6 Hz, 1H), 3.14 (brs, 2H), 2.28 (m, 1H), 1.92 (m, 1H), 1.43 (s, 9H).

Workup

  1. customto afford a yellow solution
  2. customThe ice-bath was removed
  3. concentrationThe reaction mixture was concentrated to approximately 15 mL
  4. additiondiluted with water
  5. washThe aqueous was washed with ethyl acetate (discarded)
  6. additionthen treated with 3M HCl solution until acidic (pH=2-3)
  7. extractionThe resulting white precipitate was extracted with ethyl acetate
  8. washThe organic was washed with brine
  9. customseparated
  10. dry with materialdried over MgSO4
  11. filtrationfiltered
  12. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-a82d6dc97c48456995e15149dda3f5b6
Source dataset
uspto-grants-2014_03
Patent number
US08680114B2

Reaction notes

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