Lithium Hydroxide → N-Boc-O-isopropyl-L-tyrosine

HRID 449475Notes

Reaction equation

HRID 449475 reaction equation
[OH-].[Li+].[C:3]([O:7][C:8]([NH:10][C@@H:11]([CH2:16][C:17]1[CH:22]=[CH:21][C:20]([O:23][CH:24]([CH3:26])[CH3:25])=[CH:19][CH:18]=1)[C:12]([O:14]C)=[O:13])=[O:9])([CH3:6])([CH3:5])[CH3:4]>O.CO>[C:3]([O:7][C:8]([NH:10][C@@H:11]([CH2:16][C:17]1[CH:22]=[CH:21][C:20]([O:23][CH:24]([CH3:26])[CH3:25])=[CH:19][CH:18]=1)[C:12]([OH:14])=[O:13])=[O:9])([CH3:5])([CH3:6])[CH3:4]

Participants

5

Reactant 2

HCID 3939Lithium HydroxideHCID 59496538(S)-methyl 2-(tert-butoxycarbonylamino)-3-(4-isopropoxyphenyl)propanoate

Product 1

HCID 18601565N-Boc-O-isopropyl-L-tyrosineYield 90%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

Lithium hydroxide (160 mg, 6.8 mmol) in water (10 mL) was added to a solution of (S)-methyl 2-(tert-butoxycarbonylamino)-3-(4-isopropoxyphenyl)propanoate in methanol (30 mL). The reaction was stirred for 24 h., and was concentrated under reduced pressure to remove the methanol. The remaining water layer was adjusted to pH=3 using 1 N HCl aqueous solution, and was extracted with ethyl acetate. The organic phase was washed with saturated brine, dried over magnesium sulfate, filtered and concentrated under reduced pressure to give the crude product (2S)-2-[(tert-butoxycarbonyl)amino]-3-(4-isopropoxyphenyl)propanoic acid (1 g, 90%). Analytical LCMS (M+H-Boc)+: m/z=223.9.

Workup

  1. concentrationwas concentrated under reduced pressure
  2. customto remove the methanol
  3. extractionwas extracted with ethyl acetate
  4. washThe organic phase was washed with saturated brine
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-872b497727b54a74aaa980821f490610
Source dataset
uspto-grants-2013_07
Patent number
US08481732B2

Reaction notes

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