Sodium Hydroxide → O-Ethyl-L-tyrosine

HRID 991275Notes

Reaction equation

HRID 991275 reaction equation
C(OC([NH:8][C@H:9]([C:20]([OH:22])=[O:21])[CH2:10][C:11]1[CH:16]=[CH:15][C:14]([O:17][CH2:18][CH3:19])=[CH:13][CH:12]=1)=O)(C)(C)C.O.C1(C)C=CC(S(O)(=O)=O)=CC=1.[OH-].[Na+]>C1COCC1>[CH2:18]([O:17][C:14]1[CH:15]=[CH:16][C:11]([CH2:10][C@@H:9]([C:20]([OH:22])=[O:21])[NH2:8])=[CH:12][CH:13]=1)[CH3:19]

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 521998p-Toluenesulfonic acid monohydrateHCID 7017903Boc-O-ethyl-L-tyrosine

Product 1

HCID 11275812O-Ethyl-L-tyrosine

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

N-tert-Butoxycarbonyl-O-ethyl-L-tyrosine (III, EXAMPLE 2, 195 g, 632 mmol) is suspended in THF (1200 mL), p-toluenesulfonic acid monohydrate (240 g, 1.26 mol) is added at 20-25°. The resulting mixture is heated at reflux for 2 hr. The mixture is neutralized with sodium hydroxide (2N, about 700 mL) to pH between 5 and 6 at 20-25°. The resulting mixture is stirred at 5° for 2 hr before it is filtered. The cake is washed with THF/water (4/1, 50 mL×3). The precipitate is dried to give the title compound. The filtrate is removed of all volatile, adjusted pH again to give more precipitate. The precipitate is dried to give additional title compound, NMR (D2O/NaOH) δ7.14, 6.88, 4.02, 3.40, 2.88, 2.73 and 1.30; CMR (D2O/NaOH) δ182.8, 157.0, 131.4, 131.0, 64.8, 57.8, 40.3 and 14.3.

Workup

  1. temperatureThe resulting mixture is heated
  2. temperatureat reflux for 2 hr
  3. filtrationis filtered
  4. washThe cake is washed with THF/water (4/1, 50 mL×3)
  5. customThe precipitate is dried

Sources & evidence

ORD record
ord-ff67a2b2712c4e4a84cf06425ff21e73
Source dataset
uspto-grants-2002_10
Patent number
US06462234B2

Reaction notes

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