Triethylamine → Boc-Tyr-OMe

HRID 916899Notes

Reaction equation

HRID 916899 reaction equation
Cl.[CH3:2][O:3][C:4](=[O:15])[C@H:5]([CH2:7][C:8]1[CH:13]=[CH:12][C:11]([OH:14])=[CH:10][CH:9]=1)[NH2:6].[C:16]([O:20][C:21](=O)[O:22]C(C)(C)C)([CH3:19])([CH3:18])[CH3:17].C(N(CC)CC)C>C1(C)C=CC=CC=1>[CH3:2][O:3][C:4](=[O:15])[C@H:5]([CH2:7][C:8]1[CH:9]=[CH:10][C:11]([OH:14])=[CH:12][CH:13]=1)[NH:6][C:21]([O:20][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:22]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 76956Methyl tyrosinate hydrochlorideHCID 10219638Carbonic acid, bis(1,1-dimethylethyl) ester

Product 1

HCID 7019130Boc-Tyr-OMeYield 95.5%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

L-tyrosine methyl ester hydrochloride 2 (104.3 g, 0.45 mol) and di-t-butylcarbonate (DBC, 98.2 g, 0.45 mol) were suspended in toluene (521.3 g), and triethylamine (50.1 g, 0.495 mol) was added dropwise thereto at 20° C. over 1.5 hrs. After further keeping at 20° C. for 4 hrs, the reaction mass was washed with 5% hydrochloric acid (328.1 g) and 5% aqueous sodium bicarbonate (378.1 g). The toluene solution thus obtained was dried over suitable amount of magnesium sulfate and then concentrated to about a half of the volume under reduced pressure. To the concentrate was added dropwise n-hexane (329.5 g) at room temperature over 1 hr. After keeping at 0° C. overnight, precipitates were filtered and dried under reduced pressure to give N-Boc-L-tyrosine methyl ester 3 (126.9 g, yield 95.5%) as white crystals.

Workup

  1. waitAfter further keeping at 20° C. for 4 hrs
  2. washthe reaction mass was washed with 5% hydrochloric acid (328.1 g) and 5% aqueous sodium bicarbonate (378.1 g)
  3. customThe toluene solution thus obtained
  4. dry with materialwas dried over suitable amount of magnesium sulfate
  5. concentrationconcentrated to about a half of the volume under reduced pressure
  6. additionTo the concentrate was added dropwise n-hexane (329.5 g) at room temperature over 1 hr
  7. waitAfter keeping at 0° C. overnight
  8. customprecipitates
  9. filtrationwere filtered
  10. customdried under reduced pressure

Sources & evidence

ORD record
ord-ec2add6e5ab3420ea62e027624616f1d
Source dataset
uspto-grants-2007_09
Patent number
US07271280B2

Reaction notes

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