tert-Butyl bromoacetate → N-[2-(1,1-Dimethylethoxy)-2-oxoethyl]-L-tryptophan 1,1-dimethylethyl ester

HRID 2185589Notes

Reaction equation

HRID 2185589 reaction equation
[CH3:1][C:2]([O:5][C:6](=[O:19])[C@H:7]([CH2:9][C:10]1[C:18]2[C:13](=[CH:14][CH:15]=[CH:16][CH:17]=2)[NH:12][CH:11]=1)[NH2:8])([CH3:4])[CH3:3].Br[CH2:21][C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23]>CC#N>[CH3:4][C:2]([O:5][C:6](=[O:19])[C@H:7]([CH2:9][C:10]1[C:18]2[C:13](=[CH:14][CH:15]=[CH:16][CH:17]=2)[NH:12][CH:11]=1)[NH:8][CH2:21][C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])([CH3:1])[CH3:3]

Participants

4

Reactant 2

HCID 79177tert-Butyl bromoacetateHCID 7020175(S)-tert-Butyl 2-amino-3-(1H-indol-3-yl)propanoate

Product 1

HCID 53674071N-[2-(1,1-Dimethylethoxy)-2-oxoethyl]-L-tryptophan 1,1-dimethylethyl esterYield 81.6%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To a solution of L-tryptophan 1,1-dimethylethyl ester (17.10 g; 65.68 mmol) in CH3CN (150 mL) 2M phosphate. buffer (pH 8; 150 mL) was added. Tert-butyl bromoacetate (10.7 mL; 72.25 mmol) was dropped into the mixture and vigorous mechanical stirring set on. The reaction was monitored by HPLC (Chromatographic method of Example 3, A)). After 23 h the organic layer was separated and concentrated to dryness to give a crude oil (26.62 g), which was purified by flash chromatography (silica gel; n-hexane/ethyl acetate, 8:2 v/v) to give the desired product (20.07 g; 53.59 mmol). Yield 54.5% starting from L-tryptophan.

Workup

  1. additionbuffer (pH 8; 150 mL) was added
  2. customAfter 23 h the organic layer was separated
  3. concentrationconcentrated to dryness
  4. customto give a crude oil (26.62 g), which
  5. customwas purified by flash chromatography (silica gel; n-hexane/ethyl acetate, 8:2 v/v)

Sources & evidence

ORD record
ord-7fac6fe0a85c443e8311e24ddf5f4fee
Source dataset
uspto-grants-2002_06
Patent number
US06403055B1

Reaction notes

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