Cesium carbonate → tert-Butyl (2S)-2-benzyloxycarbonylamino-3-(4-(3-ethoxycarbonylpropyloxy)phenyl)propionate

HRID 2297383Notes

Reaction equation

HRID 2297383 reaction equation
[C:1]([O:5][C:6](=[O:27])[C@H:7]([CH2:19][C:20]1[CH:25]=[CH:24][C:23]([OH:26])=[CH:22][CH:21]=1)[NH:8][C:9]([O:11][CH2:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)=[O:10])([CH3:4])([CH3:3])[CH3:2].C(=O)([O-])[O-].[Cs+].[Cs+].Br[CH2:35][CH2:36][CH2:37][C:38]([O:40][CH2:41][CH3:42])=[O:39]>CC(C)=O>[CH2:12]([O:11][C:9]([NH:8][C@@H:7]([CH2:19][C:20]1[CH:21]=[CH:22][C:23]([O:26][CH2:35][CH2:36][CH2:37][C:38]([O:40][CH2:41][CH3:42])=[O:39])=[CH:24][CH:25]=1)[C:6]([O:5][C:1]([CH3:4])([CH3:2])[CH3:3])=[O:27])=[O:10])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 76300Ethyl 4-bromobutyrateHCID 11428694Z-Tyr-OtBu

Product 1

HCID 11038228tert-Butyl (2S)-2-benzyloxycarbonylamino-3-(4-(3-ethoxycarbonylpropyloxy)phenyl)propionate

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

7.42 g (0.02 mol) of N-benzyloxycarbonyl-L-tyrosine tert-butyl ester were refluxed for 6 h together with 9.77 g(0.03 mol) of cesium carbonate and 3.9 g (0.02 mol) of ethyl 4-bromo-butyrate in about 60 ml of acetone. After cooling the reaction mixture, the solvent was removed in vacuo. The residue was partitioned between ethyl acetate and water (1/1). After separation of the phases, the organic phase was washed two times each with water and saturated sodium chloride solution, dried over sodium sulfate and concentrated in vacuo. The oily crude product was purified by flash chromatography on silica gel (dichloromethane/acetonitrile 25/1). Yield: 9.4 g (97%) of viscous oil. Rf=0.36 (silica gel, dichloromethane/methanol 9911).

Workup

  1. temperatureAfter cooling the reaction mixture
  2. customthe solvent was removed in vacuo
  3. customThe residue was partitioned between ethyl acetate and water (1/1)
  4. customAfter separation of the phases
  5. washthe organic phase was washed two times each with water and saturated sodium chloride solution
  6. dry with materialdried over sodium sulfate
  7. concentrationconcentrated in vacuo
  8. customThe oily crude product was purified by flash chromatography on silica gel (dichloromethane/acetonitrile 25/1)

Sources & evidence

ORD record
ord-fa2a55938ece4d1d9bf6450a5b79cd2c
Source dataset
uspto-grants-2002_12
Patent number
US06492356B1

Reaction notes

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