Boron trifluoride etherate → (alphaR,betaR)-N-benzyloxycarbonyl-5-chloro-1-ethyl-beta-methyltryptophan methyl ester

HRID 2165565Notes

Reaction equation

HRID 2165565 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[N:7]([CH2:11][CH3:12])[CH:6]=[CH:5]2.[CH2:13]([O:20][C:21]([N:23]1[C@H:25]([CH3:26])[C@@H:24]1[C:27]([O:29][CH3:30])=[O:28])=[O:22])[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.B(F)(F)F.CCOCC>C(Cl)Cl>[CH3:30][O:29][C:27](=[O:28])[C@@H:24]([C@H:25]([CH3:26])[C:5]1[C:4]2[C:8](=[CH:9][CH:10]=[C:2]([Cl:1])[CH:3]=2)[N:7]([CH2:11][CH3:12])[CH:6]=1)[NH:23][C:21]([O:20][CH2:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)=[O:22]

Participants

5

Reactant 3

HCID 8000Boron trifluoride etherateHCID 11161001methyl (2R,3R)-N-benzyloxycarbonyl-3-methyl-2-aziridinecarboxylateHCID 178991595-Chloro-1-ethyl-1H-indole

Product 1

HCID 14152055(alphaR,betaR)-N-benzyloxycarbonyl-5-chloro-1-ethyl-beta-methyltryptophan methyl esterYield 28.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 5-chloro-1-ethylindole (6.17 g) and methyl (2R,3R)-N-benzyloxycarbonyl-3-methyl-2-aziridinecarboxylate (9.87 g) in dry methylene chloride (100 ml) which was cooled on an ice bath, was added boron trifluoride etherate (4 ml). The mixture was stirred for five minutes and washed with saturated sodium bicarbonate solution, treated with active charcoal, and dried over magnesium sulfate. After removal of the solvent, the crude residue was chromatographed on silica gel (100 g) (toluene as eluent) to give (αR,βR)-N-benzyloxycarbonyl-5-chloro-1-ethyl-β-methyltryptophan methyl ester (4.17 g) as an oil.

Workup

  1. washwashed with saturated sodium bicarbonate solution
  2. additiontreated with active charcoal
  3. dry with materialdried over magnesium sulfate
  4. customAfter removal of the solvent
  5. customthe crude residue was chromatographed on silica gel (100 g) (toluene as eluent)

Sources & evidence

ORD record
ord-5f8873af779e4645a9deb1eea909f36b
Source dataset
uspto-grants-1990_07
Patent number
US04940709

Reaction notes

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