p-Toluenesulfonic acid monohydrate → Methyl (S)-2-benzyloxycarbonylamino-4-oxopentanoate

HRID 19308Notes

Reaction equation

HRID 19308 reaction equation
[CH3:1][O:2][C:3](=[O:27])[C@@H:4]([NH:16][C:17]([O:19][CH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)=[O:18])[CH2:5][C:6](=[O:15])[CH2:7]C(OC(C)(C)C)=O.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3](=[O:27])[C@@H:4]([NH:16][C:17]([O:19][CH2:20][C:21]1[CH:22]=[CH:23][CH:24]=[CH:25][CH:26]=1)=[O:18])[CH2:5][C:6](=[O:15])[CH3:7]

Participants

4

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 57535371(S)-2-Benzyloxycarbonylamino-4-oxo-hexanedioic acid 6-tert-butyl ester 1-methyl ester

Product 1

HCID 13857370Methyl (S)-2-benzyloxycarbonylamino-4-oxopentanoateYield 80%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

In a flask under argon was placed (S)-2-benzyloxycarbonylamino-4-oxo-hexanedioic acid 6-t-butyl ester 1-methyl ester (3.04 g, 8.01 mmol), toluene (80 mL) and para-toluene sulfonic acid hydrate (115 mg, 0.61 mmol) and refluxed for 6.5 h and then overnight for 16 h at room temperature. The mixture was concentrated in vacuo and purified by flash column chromatography (silica gel 60, 230-400 mesh; 50% ethyl acetate/hexanes) which afforded (S)-2-benzyloxycarbonylamino-4-oxo-pentanoic acid methyl ester (1.79 g, 80%) as a pale yellow viscous oil.

Workup

  1. customIn a flask under argon was placed
  2. concentrationThe mixture was concentrated in vacuo
  3. custompurified by flash column chromatography (silica gel 60, 230-400 mesh; 50% ethyl acetate/hexanes) which

Sources & evidence

ORD record
ord-ffd6ce58172a4059b3e1d75a336a8869
Source dataset
uspto-grants-2010_06
Patent number
US07741327B2

Reaction notes

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