Hydrochloric Acid → 2-Methyl-4-(4-nitro-benzoyloxy)-pyrrolidine-1-carboxylic Acid T-butyl Ester

HRID 1071505Notes

Reaction equation

[C:1]([O:5][C:6]([N:8]1[CH2:12][CH:11]([OH:13])[CH2:10][CH:9]1[CH3:14])=[O:7])([CH3:4])([CH3:3])[CH3:2].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[N+:34]([C:37]1[CH:45]=[CH:44][C:40]([C:41](O)=[O:42])=[CH:39][CH:38]=1)([O-:36])=[O:35].CCOC(/N=N/C(OCC)=O)=O.Cl>C1COCC1.CCCCCC.C(OCC)(=O)C>[C:1]([O:5][C:6]([N:8]1[CH2:12][CH:11]([O:13][C:41](=[O:42])[C:40]2[CH:39]=[CH:38][C:37]([N+:34]([O-:36])=[O:35])=[CH:45][CH:44]=2)[CH2:10][CH:9]1[CH3:14])=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

Conditions

Temperature: 0 °C

Procedure

The 4-hydroxy-2-methyl-pyrrolidine-1-carboxylic acid t-butyl ester (300.00 mg, 1.49 mmol) and triphenyl phosphine (512.54, 1.95 mmol) were dissolved in anhydrous THF and added to a mixture of para-nitrobenzoic acid (249.00 mg, 1.49 mmol) and DEAD (268.00 mg, 1.54 mmol, 0.24 mL) in anhydrous THF at 0° C. under argon. The mixture was stirred for 1 h at 0° C. After 1 h the TLC indicated no starting material remained and the reaction mixture was poured into a 1N HCl solution and the aqueous layer was extracted three times with ethyl acetate. The combined organic layers were washed with water and brine then dried over MgSO4. The solution was filtered and the solvent removed under reduced pressure. The product was isolated by flash chromatography. (2:1 hexane-ethyl acetate) Yield 391.54 mg.

Workup

waitAfter 1 h the TLC indicated
extractionthe aqueous layer was extracted three times with ethyl acetate
washThe combined organic layers were washed with water and brine
dry with materialthen dried over MgSO4
filtrationThe solution was filtered
customthe solvent removed under reduced pressure
customThe product was isolated by flash chromatography

Sources & evidence

ORD record: ord-23021509e741490fbf90d106cf552d1c
Source dataset: uspto-grants-2005_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06906067B2

Reaction notes

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