p-Toluenesulfonic acid monohydrate → 2-(3-Oxo-butyryl)-pyrrolidine-1-carboxylic acid benzyl ester

HRID 1170471Notes

Reaction equation

[CH2:1]([O:8][C:9]([N:11]1[CH2:15][CH2:14][CH2:13][CH:12]1[C:16](=[O:28])[CH:17](C(OC(C)(C)C)=O)[C:18](=[O:20])[CH3:19])=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH2:1]([O:8][C:9]([N:11]1[CH2:15][CH2:14][CH2:13][CH:12]1[C:16](=[O:28])[CH2:17][C:18](=[O:20])[CH3:19])=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 80 °C

Procedure

2-(2-tert-Butoxycarbonyl-3-oxo-butyryl)-pyrrolidine-1-carboxylic acid benzyl ester (9.74 g, 25.0 mmol) was dissolved toluene (40 mL) and was washed with 1N HCl (2×50 mL). To the resulting solution was added p-toluenesulfonic acid monohydrate (1.00 g, 5.00 mmol) and the solution was heated under nitrogen to 80° C. for 4 hours. The dark mixture was allowed to cool and was washed with water (3×100 mL). The organic layer was concentrated to give 6.87 g (95%) of 2-(3-oxo-butyryl)-pyrrolidine-1-carboxylic acid benzyl ester as an amber oil. The product was used directly in the subsequent step without further purification. [M+H]+ 290.03.

Workup

washwas washed with 1N HCl (2×50 mL)
temperatureto cool
washwas washed with water (3×100 mL)
concentrationThe organic layer was concentrated

Sources & evidence

ORD record: ord-1531cddb9f4c438a82e90fb23cddb3e1
Source dataset: uspto-grants-2010_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07825256B2

Reaction notes

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