2-Methyl-5-(pyrrolidin-1-yl)-pent-3-yn-2-ol → 4-Hydroxy-4-methyl-1-(pyrrolidin-1-yl)-pent-1-en-3-one

HRID 1584644Notes

Reaction equation

[CH3:1][C:2]([OH:12])([C:4]#[C:5][CH2:6][N:7]1[CH2:11][CH2:10][CH2:9][CH2:8]1)[CH3:3].ClC1C=C(C2C=CC=CC=2C(OO)=[O:23])C=CC=1>ClCCl>[OH:12][C:2]([CH3:1])([CH3:3])[C:4](=[O:23])[CH:5]=[CH:6][N:7]1[CH2:8][CH2:9][CH2:10][CH2:11]1

Participants

Conditions

Temperature: 0 °C

Procedure

To an ice cold solution of 2-methyl-5-(pyrrolidin-1-yl)-pent-3-yn-2-ol (0.25 g) in dichloromethane (6 ml) was added in small portions 3-chlorophenylperoxybenzoic acid (0.285 g) over a period of about 2 minutes. After the reaction was stirred at 0° C. for 5 minutes, the mixture was passed over 20 weight equivalents of basic alumina (Brockmann Grade I, 150 mesh) and eluted with 5% methanol in dichloromethane. All fractions containing the desired amine N-oxide were combined and evaporated to near dryness in vacuo. The resulting residue was dissolved in methanol (20 ml) and heated to reflux temperatures for 7 hours. The solvent was then removed in vacuo and the residue was chromatographed over silica gel (50% ethyl acetate in hexanes was used as the eluant) to provide the desired product as an amber solid. MS(+ES), m/z: 184 (M+H)+.

Workup

washeluted with 5% methanol in dichloromethane
additionAll fractions containing the desired amine N-oxide
customevaporated
dissolutionThe resulting residue was dissolved in methanol (20 ml)
temperatureheated
temperatureto reflux temperatures for 7 hours
customThe solvent was then removed in vacuo
customthe residue was chromatographed over silica gel (50% ethyl acetate in hexanes

Sources & evidence

ORD record: ord-f286b799d40e487aa9c5aafb70ae6252
Source dataset: uspto-grants-1999_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05932745

Reaction notes

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