Propargyl bromide → 1-tert-Butyl-3-prop-2-ynyl-imidazolidin-2-one

HRID 911561Notes

Reaction equation

[C:1]([N:5]1[CH2:9][CH2:8][NH:7][C:6]1=[O:10])([CH3:4])([CH3:3])[CH3:2].[CH2:11]([Li])[CH2:12][CH2:13]C.C(Br)C#C>C1COCC1>[C:1]([N:5]1[CH2:9][CH2:8][N:7]([CH2:13][C:12]#[CH:11])[C:6]1=[O:10])([CH3:4])([CH3:3])[CH3:2]

Participants

Conditions

Temperature: -78 °C

Procedure

Dissolve 1-tert-butyl-imidazolidin-2-one (2 g, 14 mmol) in anhydrous THF (60 mL) and cool at −78° C. Slowly add n-butyllithium (6.8 mL, 17 mmol, 2.5 M solution in hexanes). Stir the solution for 30 min. Rapidly add propargyl bromide (3.2 mL, 28.2 mmol, 80% solution in toluene). Warm the solution to room temperature while stirring overnight Concentrate the reaction mixture in vacuo and filter the residue on a short pad of silica gel eluting with dichloromethane/diethyl ether (1:1) to give the title compound as a yellow oil that solidifies on standing (1.77 g, 70%). GC-MS m/z (%) 180 (M+, 7), 165 (100), 123 (12), 84 (17).

Workup

temperatureWarm the solution to room temperature
stirringwhile stirring overnight
concentrationConcentrate the reaction mixture in vacuo
filtrationfilter the residue on a short pad of silica gel eluting with dichloromethane/diethyl ether (1:1)

Sources & evidence

ORD record: ord-0ee701820c2f407887799e7c3e68e146
Source dataset: uspto-grants-2011_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08022062B2

Reaction notes

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