| Identification | Back Directory | [Name]
Propargylmagnesium Bromide | [CAS]
13254-27-8 | [Synonyms]
Prop-2-yn-1-yL
Propargylmagnesium Bromide
magnesium,prop-1-yne,bromide
Prop-2-yn-1-ylmagnesium bromide
Prop-2-yn-1-ylmagnesium bromide, 0.50 M in THF
Prop-2-yn-1-ylmagnesium bromide, 0.50 M in 2-MeTHF | [Molecular Formula]
C3H3BrMg | [MDL Number]
MFCD17013342 | [MOL File]
13254-27-8.mol | [Molecular Weight]
143.28 |
| Hazard Information | Back Directory | [Uses]
Propargylmagnesium Bromide is used to propargylation and propadienylation of electrophilic centers.
| [Preparation]
Propargylmagnesium Bromide was prepared from propargyl bromide and amalgamated magnesium, generated in
situ from Magnesium and Mercury(II) Chloride. Without HgCl2, only a mixture of acetylenic and allenic hydrocarbons is
obtained. Reaction at reflux temperature in ether using a recycling reactor results in a greater than 90% yield of Grignard
reagent consisting of a 4:1 ratio of allenic and acetylenic forms. Low temperature and slow addition of a dilute solution of a
mixture of propargylic bromide and substrate to a reacting mixture, initiated with a small amount of the bromide, is a technique
that reduces equilibration of the Grignard reagent before its reaction with the substrate. The same slow addition of a dilute
ether solution of propargyl bromide to an initiated reaction is said to lead to the pure allenic Grignard reagent. The Grignard
reagent prepared from propargyl bromide has been converted into a solid powder by complexation with tris(3,6-
dioxaheptyl)amine. | [storage]
Propargylmagnesium Bromide should be prepared and used when needed. Solutions undergo
disproportionation to propyne, allene, the acetylenic Grignard reagent, and di-Grignard reagent over days. The reagent is easily
hydrolyzed to gaseous hydrocarbons and must be handled and used in a dry and inert atmosphere. Pure propargyl bromide, the
compound required for preparing the Grignard reagent, is shock sensitive. Propargyl bromide is also supplied as an 80% by wt
solution in toluene, which does not show this hazardous property. |
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Matrix Scientific
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803 788-9494 All other calls |
| Website: |
www.matrixscientific.com |
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