Ethylmagnesium bromide

Ethylmagnesium bromide
Identifiers
CAS number 925-90-6 Y
PubChem 101914
ChemSpider 10254342 Y
Jmol-3D images Image 1
Properties
Molecular formula C2H5BrMg
Molar mass 133.27 g mol−1
Hazards
MSDS Oxford MSDS
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Ethylmagnesium bromide is a Grignard reagent with formula C2H5MgBr or C2H5Mg+·Br, namely a magnesium ion with a covalent bond to an ethyl group and an ionic bond to a bromine anion. It is widely used in the laboratory synthesis of organic compounds.

Reactions

Apart from acting as the synthetic equivalent of an ethyl anion synthon for nucleophilic addition, ethylmagnesium bromide may be used as a strong base to deprotonate various substrates such as alkynes:[1][2][3]

RC≡CH + EtMgBr → RC≡CMgBr + EtH

In this application, ethylmagnesium bromide has been supplanted by the wide availability of organolithium reagents.

Preparation

Ethylmagnesium bromide is commercially available, usually as a solution in diethyl ether or tetrahydrofuran. It may be prepared in the normal manner of Grignard reagents — by reacting bromoethane with magnesium in diethyl ether:[4]

EtBr + Mg → EtMgBr

References

  1. ^ Taniguchi, H.; Mathai, I. M.; Miller, S. I., "1-Phenyl-1,4-Pentadiyne and 1-Phenyl-1,3-Pentadiyne", Org. Synth. 50: 97, http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv6p0925 ; Coll. Vol. 6: 925 
  2. ^ A. J. Quillinan, A. J.; Scheinmann, F., "3-Alkyl-1-alkynes Synthesis: 3-Ethyle-1-hexyne", Org. Synth. 58: 1, http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv6p0595 ; Coll. Vol. 6: 595 
  3. ^ Newman, M. S.; Stalick, W. M., "1-Ethoxy-1-butyne", Org. Synth. 57: 65, http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv6p0564 ; Coll. Vol. 6: 564 
  4. ^ W. W. Moyer and C. S. Marvel, "Triethyl Carbinol", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv2p0602 ; Coll. Vol. 2: 602