2-Bromoacetophenone

Introduction

2-Bromoacetophenone (C₈H₇BrO, mp 48-51 ˚C), also known in the literature either as ω-bromoacetophenone or phenacyl bromide, is a crystalline powder with a very sharp odor. It is a highly toxic and corrosive compound and a powerful lachrymator. Further, the reagent is harmful if swallowed or inhaled and causes irritation to skin and mucous membranes. 2-Bromoacetophenone is a stable compound, but incompatible with strong bases and strong oxidizing agents. The versatile reagent is a useful precursor of many organic compounds and is primarily used as an intermediate in pharmaceuticals and other fine chemical industries. It can be prepared by bromination ­of acetophenone in dry ether using AlCl₃ as catalyst. [¹] 2-Bromoacetophenone reacts slowly with moisture to form HBr. Contact with metals should be avoided as mild corrosion occurs.

2-Bromoacetophenone has found wide applications in ­organic synthesis including the syntheses of indolizines, pyridines, dihydrofuran derivatives, etc. It is also a very useful reagent for the identification of organic acids as it easily converts them into the corresponding crystalline phenacyl esters. This versatile reagent was first reported in 1871. [²]

References

• 1 Cowper RM. Davidson LH. Org. Synth., Coll. Vol. II  1943,  480 
• 2 Emmerling A. Engler C. Ber.  1871,  4:  147 
• 3 Bora U. Saikia A. Boruah RC. Org. Lett.  2003,  5:  435 
• 4 Yadav JS. Subba Reddy BV. Biswas SK. Sengupta S. Vishnumurthy P. Tetrahedron Lett.  2008,  49:  1034 
• 5 Das B. Reddy VS. Ramu R. J. Mol. Catal. A: Chem.  2006,  252:  235 
• 6 Wang QF. Hou H. Hui L. Yan C.-G. J. Org. Chem.  2009,  74:  7403 
• 7 Samuel R. Asokan CV. Suma S. Chandran P. Retnamma S. Anabha ER. Tetrahedron Lett.  2007,  48:  8376 
• 8 Borthakur M. Dutta M. Gogoi S. Boruah RC. Synlett  2008,  3125