NBS allylic bromination of cyclohexene; 3-Bromocyclohexene
Submitted Aug 28, 2001, published Aug 28, 2001
Benzoyl peroxide (0.35 g) was added to a mixture of cyclohexene (35 g; 0.43 mol) and N-bromosuccinimide (24.9 g; 0.14 mol) in carbon tetrachloride (100 cm3). The mixture was stirred for 2 hours, then heated slowly to reflux, and maintained at reflux for 3.5 hours. The mixture was cooled, filtered and concentrated, then distilled at reduced pressure (b.p. 61 oC @ 12 mmHg) to give 3-bromocyclohexene as a colourless oil (15.71 g; 70%).
1H nmr (CDCl3) 1.60-2.35 (6H, m), 4.85 (1H, m), 5.75-6.00 (2H, m)
A. J. McCarroll, PhD Thesis, University of St Andrews, 2000.
B. S. Furniss, A. J. Hannaford, P. W. G. Smith and A. R. Tatchell, "Vogel's Textbook of Organc Chemistry, 5th Edition," Longman, Harlow, 1989.
Keywords: Allylic, bromination, radical, benzoyl peroxide, carbon tetrachloride, symmetric, N-bromosuccinimide, dibenzoyl peroxide, 144