On the bromination of 1,2,3‐triphenylazulene

Abstract The bromination of 1,2,3‐triphenylazulene ( 1 ) with a tenfold excess of bromine in CHCl 3 /CCl 4 as solvent yields 5,7‐dibromo‐1,3‐bis( p ‐bromophenyl)‐2‐phenylazulene and not a dibromo derivative as reported earlier 1,2 . With 1.0 equivalent of bromine or 2.0 equivalents of NBS, a mixture of the 5‐bromo and 5,7‐dibromo derivatives of 1 is obtained.