1,3,5-Tribromobenzene

1,3,5-Tribromobenzene is an aryl bromide and isomer of tribromobenzene, also known as sym-tribromobenzene.

Preparation

Brominating aniline with elemental bromine gives 2,4,6-tribromoaniline. This is then diazotized, then reacted with ethanol to replace the diazonium group with hydrogen, forming 1,3,5-tribromobenzene.
It has also been prepared by these methods:

replacement of the amino group of 3,5-dibromoaniline with bromine
the action of light on bromoacetylene, effecting an alkyne trimerisation to 1,3,5-tribromobenzene
decomposition of 2,4,6-tribromophenylhydrazine
reduction of 2,4,6-tribromobenzenediazonium sulfate
a side product in the preparation of 2,4,6-tribromobenzonitrile

Reactions and uses

1,3,5-Tribromobenzene is a precursor to C₃-symmetric molecules. It undergoes a Suzuki reaction with three equivalents of 4-formylphenylboronic acid to form 1,3,5-tris(4-formylphenyl)benzene, a monomer for covalent organic frameworks.