Azobisisobutyronitrile → Methyl 4'-(bromomethyl)biphenyl-2-carboxylate

Participants

Reaction Steps

A 47.46 g (210 mmol) sample of methyl 2-(p-tolyl)benzoate (Chemo Dynamics Inc.) was dissolved in 3 L of carbon tetrachloride and treated with 37.33 g (209 mmol) of N-bromosuccinimide (NBS) and 1.17 g (7.13 mmol) of azobisisobutyronitrile (AIBN) at reflux under nitrogen for 24 hours. The reaction mixture was treated again with 1.0 g (6.1 mmol) of AIBN and stirred at reflux for an additional 24 hours. The reaction was filtered and the solvent removed in in vacuo. Purification by silica gel chromatography (Waters Prep-500A) using ethyl acetate/hexane (5:95) as eluent provided 50.0 g (78%) of a colorless solid: mp 48–51° C.; NMR (CDCl3) δ 3.64 (s, 3H), 4.54 (s, 2H), 7.23–7.63 (m, 7H), 7.81–7.89 (m, 1H). NMR indicated that this material was only 91% pure; it contained 9% of the corresponding dibromocompound (δ 6.70); however, no further attempts at purification were made and this mixture was used in all subsequent alkylation reactions.

Provenance & Evidence