2-Bromotoluene → Biphenyl

Participants

Reaction Steps

Cyclization substrate 5 is synthesized in FIG. 1. The Suzuki reaction is iterated, first by coupling 1,3-dimethoxyphen-2-yl boronic acid with 2-bromotoluene with tetrakis(triphenylphosphine) palladium catalysis to give biphenyl compound 1. Regioselective bromination of 1 gave 2, followed by Suzuki reaction with pyridine-3-boronic acid under palladium catalysis to yield 3. Demethylation of 3 with hydrobromic acid and acetic acid gave 4, followed by Friedel-Crafts acylation with 2,5-dichlorotrimellitic anhydride to yield 5.

Provenance & Evidence