Triethylamine → 3-Bromopyridine-2-carbonitrile

Participants

Reaction Steps

Under nitrogen, a solution of 156 g (0.90 mol) of 3-bromopyridine N-oxide from step 1 was dissolved in 1000 mL of acetonitrile and treated with 256 mL (1.84 mol) of triethylamine and 275 g (2.8 mol) of trimethylsilyl cyanide. The reaction was stirred at reflux overnight and concentrated in vacuo; the residue was dissolved in 2.5 M aqueous sodium hydroxide and extracted with methylene chloride. The organic phase was dried (MgSO4) and concentrated in vacuo; this residue was decolorized with carbon and recrystallized from methanol to give 42.2 g (26%) of 2-cyano-3-bromopyridine as a cream colored solid: mp 97°-98° C.; NMR (CDCl3) δ7.42 (dd, J=8 and 5 Hz, 1H), 8.05 (dd, J=8 and 2 Hz, 1H), 8.67 (dd, J=5 and 2 Hz, 1H).

Provenance & Evidence