2-Bromopyridine → tert-Butyl 5',6'-dihydro-[2,4'-bipyridine]-1'(2'H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate (1 g, 3.23 mmol) in dioxane (35 ml) and water (2.0 ml) was added 2-bromopyridine (2.9 g, 18.35 mmol), K3PO4 (3.8 g, 17.90 mmol) and Pd(PPh3)4 (350 mg, 0.30 mmol), and the resulting mixture was allowed to react with stirring for 3 hours at 90° C. The reaction mixture was diluted with water (180 ml) and extracted with ethyl acetate (3×50 ml). The organic layers were combined, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to give the residue, which was purified via silica gel column chromatography (2% ethyl acetate in petroleum ether) to afford tert-butyl 4-(pyridin-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate as pink oil (1.1 g, 70%).

Provenance & Evidence