Cesium carbonate → 8-(6-tert-butyl-1H-benzimidazol-2-yl)-4-(3-chloro-pyridin-2-yl)-3,4-dihydro-2H-benzo[1,4]oxazine

Participants

Reaction Conditions

Reaction Steps

3.1 g (10 mmol) of 4-(5-tert-butyl-1H-benzo[d]imidazol-2-yl)benzenamine (compound 1a) obtained Example 1 was dissolved in 10 mL of toluene. 1.5 g (10 mmol) of 2,3-dichloropyridine (compound 8), 0.1 g (0.5 mmol) of Pd(OAc)2, 0.5 g (0.8 mmol) of 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl and 4.6 g (14 mmol) of Cs2CO3 were added thereto and stirred at 90° C. for 12 hr. The reaction mixture was cooled to room temperature and concentrated under reduced pressure, followed by dilution with ethyl acetate. The resulting product was washed with saturated sodium bicarbonate solution and saturated sodium chloride solution, followed by drying over magnesium sulfate and concentrating under reduced pressure. The resulting residue was subjected to column chromatography (ethyl acetate/hexane=2/3) to obtain the title compound (4.0 g, yield: 95%).

Provenance & Evidence