Dimethylformamide → HCID 178440680, compound

Participants

Reaction Steps

3.6 g (20 mmol) of 3,4-dihydro-2H-benzo[b][1,4]oxazin-8-carboxylic acid obtained in (1-4) was dissolved in 50 mL of dimethylformamide. 3.3 g (20 mmol) of 4-tert-butylbenzene-1,2-diamine, 7 mL (40 mmol) of diisopropylethylamine and 11 g (30 mmol) of O-(7-azabenzotriazole-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate were added thereto, and stirred for 3 hr at room temperature. The reaction mixture was diluted with ethyl acetate and 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 dissolved in acetate/toluene (45 mL/5 mL) and stirred for 4 hr at 70° C., followed by cooling to room temperature and concentrating under reduced pressure. The concentrate was dissolved in ethyl acetate and washed with saturated sodium bicarbonate solution and saturated sodium chloride solution, followed by drying over magnesium sulfate and concentrating under reduced pressure. The obtained residue was subjected to column chromatography (ethyl acetate:hexane=1:1) to obtain the title compound (5.2 g, yield: 85%).

Provenance & Evidence