反应详情

温度

65 °C

To 2-methyl-6-benzoxazole carboxylic acid (1.060 g) in toluene (111 ml) solution, triethylamine (0.867 ml) and N,N-dimethylformamide (22 ml) were added. To this mixture, diphenyl phosphoryl azide (1.65 ml) was added and stirred at 65° C. for an hour. The reaction mixture was cooled to room temperature, added with 4-amino-1,5-naphthyridine (0.878 g), and the resulting mixture was stirred at 65° C. for another 72 hours. The cooled mixture was diluted with ethyl acetate and washed with a saturated aqueous sodium carbonate. The organic layer was dried with magnesium sulfate and the solvent was distilled away to obtain a crude product of 1-(2-methylbenzoxazole-6-yl)-3-[1,5]naphthyridine-4-yl urea for 0.797 g. The crude product was dissolved in ethyl acetate at 60° C., added with 4N-hydrogen chloride-ethyl acetate solution and stirred on ice. The precipitated hydrochloride was filtrated, air-dried at 60° C. to obtain 840 mg of the title compound (CAS No. 249889-64-3). The structure of the obtained title compound and results from NMR measurement were as follows.

1. temperatureThe reaction mixture was cooled to room temperature
2. stirringthe resulting mixture was stirred at 65° C. for another 72 hours
3. washwashed with a saturated aqueous sodium carbonate
4. dry with materialThe organic layer was dried with magnesium sulfate
5. distillationthe solvent was distilled away