反应详情

温度

70 °C

After adding 6 N aqueous sodium hydroxide (180 ml, 900 mmol) to a solution of the 1-[4-acetyl-8-(tert-butyl)-3,4-dihydro-2H-1,4-benzoxazin-6-yl]-1-ethanone (36.8 g, 134 mmol) in methanol (360 ml) under a nitrogen atmosphere, the mixture was stirred at 70° C. for 40 minutes. The methanol was distilled off under reduced pressure, and the precipitated crystals were filtered out and dried under reduced pressure to yield the title compound (30.6 g, 98.1% yield) as bright golden yellow crystals.

1. distillationThe methanol was distilled off under reduced pressure
2. filtrationthe precipitated crystals were filtered out
3. customdried under reduced pressure