反应详情

To a stirred aqueous solution of potassium ferricyanide (22.1 g; 673 mmol) (200 mL) in an ice bath, compound (4) (6.17 g; 26.9 mmol) and an aqueous sodium hydroxide (16.14 g; 404 mmol) (110 mL) were alternately added over 20 minutes. The resulting reaction mixture was stirred in an ice bath, and further stirred at room temperature for 3.5 hours. Crude crystals which precipitated out were separated by filtration and dried, and then dissolved in methanol, and subsequently subjected to an activated carbon treatment. Then, a filtrate was concentrated under reduced pressure to give 4.26 g (yield: 72% from compound (3)) of the title compound (5).

1. customThe resulting reaction mixture
2. stirringfurther stirred at room temperature for 3.5 hours
3. customCrude crystals which precipitated out
4. customwere separated by filtration
5. customdried
6. dissolutiondissolved in methanol
7. concentrationThen, a filtrate was concentrated under reduced pressure