反应详情

1b (2.411 g, 9.79 mmol) was suspended in 34 mL of 2M NaOH(aq) and dioxane (169.5 mL) at 15° C. This suspension was then treated with 28.85 mL of 30% aqueous hydrogen peroxide solution at 15° C. (dropwise addition over 15 minutes) causing the orange suspension to immediately lighten to an off-white colour and some material dissolved to form a pale orange-yellow solution. This mixture was then stirred at room temperature for a period of 60 minutes at room temperature during which time most of the off-white solid dissolved to form a turbid orange-yellow solution. The reaction mixture was then diluted with 319 mL of de-ionised water and acidified with 10% aqueous sulfuric acid (to pH 1). This caused the solution to deepen to a red-orange colour and after about 5-10 minutes a red-orange precipitate started to very slowly deposit from the solution. The mixture was then stirred vigorously at room temperature overnight during which time additional precipitate deposited from solution. The solid in the suspension was then collected by filtration (porosity 3 sinter) and washed with 2×150 mL portions of de-ionised water and air-dried on the sinter for 30 minutes. The deep red-orange solid was then further dried in vacuo in a vacuum oven at a vacuum pressure of 0.1 torr for a period of 24 hours at 40 deg C. Yield: 2.202 g (80.25%, red-orange powder).

1. customat 15° C
2. additiondropwise addition over 15 minutes)
3. dissolutionsome material dissolved
4. customto form a pale orange-yellow solution
5. dissolutiondissolved
6. customto form a turbid orange-yellow solution
7. waitto deepen to a red-orange colour and after about 5-10 minutes
8. stirringThe mixture was then stirred vigorously at room temperature overnight during which time additional precipitate
9. filtrationThe solid in the suspension was then collected by filtration (porosity 3 sinter)
10. washwashed with 2×150 mL portions of de-ionised water
11. customair-dried on the sinter for 30 minutes
12. customThe deep red-orange solid was then further dried in vacuo in a vacuum oven at a vacuum pressure of 0.1 torr for a period of 24 hours at 40 deg C