反应详情

2H-Pyrido[3,2-b]-1,4-oxazin-3(4H)-one (2.5 g) was dissolved in acetic acid (6 mL) and acetic anhydride (30 mL). Fuming nitric acid (3 mL) was added dropwise to the reaction solution in ice-bath. The reaction solution was stirred in ice-bath overnight. Solution was poured into crashed ice. The light yellow precipitation was collected by filtration, washed with water and dried to give a mixture of nitrated products (regio-isomers). The mixture was crystallized from dichloromethane to give 6-nitro-2H-pyrido[3,2-b]-1,4-oxazin-3(4H)-one (1 g) as a light yellow solid.

1. additionSolution was poured
2. customThe light yellow precipitation
3. filtrationwas collected by filtration
4. washwashed with water
5. customdried
6. customto give
7. additiona mixture of nitrated products (regio-isomers)
8. customThe mixture was crystallized from dichloromethane