Nitric Acid → 6-Nitro-2H-pyrido[3,2-B][1,4]oxazin-3(4H)-one

Reaction equation

[O:1]1[CH2:6][C:5](=[O:7])[NH:4][C:3]2[N:8]=[CH:9][CH:10]=[CH:11][C:2]1=2.[N+:12]([O-])([OH:14])=[O:13]>C(O)(=O)C.C(OC(=O)C)(=O)C>[N+:12]([C:9]1[CH:10]=[CH:11][C:2]2[O:1][CH2:6][C:5](=[O:7])[NH:4][C:3]=2[N:8]=1)([O-:14])=[O:13]

Participants

Procedure

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.