Nitric Acid → Nitro-oxazine

Participants

Reaction Conditions

Reaction Steps

To concentrated sulfuric acid (13 ml) was added portion wise the oxazine IX (3.0 mmol) at 22° C., the solution obtained was cooled to 0° C. and treated with red fuming nitric acid (HNO3) (0.19 ml) over 20 min and stirring was continued at 0° C. for 1 h. The reaction mixture was slowly added to crushed ice (60 g), the pH was adjusted to 10 using sodium hydroxide (NaOH), the aqueous layer was extracted with AcOEt, the organic layer was dried, evaporated and the residue was chromatographed on silica using a mixture of AcOEt/MeOH (9:1) to afford the pure nitro-oxazine X.

Provenance & Evidence