Nitric Acid → HCID 14771560, compound

Participants

Reaction Steps

To a solution of 60 g of 6-chloro-3,4-dihydro-4-methyl-3-oxo-2H-1,4-benzoxazine-8-carboxylic acid in 450 ml of concentrated sulfuric acid with cooling below 0° C. is added dropwise a mixture of 11.6 ml of fuming nitric acid and 11.6 ml of concentrated sulfuric acid at a temperature below 5° C. The resultant solution is stirred under ice-cooling for 2.5 hours and poured into ice-cold water. The precipitated crystals are collected by filtration and recrystallized from ethanol to give 6-chloro-3,4-dihydro-4-methyl-7-nitro-3-oxo-2H-1,4-benzoxazine-8-carboxylic acid, melting at 257° C. with decomposition.

Provenance & Evidence