Nitric Acid → HCID 14771561, compound

Participants

Reaction Steps

To a solution of 85.5 g of 3,4-dihydro-4-methyl-3-oxo-2H-1,4-benzoxazine-8-carboxylic acid in 222 ml of concentrated sulfuric acid with cooling to -8° C. is added dropwise with stirring a mixture of 20.7 ml of fuming nitric acid (d 1.50) and 20.7 ml of concentrated sulfuric acid at a temperature below 2° C. over about 30 minutes, and the solution further stirred under cooling. The resultant solution is poured into ice-cold water with stirring. The precipitated crystals are collected by filtration, washed with water and dried to give 99 g of 3,4-dihydro-4-methyl-6-nitro-3-oxo-2H-1,4-benzoxazine-8-carboxylic acid, melting at 256°-259° C. with decomposition.

Provenance & Evidence