Nitric Acid → HCID 54703487, compound

Participants

Reaction Conditions

Reaction Steps

0.02 Mole 9-chloro-5,6-dihydro-6-methyl-2,5-dioxo-2H-pyrano[3,2-c]quinoline-4-ol from Example 7 (5.6 g) is suspended in 25 ml of glacial acetic acid. 4 ml of nitric acid (d=1.40) are added dropwise at 25° C., while stirring, and the magma-like reaction batch is then heated for 60 minutes to 95° C. It is then cooled to 20° C. During cooling, 36 ml of a mixture of water and isopropanol (1:1) is added. The whole is then filtered. The filter residue is washed with water to neutrality and after washing with isopropanol and petroleum ether, it is dried. 5.5 g (85% of the theory) of a crystalline residue are obtained, the crystals of which have a melting point of 241°-243° C. (decomp.) after recrystallization from a mixture of isobutanol and dimethylformamide.

Provenance & Evidence