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120 CHEMISTRY AND TECHNOLOGY OF EXPLOSIVES

(71)

(72)

T. Urbanski and Kutkiewicz [70] found that 5-nitro-8-hydroxyquinoline, when

boiled with a solution of sodium nitrite in 10% hydrochloric or sulphuric acid,

yielded 5,7-dinitro-8-hydroxyquinoline:

(73)

The sodium nitrite is used in an excess. The yield of dinitro-8-hydroxyquinoline

obtained amounts to about 30% (cf. also the reaction 7, p. 85). The mechanism

of this reaction cannot consist in the formation of a nitroso compound which

would be oxidized to a nitro compound, as no nitrosation of a nitrophenol is

known.

NITROUS ACID IN THE PRESENCE OF HYDROGEN PEROXIDE

Hydrogen peroxide reacts with nitric and nitrous acids to form the correspond-

ing pernitric acids, of which pernitrous acid is a better defined compound. Baeyer

and Williger [163] reported the possibility of obtaining it by reacting ethylhydro-

peroxide with alkyl nitrate. Raschig [164] has studied the action of hydrogen per-

oxide on nitrous acid and found such a mixture to be a more powerful oxidizing

agent than each of the components taken separately.

Raschig was not correct in ascribing the structure of pernitric acid, HNO 3 ,

to the product of reaction of H 2 O 2 with HNO 2. Schmidlin and Massini [165] have

proved it to be a pernitrous acid HO-ONO. Extensive studies on pernitrous

acid have been carried out by Trifonov [166], who found that hydrogen peroxide

when reacted with nitrous acid formed the peroxide, N 2 O 6 , which gave nitrous

acid under the influence of water, the solution appearing yellow for a while.

Kortüm and Finckh [I67] found the absorption spectrum of the yellow so-

lution was similar to that of the nitrate ion, showing however some difference.

The kinetics of the reaction of nitrous acid with hydrogen peroxide have been