NITRATION AGENTS AND METHODS MORE RARELY USED 83acetylene and the ethyl ester of II reacted at room temperature in nitric acid solu-
tion. 3,3-Diisoxazolylketone (IX) is formed in a similar way from acetylene, acetone
and nitric acid, according to Quilico and Freri [10] and Quilico and Simonetta
[12]:VIVII(4)Acetyl methyl nitrolic acid (VI) is the well known product of the reaction of
HNO 3 on acetone. After loosing HNO 2 it condenses with acetylene to yield 3-acety-
lisoxazole (VII). Through the same sequence of reactions it eventually forms IX.
Dimerization of the nitrile oxide (VIII) yields diisoxazoylfuroxane (X).
All the isoxazole derivatives formed from acetylene belong to the 3-mono-
substituted series (Quilico [12a]).
On the formation of furoxane derivatives see also Wieland’s work on the action
of N 2 O 3 on unsaturated compounds p. 101.NITRATION WITH DILUTE NITRIC ACID
Konovalov [15] nitrated aliphatic hydrocarbons in sealed tubes at 120-130°C,
using dilute nitric acid of concentration 6.5-19%. From normal hydrocarbons
he obtained secondary nitro compounds in yields varying from 40% (2-nitro-
hexane from hexane) to 49-50% (2-nitrooctane from octane). Aromatic hydro-
carbons with an aliphatic substituted group when nitrated under the same con-
ditions gave nitro derivatives with a nitro group in the side chain. For example,
ethylbenzene, when nitrated with 12.5% nitric acid at 105-108°C, gives phenyl-
nitroethane in 44% yield. The optimum yield is obtained with 13% acid.