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132 CHEMISTRY AND TECHNOLOGY OF EXPLOSIVES

for the preparation of 2,3,4- and 2,4,5-trinitrotoluencs from 3,4- or 4.5-dinitro-

o-toluidine. Holleman [211a] also used this method for the last stage of the prepa-

ration of tetranitrotoluene (p. 339).

In this way nitro derivatives of anthraquinone are prepared on an industrial

scale from corresponding derivatives of aminoanthraquinonc (Kopetsehni [212];

Mosby and Berry [213]). This is rather advantageous since pure individuals are

obtained instead of the mixtures of isomers which would be formed if anthraqui-

none were nitrated.

Aminopyridines are especially convenient as a starting material for the pre-

paration of nitropyridines by oxidizing the amino group. Kirpal and Böhm [214]

have obtained 2-nitro- and 4-nitro-pyridines by this method.

Among other oxidizing agents which can be used for the conversion of the

amino group to the nitroso and nitro group the following compounds should be

mentioned: peracetic acid (D’Ans and Kneip [215], Greenspan [216], Mosby and

Berry [213]), an aqueous solution of sodium peroxide (O. Fischer, Trost [217]),

and an acid solution of ammonium persulphate with addition of silver nitrate as

a catalyst (Witt and Kopetschni [218]).

Emmons [177] has recently suggested the oxidation of anilines to nitrobenzenes

by trifluoroperacetic acid (CF 3 .COOOH). He obtained high yields, for example:

TABLE 14

Substrate Product

Aniline

o- Nitroaniline

p- Nitroaniline

p- Phenylenediamine

p- Toluidine

2,4-Dinitroaniline

89% of nitrobenzene

92% of o- dinitrobenzene

94% of p- dinitrobenzene

86% of p- dinitrobenzene

78% of p- nitrotoluene

87% of 1,2,4-trinitrobcnzene

2,4,6-Tribromo- and -trichloro-aniline give nearly theoretical yields of 2,4,6-

tribromo- and -trichloro- 1- nitrobenzene (100% and 98% respectively).

The method of conversion of an amino into a nitro group has not found appli-

cation in the nitration of aliphatic amines, since only insignificant yields of nitroso

and nitro compounds could have been obtained together with considerable quan-

tities of oxidation products. For example, ethylamine, reacted with Caro’s acid,

yields, according to Bamberger [219], the following products: acetic acid, as the

principal product and along will1 it small quantities of nitroethane, acetohydro-
xamic acid, acetoxime and acetonitrile. If an amino group is attached to a tertiary

alkyl carbon, higher yields of nitroso compounds can be obtained. Thus, tert-butyl-

amine gives oxime in good yield, and then nitroso-tert-butane is obtained (Bam-
berger and Tschirner [220]).