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NITRO DERIVATIVES OF HIGHER BENZENE HOMOLOGUES^415

NITRO-SOLVENT-NAPHTHA

Difficulties met in separating chemical individuals from higher fractions of

light oil and lower fractions of middle oil stimulated attempts at the direct nitra-
tion of solvent-naphtha, the name given to a mixture of isomers comprising

xylenes, ethylbenzene, pseudo-cumene (1,2,4-trimethylbenzene), ethyltoluene and

mesitylene.
The mixture is obtained as a fraction boiling within the range 120-175°C. lt

should be nitrated with great care, since it reacts violently with nitric and sulphuric

acids. Nitration techniques have been described in a number of patents (Dahmen

[31]; Blechner, Lopez and Distler [32]; Schultz [33]):

In most of the descriptions temperatures of 25-30°C are quoted for the first

nitration stage and 80°C towards the end of the process. The nitrating mixture is

prepared from concentrated sulphuric (sp. gr. 1.84) and nitric (sp. gr. 1.50)

acids.
The product is a mixture of oil with a solid substance, the quantity of the latter
depending on the fraction of solvent-naphtha used.
Thus, Blechner, Lopez and Distler [32] give the following data on the nitration
of various solvent-naphtha fractions (Table 93).

TABLE 93

Fraction boiling within Average yield

the temperature range, °C solid substance, % oily substance, %

140-145 80 20

150-155 40 60

160-165 100 -

For some time nitro-solvent-naphtha was a widely used component of explosive

compositions. Liquid fractions of the nitrated substance have also been used in the

manufacture of mining explosives and even of smokeless powder, as an explosive

solvent for nitrocellulose. In the latter case liquid nitro-solvent-naphtha acted

as a substitute for part of the nitroglycerine. This type of smokeless powder was

also manufactured in Poland in the period between the two World Wars (Karda-

szewicz, Markiewicz and Smisniewicz [34]).

HEXANITROSTILBENE