urbaf2

416 CHEMISTRY AND TECHNOLOGY OF EXPLOSIVES

Pure hexanitrostilbene (m. p. 211°C, with decomposition) was obtained by

S. Reich, Wetter and Widmer [35] by treating boiling trinitrobenzyl bromide with

alcoholic potassium hydroxide:

(5)

NITRO DERIVATIVES OF DIPHENYL

Diphenyl is nitrated with nitric acid in the presence of acetic acid to form a mix-

ture of mononitro derivatives:

2-Nitrodiphenyl 4-Nitrodiphenyl

m. p. 37°C m. p. 114°C

By boiling with nitric acid (98%) or with a mixture of nitric (77%) and sulphuric

acids, diphenyl yields a mixture of 2,4’- and 4,4’-dinitrodiphenyl:

m. p. 93-94°C m. p. 233°C

By direct nitration no more than four nitro groups can be introduced into di-

phenyl, 2,4,2’,4’-tetranitrodiphenyl being formed (Losanitsch [36]; Ulhnann and

Bielecki [37]).

m. p. 163°C

Nowadays the compound is not used in the explosives industry since its explo-

sive power is only slightly higher than that of dinitrobenzene, while on the other

hand its melting point is too high, and diphenyl, the raw material for its manufac-

ture, is available only in small quantities.