urbaf2

NITRO DERIVATIVES OF ANILINE 569

Then the whole is heated to 60°C which initiates a further spontaneous tempera-

ture rise. Care should be taken by cooling to prevent the temperature rising

above 95°C, otherwise the yield might decrease. The process in nitrator 11, includ-

ing the transfer of contents from nitrator I, takes approximately 8 hours.

Half the contents of nitrator II is then transferred to a tank with 6000 1. of

water, a temperature of it below 50°C being maintained. This operation requires

from 4 to 6 hr, and when the tank has been discharged, the second half of the con-

tents of nitrator I1 is treated in the same way.

The precipitated product is filtered off and washed with water warmed to a tem-

perature not exceeding 50°C. Since moist tetranitrocarbazole is thixotropic the

filtration and washing is rather difficult to effect. The moist product is mixed in

a tank with a concentrated solution of 20 kg of sodium carbonate to deacidify it,

then filtered off and dried.

The product meets the following specifications:

melting point 281-290°C

sulphur content 0.8-1.3%

moisture 1-2%

nitrogen content 18.5-19.5% (theoretical 20.2%)

PREPARATION OF 1,2,6,8-TETRANITROCARBAZOLE

According to Murphy, Schwartz, Picard and Kaufman [34], 50 parts of carba-

zole is dissolved in 300 parts of 30% oleum at a temperature of 40-50°C. The

mixture is kept at 90-100°C for 2 hr. A sample of the mixture taken after

this time should dissolve completely in water. Then the mixture is cooled and 160

parts of 93% nitric acid are added, the temperature being maintained at

40-60°C. 1,2,6,8-Tetranitrocarbazole precipitates, and may be recrystallized

from nitrobenzene solution. The 1,3,6,8-isomer remains in the solution.

AMIDE DERIVATIVES OF TRINITROANILINES

Several rather simple acid amides have been tested as explosives. However,

they have not found practical used since they readily undergo hydrolysis.

HEXANITRODIPHENYLUREA