Hexyl = Hexanitrodiphenylamin

Thus, nitro compounds in a concentration as low as a few milligrams per litre are lethal to fish. Wastes from the manufacture of hexyl (hexanitrodiphenylamine) are particularly toxic, killing fish at a concentration as low as 0.1 mg of hexyl per litre. For this reason, the removal of these compounds from the waste water prior to its discharge is of primary importance. 

The high explosive known as hexyl (2,2, 4,4, 6,6 -hexanitrodiphenylamine) is synthesized in two steps from the nitration of 2,4-dinitrodiphenylamine. The first nitration uses 55 % nitric acid at elevated temperature for conversion to 2,2, 4,4 -tetranitrodiphenylamine. Introduction of two more nitro groups to yield hexyl requires a mixture of concentrated sulfuric and nitric acids, although the reaction can be conducted at room temperature (Section 4.8.1.3)." ... 

Picryl chloride (87) reacts with pyridine to form picrylpyridinium chloride (93), a useful intermediate which reacts with a range of nucleophiles 2,4,6-trinitrodiphenylamine and 2,4,6-trinitrodiphenylether can be formed from aniline and phenol respectively. 2,4,6-Trinitrodiphenylamine is readily nitrated with mixed acid to the high explosive 2,2, 4,4, 6,6 -hexanitrodiphenylamine (hexyl). 

During WWI Ger Whitehead torpedoes were loaded with Hexyl, which consisted of TNT 60 HNDPhA (Hexanitrodiphenylamine)... 

Apart from tetryl, which is discussed in the chapter on nitramines (Vol. Ill), the only aniline nitro derivative that has gained any considerable importance as an explosive is hexanitrodiphenylamine, or hexyl. None of the other nitro derivatives has proved of greater interest though some achieved temporary importance (as for example tetranitroaniline) or aroused a theoretical interest. 

Hexanitrodiphenylamine (m. p. 243-245°C) was first mentioned in the chemical literature in 1876 and as long ago as 1891 Haussermann [21] drew attention to its explosive properties. The product is known under the names of Dipicrylamine, Hexyl, Heksyl, Hexamite, Hexamin, etc. 

Gnehm [22] prepared hexanitrodiphenylamine by the nitration of diphenyl-amine with nitric acid, while Mertens [23] used a mixture of anhydrous nitric acid with concentrated sulphuric acid for the purpose. This method was applied in 1910 for the commercial preparation of hexyl. Since the yields obtained were too low (some 60% of the theoretical), during World War I a method patented in 1895 by the Griesheim Works was introduced, the starting materials being chlorodi-nitrobenzene and aniline. The method consists in the preparation of dinitrodi-phenylamine (m. p. 156-167°C) which is then nitrated in two stages, to obtain first tetranitrodiphenylamine (m. p. 199°C) and then hexyl ... 

Hexanitrodiphenylamine forms yellow needles, which decompose while melting. It is difficult to dissolve in concentrated sulphuric acid and in most organic solvents. It dissolves more easily in hot acetic acid, nitrobenzene and acetone. The pyridine salt of hexyl is still more readily soluble in acetone. 

SYNS AURANTIA BIS(2,4,6-TRINITRO-PHENYL)-AMIN (GERMAN) C.1.10360 DIPHENYLAMINE, HEXANITRO- DIPICRYLAMINE DIPICRYLAMINE (DOT) DIPIKRYLAMIN DPA ESANITRO-DIFENILAMINA (ITALIAN) 2,2, 4,4, 6,6 -HEXANITRO-DIFENYLAMIN HEXANITRODIFENYLAMINE (DUTCH) HEXANITRODIPHENYLAMINE HEXANITRODIPHENYLAMINE (FRENCH) 2,2, 4,4, 6,6 -HEXANTTRODIPHENYLAMINE 2,4,6,2, 4, 6 -HEXANTTRODIPHENYLAMINE HEXYL (GERMAN, DUTCH)... 

---