THE NITROLYSIS OF HEXAMETHYLENETETRAMINE: I. THE SIGNIFICANCE OF 1,5-ENDOMETHYLENE-3,7-DINITRO-1,3,5,7-TETRAZACYCLOÖCTANE (DPT)

Abstract

The nitrolysis of hexamethylenetetramine by the method of Hale yields, in addition to Cyclonite, an aqueous diluate which contains either dimethylolnitramide, its dinitrate ester, or both. The presence of dimethylolnitramide can be demonstrated by its condensation with methylenediamine to give 1,5-dinitro-3,7-endomethy¡ene-1,3,5,7-tetrazacycloöctane (DPT). The latter compound was identified by nitrolysis to 1,3,5,7-tetranitro-1,3,5,7-tetrazacycloöctane. The validity of the Mannich-type condensation of dimethylolnitramide from the Hale diluate (or from formaldehyde and nitramide) to form DPT has been attested by similar condensations with methylamine, ethylenediamine, cyclohexylamine, and benzylamine. In one of these condensations acetaldehyde has replaced part of the formaldehyde. Dimethylolnitramide has further been characterized by its conversion to 3,7-dinitro-3,7-diaza-1,5-dioxacycloöctane. Nitrolysis of the latter forms sym. dinitroxydimethylnitramide, which can be acetolyzed to sym. diacetoxydimethylnitramide.

Solubility of 3,7-Dinitro-1,3,5,7-tetraazabicyclo [3.3.1] Nonane in Ethanenitrile, Methanol, 1,1-Dichloroethane, Dimethyl Sulfoxide, Acetone, and Mixed Solvents

“…3,7-Dinitro-1,3,5,7-tetraazabicyclo [3.3.1] nonane (DPT) is well-known as the key intermediate of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) synthesized from hexamethylenetetramine (HA) . HMX is one of the most powerful explosives and can be synthesized by nitrify DPT with nitric acid and nitrogen pentoxide (Figure ).…”

“…Its density is 1.63 g·cm –3 . Wright first synthesized DPT by sulfuric acid and methenamine dinitrate with 31 % yield in 1949 . After that, different synthetic schemes were reported to improve the procedure and the yield. , Along with the improvement of DPT synthesis, its purification also attracted considerable concerns .…”

Thermal Conductivity and Density of (NH4)2SO4 + H2O, NH4NO3 + H2O, and (NH4)2SO4 + NH4NO3 + H2O Solutions at T = (278.15 to 333.15) K

“…Aqueous solutions of ammonium sulfate + ammonium nitrate are widely synthesized not only in the production of ammonium sulfate-nitrate (ASN) fertilizers from effluent gases of thermal power plants containing a significant amount of sulfur dioxide and nitrogen oxides, but also in national defense industry and military engineering for the manufacturing of various energetic chemicals including 3,7-dinitro-1,3,5,7-tetraazabicyclo[3,3,1]nonane, , which is a key precursor to octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, one of the most powerful high explosives manufactured in bulk at present with high density, high energy, low sensitivity, and excellent performance. , Over the past century, various technologies have been proposed to prepare 3,7-dinitro-1,3,5,7-tetraazabicyclo[3,3,1]nonane. − The aldehyde-amine condensation method has shown great advantages because of its relatively simple process and low cost. In the procedure, nitrourea is first produced in situ without separation of the compound by nitration of urea in a mixture of 98 % nitric acid and oleum (20 % SO 3 ), and then hydrolysis of nitrourea to give nitramide in the presence of formaldehyde occurred through formation of N -dimethylol nitramide since the subsequent neutralization with ammonia obtained the desired product. ,,, During the neutralization process with ammonia, the aqueous phase includes moderate to high salt concentrations, and different portions of ammonium sulfate and ammonium nitrate at temperatures range from (280.15 to 313.15) K. Thus, reliable data and modeling on the thermodynamic and transport properties of the binary and ternary mixtures are needed over a wide range of concentrations and temperatures for the simulation and optimization of the synthetic process.…”

Modelling of the Effect of Concentrated Nitration Conditions on the Efficiency of the Production of 3,7-Dinitro-1,3,5,7-tetraazabicyclo[3,3,1]nonane (DPT)

“…Good solubility in low concentration mineral acids (precipitation at pH=3.4) [21]; Slightly soluble in organic solvents (e.g. in acetone) [21]; Practically insoluble in cold water, decomposed in hot water [24] …”