CZ302068B6 - Process for preparing cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole - Google Patents

Abstract

In the present invention, there is disclosed a process for preparing cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole by condensation of sulfamic acid salt, glyoxal and formaldehyde, followed by nitration of the obtained intermediate wherein first there is prepared the salt of octahydroimidazo-[4,5-d]imidazole-1,3,4,6-tetrasulfonic acid with an alkali metal or alkaline earth metal such that sulfamic acid salt is brought into reaction with an alkali metal or alkaline earth metal, glyoxal and formaldehyde in the following ratio: 1 mole sulfamic acid anion, 0.2 to 0.40 mole glyoxal and 0.40 to 0.60 mole formaldehyde in an aqueous medium containing 6 to 30 moles water per 1 mole of sulfamic acid anion, at a temperature ranging from 25 to 95 degC, for a period of 3 to 16 hours and at pH value of the reaction medium within the range of 3 to 6, whereupon the obtained salt of the octahydroimidazo-[4,5-d]imidazole-1,3,4,6-tetrasulfonic acid with alkali metal or alkaline earth metal is subjected after its isolation from the reaction mixture alone or in a mixture with urea and/or linear urea-formaldehyde condensates in an amount up to 2.5 percent by weight to a nitration and splitting by a nitrolyzing mixture containing nitric acid in an amount of 20 to 85 moles of nitric acid per 1 mole of octahydroimidazo-[4,5-d]imidazole-1,3,4,6-tetrasulfonic acid salt at a temperature ranging from -30 to +10 degC, whereupon the obtained product is isolated and optionally purified.

Description

Process for the preparation of cis-133, b-tetranitrooctahydroimidazo- [4,5-dimidazole

Technical field

The present invention relates to a process for the preparation of the polynitro compound cis-1,3,4,6-tetranitrooctahydroimidazo [4,5-d] imidazole (bicyclo-HMX, BCHMX).

BACKGROUND OF THE INVENTION

The target polynitroso compound, t75-1,3,4,6-tetranitrooctahydroimidazo- [4,5-d] imidazole (BCHMX), belongs to the group of polycyclic ni-trines and its use is predominantly used in explosive mixtures and propellants (Ling, Qiu Heming Xiao: Molecular dynamics study of binding energies, mechanical properties, and detonation performances of bicyclo-HMX-based PBXs, Journal of Hazardous Materials (2009), 164 (1), 329-336). The use of its mixture with 2,4,6-trinitrotoluene (TNT) for the production of fine synthetic diamonds has also been reported (Ultra Fine Diamonds, see Kozyrev NV, Sysolyatin SVm Sakovich GV: Preparation of Multifunctional Diamonds from TNT with Polycyclic Tram) Physics of Goreniva i Vzryva (2006), 42 (4), 131-134),

Interest in BCHMX culminated in the 1980s, when it was theoretically predicted that BCHMX performance should equal or even exceed 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (octogen , HMX). Published studies of the time and the present are concerned with the prediction of the properties of BCHMX and some of its mixtures, but also with its thermal stability and combustion.

Many attempts have been made to synthesize BCHMX. After many years of effort his first laboratory preparation has been published (Eck, Genevieve, Piteau, Marc: Preparation of 2,4,6,8-tetranitro2,4,6,8-tetraazabicyclo [3.3.0] octane; GB 2303849 (1997)) .

It starts from the tetraacetyl derivative octahydroimidazo- [4,5-d] imidazole as a precursor which is nitrated for 5 days at 10 ° C in acetonitrile using nitronium tetrafluoroborate as the nitrating agent and potassium fluoride as the catalyst; BCHMX was obtained in 20% yield. However, this must be isolated from the reaction mixture by subjecting the reaction mixture to hydrolysis, followed by filtration and concentration in vacuo. The disadvantage of this process is the high cost of the used nitrating agent, solvent and precursor, which itself is prepared from other raw materials by a three-step synthesis. Further disadvantages are the long reaction time, the method of product isolation and its low yield. The reported purity of BCHMX is 96%.

Another possibility for BCHMX synthesis is the nitrative cleavage of the octahydroimidazo [4,5-d] imidazole diacetyl dinitroderivative (Spear J., Dagley J .: Synthesis of Organic Energy Compounds, in: Marinkas J. (Ed.), Organic Energy Compounds, Nova Sci. Publishers, NY, 1996, pp. 47-164). It is nitrated with a nitrated mixture of reduced acidity (eg nitric acid-nitric oxide or nitric acid-phosphoric acid):

- 1 GB 302068 B6

n ₂ o ₅ / hno ₃ o ₂ n no ₂ o ₂ n no ₂

Although this nitration cleavage is easy to carry out and due to the stabilizing action of the two already present nitro groups, the reaction can be carried out even at slightly elevated temperatures, besides low yield, the main problem is the preparation of the starting compound:

Br

Br nhno nhno _{2 2}

In the preparation of these precursors, methylenedinitramine (MEDINA) must be used, which is very expensive and itself not very stable explosive. It is hygroscopic and forms salts having the properties of explosives; this and low stability makes it impossible to store and handle on an industrial scale from a safety point of view.

Recently, incomplete information on the preparation of cyclic nitramines with the potassium salt of sulfamic acid as one of the basic raw materials has been published and a scheme for the synthesis of BCHMX as well as a new precursor for its production, the tetrasodium octahydroimidazo [4,5- d] imidazole-1,3,4,6-tetrasulfone (K-TACOS) (Sysolyatin S, V., Sakovich GV, Chemikova Yu. T., Surmachev VN, Lobanova AA: Synthesis of polycyclic nitramines by nitration of condensation products of glyoxal and formaldehyde with sulfamic acid salts, in: 37 ^th Annual. Conference of ICT, Karlsruhe, 2006, pp. 141 / 1-141 / 12). Said tetrasodium salt (K-TACOS) is to be prepared by condensation of the potassium salt of sulfamic acid, glyoxal and formatdehyde in a certain ratio. According to the above scheme, K-TACOS should be nitratable with nitric acid on BCHMX:

HN ₂ SO ₃ K + o '

H7H ₂ O

KCLS SCLK ³ \ / ³

KO ₃ S ^Z S ₃ K

KO ₃ S SO ₃ K

However, the detailed description of the reaction scheme in the literature lacks any detailed information on the practical mode of its implementation, both for the preparation of octahydroimidazo [4,5d] imidazole-1,3,4,6-tetrasulfonic acid salts (M-TACOS) and BCHMX. . It is only mentioned that nitrolysis of K-TACOS with concentrated nitric acid takes place at -35 to -30 ° C in 60% yield. However, these temperatures are relatively unsuitable for industrial use, since providing the reaction mixture to such low temperatures is not easy and increases the technological and financial demands of the production.

-2EN 302068 Bo

The object of the present invention is to find the conditions for the practical synthesis of BCHMX and its intermediate, the salt of octahydroimidazo [4,5-d] imidazole-1,3,4,6-tetrasulfonic acid (M-TACOS) on the basis of the above schemes, preferably so that the synthesis can be carried out under more convenient conditions, especially at higher temperatures, as well as to identify critical reaction sites, as well as the most suitable method of purification of BCHMX.

SUMMARY OF THE INVENTION The present invention provides a process for the preparation of cis-1,3,4,6-teranitrooctahydroimidazo- [4,5-d] imidazole (BCHMX), comprising:

1) prepare the intermediate alkali metal or alkaline earth metal octahydroimidazo- [4,5-d] imidazole-1,3,4,6-tetrasulfonic acid salt (M-TACOS) by reacting the sulfamic acid salt with an alkali metal or alkaline earth metal, glyoxal and formaldehyde in a ratio of 1 mol of sulfamic acid anions, 0.20 to 0.40 mol of glyoxal and 0.40 to 0.60 mol of formaldehyde, preferably in a ratio of 1 mol of sulfamic acid anions, 0 25 to 0.32 moles of glyoxal and 0.48 to 0.53 moles of formaldehyde which react in an aqueous medium containing 6 to 50 moles of water per 1 mol of sulfamic acid anions, preferably 9.7 to 41.3 moles of water per mol 1 mol of sulfamic acid anions, at a temperature in the range of 25 to 95 ° C, preferably at a temperature in the range of 35 to 85 ° C, for 3 to 16 hours and at a pH of the reaction medium in the range of 3 to 6, octahydroimidazo- [4,5-d] imidazole-1,3,4,6-tetrasulfone with alkali metal or alkaline earth metal (MT ACOS) is isolated from the reaction mixture.

2) then the alkali metal or alkaline earth metal octahydroimidazo- [4,5-djimidazole-1,3,4,6-tetrasulfonic acid salt (M-TACOS), alone or in admixture with urea and / or linear urea-formaldehyde condensates in an amount of up to 2.5% by weight, nitrating the nitrol by starting with a mixture containing nitric acid in an amount in the range of 20 to 85 moles of nitric acid, preferably in the range of 34 to 79.91 moles of nitric acid, per 1 mol of acid salt octahydroimidazo- [4,5-d] imidazole-1,3,4,6-tetrasulfonic acid at temperatures ranging from -30 to + 10 ° C, whereupon the obtained BCHMX product is isolated and optionally purified.

The alkali metal or alkaline earth metal is preferably selected from the group consisting of potassium and barium.

The first step of the present invention, i.e. the preparation of octahydroimidazo [4,5-d] imidazole-1,3,4,6-tetrasulfonic acid (M-TACOS) salts, can be illustrated by the following reaction scheme. The isolation of M-TACOS then consists either in ethanol precipitation or the product precipitates from the reaction mixture spontaneously during the reaction after the starting materials have reacted.

-3 CZ 302068 B6

NH ₂ SO ₃ M +

O'

HH ⁺ / H ₂ O + 2) ^ OH with ₃ m sclm ³ \ / ³ <T>

i \ of ₃ m to ₃ m where: M is an alkali metal ~ .0

M (NH ₂ SO ₃ ) ₂ + h ⁺ / h ₂ °

O'

M ²⁺

where: M = alkaline earth metal

The interaction of glyoxal, formaldehyde and sulfamate as an acid-catalyzed nucleophilic addition takes place, due to the nature of the reactants, in a protic polar solvent, preferably in an aqueous environment. In particular, potassium sulfamate and barium sulfamate are poorly soluble in water at room temperature, but their solubility increases rapidly with increasing temperature. Glyoxal and formaldehyde are reacted in the form of their aqueous solutions. Because of the solubility of M-TACOS in water, the amount of water in the reaction mixture determines its yield and purity; there is a critical amount of water in the reaction mixture, beyond which the product cannot be separated from the reaction mixture and cannot be isolated in pure form.

The reaction temperature does not affect the yield of M-TACOS, but significantly affects the reaction time. The acidity of the reaction mixture is important for the purity of this salt: at too low a pH the product hydrolyzes, at high pH the corresponding salt of 1,3,5-triazinan-1,3,5-trisulfonic acid, salt of acid 2, is formed in addition to M-TACOS, 3,5,6-tetrahydroxypiperazine-1,4-disulfone and other compounds.

The present invention also provides a process for preparing M-TACOS in which the present aqueous solution of an alkali metal or alkaline earth metal sulfamate is heated to a temperature in the range of 25 to 95 ° C, preferably to a temperature in the range of 35 to 85 ° C, more preferably in the range of 35 to 60 ° C, most preferably at 35 to 55 ° C, with a mixture of aldehydes. The solution has an initial pH in the range of 5.5 to 6.0 (corrected for temperature). The pH of the reaction mixture decreases during the reaction, so that it is appropriate to adjust it continuously, for example by adding solid potassium bicarbonate so that it does not fall below 3.0. The mixture of aldehydes is prepared by mixing aqueous solutions of glyoxal (preferably 40%) and formaldehyde (preferably 37%) in a certain ratio. The ratio of sulfamate to aldehydes is not stoichiometric. Preferably a slight excess of the aldehyde mixture relative to the sulfamate is used. This is because the reaction is reversible and a slight excess of aldehydes shifts the equilibrium in the mixture of formation of the desired product and thus increases its yield. Also, the theoretical molar ratio of glyoxal to formaldehyde is preferably not used for the aldehyde mixture. The reason is higher reactivity of formaldehyde over glyoxal. The stoichiometric mixture of aldehydes would behave as a mixture with an excess of glyoxal over stoichiometry and formaldehyde would then preferentially react to the 1,3,5-triazinane-1,3,5-trisulfonic acid salt of the respective alkali or alkaline earth metal contaminating M-TACOS and, in addition to BCHMX, β, 3,5-trinitro-1,3,5-triazinane (RDX) would be present in the nitration product. For example, in the case of the synthesis of K-TACOS (potassium salt of octahydroimidazo- [4,5-d] imidazole-1,3,4,6-tetrasulfonic acid), the optimal molar ratio of potassium sulfamate to glyoxacformaldehyde is 3.125: 1: 1.656 and the optimal feed time of the aldehyde mixture to The stirred solution of potassium sulfamate is one hour. After the addition, the reaction mixture is stirred at a temperature of about 55 ° C for 5 hours. After this time the yield of the product is about 70% of theory. After stirring at this temperature for 9 hours, the reaction is virtually complete and the product yield exceeds 85% of theory. If reaction temperatures below

The reaction time to achieve a comparable yield is extended to 2-3 days. After cooling the reaction mixture to room temperature, the white precipitate of the product is suction filtered on a frit and washed with cold water and acetone, dried at temperatures not exceeding 60 ° C. The use of mother liquor after product filtration in a new reaction is not recommended because its chemical composition is variable and K-TACOS of low purity is formed.

A modified process for the preparation of M-TACOS consists in using a solution of an alkali metal or alkaline earth metal sulfamate in water of less than the critical concentration required to precipitate the ______________________________________. % of the product during the reaction. Using a solution with an initial concentration of less than 2.46 moles of dm sulfamate, the product is not precipitated and remains in solution. In this case, the mixture is cooled to -10 ° C and an equal volume of 96% ethanol is added with vigorous stirring. not recommended as it often produces "oily products" and M-TACOS cannot be isolated from the mixture). The precipitate formed is filtered off, washed with a little water and ethanol and dried. However, the product thus obtained contains a large amount of impurities (inter alia unreacted sulfamate), which is difficult to remove from M-TACOS. Contaminated M-TACOS then yields disproportionately lower BCHMX yields. For these reasons, it is preferable to use the M-TACOS synthesis method with a starting supercritical concentration of the sulfamic acid salt.

The advantage of the preparation of M-TACOS as an intermediate of the BCHMX synthesis according to the present invention is above all the low cost and easy availability of the starting materials and the absence of organic solvents in the production process. An indisputable advantage is also the easy isolation of M-TACOS and its relatively high chemical stability after good washing and drying as well as its easy handling (it does not sinter, it is not hygroscopic). Last but not least, a high process yield and thus a low final cost of this precursor is advantageous.

In the second step of the process of the present invention, the intermediate M-TACOS is internally cleaved by nitrous nitric acid mixture according to the following reaction scheme.

o ₂ n no ₂

wherein: M = alkali metal s; * so;

NO /

SIO ₂

>

<

no ₂ where M = alkaline earth metal

The nitrolysis mixture containing nitric acid may be selected from the group comprising nitric acid having a minimum concentration of 92% by weight, preferably a minimum concentration of 97.5% by weight. % and up to 0.50 wt. analytical nitric acid therein; and mixtures of nitric acid with a substance selected from the group consisting of phosphorous pentoxide, nitric oxide, sulfuric acid, sulfur trioxide, and an inert solvent such as dichloromethane.

-5GB 302068 B6

If a mixture of nitric acid and phosphorus pentoxide is used as the nitrolysis mixture, i.e. the source of the nitrating agent, the nitration cleavage is preferably carried out at a temperature in the range of -10 to +10 ° C.

If a nitric acid mixture, ie a source of nitrating agent, is a mixture of nitric acid and phosphorus pentoxide in the presence of an inert solvent such as dichloromethane, preferably the nitration digestion is carried out at a temperature between 0 and + 10 ° C and the product after separation. % of the inert solvent from the mixture, is preferably isolated by mixing the reaction mixture with crushed ice and filtering off the precipitate of the crude product from which the cis-1,3,4,6-tetranitrooctahydroimidazo [4,5-d] imidazole is preferably purified by acetone.

If a nitric acid mixture with an oleic concentration of 20 to 65% is used as the nitrolysis mixture, i.e. the source of the nitrating agent, the nitration digestion is preferably carried out at a temperature in the range of -30 to 0 ° C.

Nitrolysis of the TACOS salt (M-TACOS) to the BCHMX end product is feasible provided that the bicyclic backbone of the molecule is not cleaved in the reaction. This is achievable when the reaction is conducted at least initially in a nitrolysis medium with reduced acidity at temperatures up to max. 10 ° C, or in a nitrolysis environment with increased acidity at temperatures up to -20 ° C. The concentration of nitric acid used should be above 92% and should be used in approximately 20 to 85 times molar excess compared to theory, but preferably in 34 to 80 times molar excess. Mixtures of nitric acid with nitric oxide, phosphorus pentoxide and sulfuric acid with sulfuric acid may also be used.

The pre-dried and finely ground M-TACOS is used either neat or with up to 2.5% by weight of powdered urea or linear urea-formaldehyde condensate (preparation according to Zeman S., Lipka R., Ambroz F., Frederick F., Fedak J , Dimun M .: A method for producing urea-formaldehyde condensates, CS Pat. 227 901 (1983) and also DD Pat. 230 247 A3 (1985)); these admixtures serve as acceptors of nitrogen oxides, sources of amino groups and, in the case of urea-form of the Idehydde condensate, also a source of methylenamine grouping (all counteract the cleavage of azacyclic systems in nitration environment and thus increase nitrolysis yields - see Zeman S., Fedák J Dimun M .: 1,3,5-Trinitro-1,3,5-triazacyclohexane, CS 227905 (1986)) The powder mixture is then metered into the nitrolysis mixture to ensure perfect and rapid suspension in the nitrolysis mixture. (nitrating acid). Depending on the type of nitration mixture used, its ratio to the substrate to be introduced, and the reaction temperature, BCHMX may then precipitate during the reaction.

After the reaction, the BCHMX product is preferably isolated by mixing the reacted reaction mixture with crushed ice, filtering the suspension thus obtained, washing the filter cake with neutral water and drying, preferably at a temperature of about 60 ° C. Purification of the product is usually accomplished by recrystallization, preferably by dissolving the crude product from the reaction mixture in an organic solvent at 45-55 ° C to form a saturated solution from which the product precipitates by addition of ethanol and / or water. Preferably, the solution in the organic solvent is neutralized prior to precipitation by addition of an alkali metal bicarbonate to the neutral reaction of the solution.

Recrystallization of crude BCHMX can be carried out from any suitable solvent (acetone, dimethylsulfoxide, acetonitrile, ethyl acetate, etc.) - for solubility of BCHMX in organic solvents see Klasovitý D., Zeman S., Ruzicka A., Jungova M., Rohac M.: c / sl, 3,4,6-Tetranitrooctahydroimidazo [4,5-d] imidazole (BCHMX), its properties and initiation reactivity, J. Hazard. Mater. 164 (2009) 954-961). Acetone is best used to remove residual acid from the product. The crude BCHMX was dissolved therein (to 10 g BCHMX 60 ml acetone) and then added with stirring enough alkali metal bicarbonate until the solution showed a neutral to slightly basic reaction. The mixture is stirred for an additional 10 minutes and then poured into 5 times cold water while stirring and the product is collected by filtration on a frit, washed with ethanol or diethyl ether and dried. You can also proceed by adding to the hot blended

A solution of BCHMX in acetone was added to approximately equivalent volume of ethanol, and then water was added until the cloudiness persisted, the mixture was allowed to cool with stirring, and then the product was collected by filtration. According to the method of carrying out the reaction, yields of BCHMX of from 15 to 68% compared to the theory calculated on the recrystallized product and the precursor M-TACOS can be achieved.

The nitration cleavage of M-TACOS proceeds easily because the sulfo group attached to the aza-atom of the organic backbone is readily replaceable by the nitro group. Therefore, the reaction proceeds faster compared to similar acetyl derivatives used in previously published BCHMX synthesis procedures. Another advantage of this cleavage is its relatively high safety, where in the case of insufficient mixing of the mixture or local overheating, the reaction mixture does not burn (as is the case with W-saltz nitration on RDX), but only its foaming and slow development of other gases. The ecological nature of the process is another advantage, since the stable by-product of the production after acid recovery is mainly alkali metal or alkaline earth metal hydrogen sulphate (or alkali metal or alkaline earth metal phosphates using the nitric acid-phosphorus pentoxide system).

The present invention provides suitable reaction conditions (forms of the starting materials, their reaction ratio, concentration, temperature, reaction time, pH of the mixtures, etc.) as for the condensation of the raw materials to the octahydroimidazo [4,5-d] imidazole-1 acid salt, 3,4,6-ethersulfonic acid (M-TACOS),

2o for its nitration to its own final BCHMX product, including its purification, leading to higher yields and allowing reactions to be carried out under conditions more favorable to the industrial production of BCHMX, in particular at higher temperatures than in the prior art, possibly with acid with lower concentrations than usual in the art.

DETAILED DESCRIPTION OF THE INVENTION

Example 1: Preparation of the K-TACOS intermediate (octahydroimidazo [4,530 d] imidazole-1,3,4,6-tetrasulfonic acid potassium salt)

To the present solution of 20.0 g of potassium sulfamate (0.152 mol) in 60 ml of water (3.33 mol) heated to 35 ° C, a mixture of 6.6 g of a 40% aqueous solution of gtyoxal (0.046 mol) was added over one hour. glyoxal and 0.22 mol of water) and 6.0 g of a 37% aqueous solution of formaldehyde (0.074 mol of formaldehyde and 0.21 mol of water), maintaining the pH in the range of 4.6 to 5.3 with potassium bicarbonate. After the addition, the reaction mixture is stirred for 4 hours at 35 ° C. K-TACOS is precipitated from the reaction mixture subcooled to -10 ° C by addition of 100 ml of acetone or an equal amount of 96% ethanol. After filtering the mixture, wash the K-TACOS with 30 mL of ice water and 50 mL of acetone. Drying gave 17.3 g of crude K-TACOS (79.6% of theory, calculated on potassium sulfamate). The product contains impurities, it is yellowish in color. In nitrolysis, it yields lower yields of BCHMX, heavily polluted RDX.

Example 2: Preparation of intermediate K-TACOS

A saturated solution of 135.1 g of potassium sulfamate (1 mol) in 120 ml of water (6.660 mol) was prepared and heated to 55 ° C. At a given temperature, the initial pH of the solution is adjusted to 5.5-6.0 with powdered potassium bicarbonate. An aldehyde mixture containing 47.5 g of a 40% aqueous solution of glyoxal (0.32 mol of glyoxal and 1.582 mol of water) and 43.5 g of a 37% aqueous solution of formaldehyde (0.53 mol of formaldehyde and 1.521 mol of water). At the end of the dosing, a white K-TACOS precipitate began to precipitate from the solution. The reaction mixture is then stirred for 7 to 9 hours at a temperature of about 50 ° C. If a lower temperature is used for post-reaction, the post-reaction time must be extended accordingly. Throughout the reaction, it is necessary to prevent a possible drop in the pH of the mixture below 3.0, which is achieved by the addition of powdered alkali metal bicarbonate. After completion of the reaction, the contents were

The reaction vessel was cooled to room temperature and the precipitate was filtered off, washed with 100 ml of ice-water, 200 ml of acetone and dried at a temperature below 50 ° C. The yield of K-TACOS is 123 g, or 84.2% of theory (calculated on the starting potassium sulphate). By using differential thermal analysis on a DTA 550 Ex instrument from OZM Research (Hrochův Týnec, Czech Republic) for thermal analysis of explosives, working with 50 mg sample weight and a linear temperature rise rate of 5 ° C min ¹ , the beginning of the endo-change 90.8 ° C and the onset of exothermic decomposition at 134.6 ° C.

Example 3: Preparation of K-TACOS intermediate

The procedure is as in Example 2 except that the initial temperature of the potassium sulfamate is 80 ° C, the aldehyde mixture is metered in for 30 minutes, and the reaction mixture is stirred for 3 to 5 hours at 80 to 85 ° C. Isolation and drying of the resulting product gave 18 g of crude K-TACOS (82.8% of theory, calculated on potassium sulfamate). By means of differential thermal analysis as in Example 2 (linear temperature rise rate of 5 ° C min ^-1 ), an onset of endo-change at 91.2 ° C and onset of exothermic decomposition at 135.1 ° C was found for this product.

Example 4: Preparation of the intermediate Ba-TACOS

A saturated solution of 90.0 g of barium sulfamate (0.273 mol) in 200 ml of water (11.10 mol) was prepared and heated to 60 ° C. Undissolved impurities (eg, barium carbonate) are filtered off while hot. At a given temperature, the initial pH of the solution is adjusted to 5.5-6.0 with barium hydroxide octahydrate powder. An aldehyde mixture containing 20.0 g of a 40% aqueous solution of glyoxal (0.135 mol of glyoxal and 0.666 mol of water) and 21.7 g of a 37% aqueous solution of formaldehyde (0.264 mol of formaldehyde and 0.758 mol of water) is then metered into the solution for ten minutes. . 30 minutes after the end of dosing, a white Ba-TACOS precipitate began to precipitate from the solution. The reaction mixture was then stirred for 16 hours at room temperature and pH above 3.0. After completion of the reaction, the contents of the reaction vessel are subjected to filtration and the precipitate formed is washed with 100 ml of hot water, 200 ml of acetone and dried at a temperature below 50 ° C. The yield of Ba-TACOS is 35.3 g (36.7% of theory, calculated on the starting sulfamate). By means of differential thermal analysis as in Example 2, an onset of exothermic decomposition was found at 124.8 ° C (no endo-change was observed). For a theoretical content of 6.81% C, 0.85% H and 7.94% N, 8.04% C, 0.94% H and 7.61% N were analyzed by Ba-TACOS.

Example 5: Preparation of BCHMX by nitrolysis of K-TACOS with nitric acid alone

A beaker equipped with a powerful mechanical stirrer, external cooling and thermometer was charged with 40 mL (0.933 mol) of nitric acid and cooled to -20 ° C. The reaction used was 97.5% nitric acid containing 0.5% analytical nitrous acid (i.e. a significant amount of nitrogen oxides). K-TACOS powder (10.0 g, 0.017 mol) was then slowly added to the acid with good stirring and continued cooling to -20 ° C. Dosage lasts

5 minutes. After the addition, the contents of the beaker were mixed for a further 5 minutes and the suspension thus formed

BCHMX in nitric acid is poured onto crushed ice. The precipitated acid product is filtered off, washed with water to neutrality, overlaid with diethyl ether and filtered off with suction. After drying at 50-55 ° C and recrystallization from acetone, BCHMX results in 24% of theory (calculated on K-TACOS).

Example 6: Preparation of BCHMX by nitrolysis of K-TACOS with nitric acid alone

A beaker equipped with a powerful mechanical stirrer, external cooling and thermometer was charged with 40 ml (0.933 mol) of nitric acid and cooled to -30 ° C with stirring.

The reaction used was 97.5% nitric acid containing 0.5% analytical nitric acid (i.e. a significant amount of nitrogen oxides). A powder mixture of 10.0 g K-TACOS (0.017 mol) and 0.1 g urea (0.0016 mol) was metered into the acid at -30 ° C over 20 minutes. After delivery, the contents of the beaker in the form of a yellowish clear solution are immediately poured onto crushed ice. The product is filtered off with suction, washed with water to neutrality and overlaid with diethyl ether. After drying at 50-60 ° C and recrystallization from acetone, 48% of BCHMX theory (calculated on K-TACOS) resulted.

Example 7: Preparation of BCHMX by nitrolysis of K-TACOS with nitric acid alone

A beaker equipped with a powerful mechanical stirrer, external cooling and thermometer was charged with 40 ml (0.933 mol) of nitric acid and cooled to -30 ° C with stirring. The reaction used was 97.5% nitric acid containing 0.5% analytical nitrous acid (i.e. a significant amount of nitrogen oxides). 10 g of K-TACOS powder (0.017 mol) was added to the acid at -30 ° C over 10 minutes. After the addition, the contents of the beaker were stirred for 10 minutes while allowing the temperature to rise freely to -10 ° C. The mixture starts to foam a little. Then, the suspension in the beaker is poured onto crushed ice, the product is filtered off, washed with water to neutrality and overlaid with diethyl ether. After aspiration and drying, the yield of BCHMX is about 48% of theory (calculated on K-TACOS).

Example 8: Preparation of BCHMX by nitrolysis of K-TACOS with nitric acid alone

To a 10 ml reactor equipped with a stirrer, external cooling and thermometer, nitric acid is continuously fed at a rate of 0.05 ml s ¹ (1.166 mmol s ^-1 ) and the K-TACOS powder is introduced at a rate of 0.02 g s ¹ (0.034 s ^_I mmol). The reaction used was 97.5% nitric acid containing 0.5% analytical nitrous acid (i.e. a significant amount of nitrogen oxides). The reactor is maintained at -30 to -35 ° C with vigorous stirring. The detention is 3 minutes. From this reactor, the contents continuously overflow into a second stirred reactor with a working volume of 50 ml, which is not cooled and the temperature in it does not exceed -10 ° C. From the second reactor, the reaction mixture flows continuously to stirred ice, where crude BCHMX is precipitated. Of the total 45 minutes of the reaction, the last 20 minutes of the reaction are for the recovery, of which the yield of BCHMX after its crystallization from acetone is 68% of theory (calculated on K-TACOS).

Example 9: Preparation of BCHMX by nitrolysis of K-TACOS with nitric acid alone

A beaker equipped with a powerful mechanical stirrer, external cooling and thermometer was charged with 35 mL (0.828 mol) of nitric acid and cooled to -30 ° C with stirring. The reaction used was 92% nitric acid containing 0.5% analytical nitrous acid (a significant amount of nitrogen oxides). 10.0 g of K-TACOS powder (0.017 mol) was metered into this acid at -30 ° C over 5 minutes. After the addition, the beaker contents were stirred at -25 ° C to -30 ° C for 5 minutes. Then the clear reaction mixture is poured into ice blast in a beaker, the product is filtered off, washed with water to neutrality, overlaid with diethyl ether and filtered off with suction. After aspiration and drying, the yield of BCHMX is about 12.4% of theory (calculated on K-TACOS).

Example 10: Preparation of BCHMX by nitrolysis of K-TACOS with a nitric acid-phosphorus pentoxide mixture

A beaker equipped with a mechanical stirrer, external cooling and a thermometer was charged with a mixture prepared by dissolving 11 g of phosphorus pentoxide (0.077 mol) in 55 ml (1.329 mol) of nitric acid, which was cooled to 0 ° C. Nitric acid, freshly concentrated by distillation in the presence of sulfuric acid having a concentration of 99.5% and an analytical nitric acid content below 0.03% by weight, was used. In this type of K-TACOS nitrolysis, the viscosity of the reaction mixture, which affects the rate of suspension of the precursor therein, is critical. If the ratio of nitration mixture to

-9EN 302068 B6

K-TACOS becomes too viscous when BCHMX is excreted from the reaction mixture and overheats locally to decompose the product. In this case, it is a low-acidity nitration mixture which allows tolerance to relatively high reaction temperatures. Thereafter, 20 g (0.034 mol) of K-TACOS powder was introduced into the beaker with the nitrolysis mixture under stirring for 10 minutes. During dosing, BCHMX is excreted from the mixture, which thickens and is stirred for a further 5 minutes. It is then poured onto crushed ice and the product precipitate is filtered off, washed with water until neutral, overlaid with diethyl ether and filtered off with suction again. After drying, 15% of the theory of BCHMX (calculated on K-TACOS) is obtained.

Example 11: Preparation of BCHMX by nitrolysis of K-TACOS with a nitric acid-phosphorus pentoxide mixture

In a beaker equipped with a mechanical stirrer, external cooling and a thermometer was added a mixture prepared by dissolving 30 g (0.21 mol) of phosphorus pentoxide in 80 ml (1.937 mol) of nitric acid, which was cooled to -5 ° C. Nitric acid, freshly concentrated by distillation in the presence of sulfuric acid having a concentration of 99.5% and an analytical nitric acid content below 0.03% by weight, was used. While stirring, 20 g (0.034 mol) of powdered K-TACOS containing 0.2 g (ca 0.0027 mol) of linear urea-formaldehyde condensate are metered into the beaker for 15 minutes. The resulting BCHMX suspension was stirred for 30 minutes at temperatures up to 5 ° C, then poured onto ice, the precipitated product was filtered off, washed with water until neutral, overlaid with diethyl ether and suction filtered again. After drying, 55% of the theory of BCHMX (calculated on K-TACOS) is obtained.

Example 12: Preparation of BCHMX by nitrolysis of K-TACOS with nitric acid-phosphorus pentoxide dichloromethane

A beaker equipped with a mechanical stirrer, external cooling and a thermometer was charged with a mixture of 50 ml (1.199 mol) of nitric acid containing 10 g (0.070 mol) of phosphorus pentoxide. Nitric acid, freshly concentrated by distillation in the presence of sulfuric acid having a concentration of 99.5% and an analytical nitric acid content below 0.03% by weight, was used. After cooling the mixture to 0 [deg.] C., 50 ml of dichloromethane are added thereto, and a powder mixture of 20 g (0.034 mol) of K-TACOS and 0.2 g (ca 0.0027 mol) of linear urea-formaldehyde condensate is metered in with vigorous stirring for 10 minutes. . The reason for using an inert solvent (dichloromethane) in the nitration mixture is to reduce the viscosity of the reaction mixture and to improve the heat circuit of exothermic nitrolysis K-TACOS. The mixture was then stirred for an additional 5 minutes at 10 ° C. After stopping the stirring, the dichloromethane layer was separated from the mixture and the remaining suspension was poured onto ice spray. The precipitated BCHMX precipitate was filtered off, washed with water until neutral and finally with diethyl ether. After drying, BCHMX results in a yield of 30% compared to theory calculated on K-TACOS.

Example 13: Preparation of BCHMX by nitrolysis of K-TACOS with a nitric acid-phosphorus pentoxide mixture of dichloromethane

A beaker equipped with a mechanical stirrer, external cooling and a thermometer was charged with a mixture of 100 ml (2.388 mol) of nitric acid containing 20 g (0.140 mol) of phosphoric pentoxide. Nitric acid, freshly concentrated by distillation in the presence of sulfuric acid having a concentration of 99.5% and an analytical nitric acid content below 0.03% by weight, was used. After cooling the mixture to 0 [deg.] C., 50 ml of dichloromethane are added and a powder mixture of 20 g (0.034 mol) of K-TACOS and 0.2 g (ca 0.0027 mol) of linear urea-formaldehyde condensate is metered in with vigorous stirring for 30 minutes. The mixture was then stirred for an additional 20 minutes at 10 ° C. After stirring was stopped, the dichloromethane layer was separated from the mixture and the clear reaction mixture was poured onto ice spray. The precipitated BCHMX precipitate was filtered off, washed with water until neutral and finally with diethyl ether. After drying, BCHMX resulted in a yield of 52.4% of theory, calculated on K-TACOS.

- 10GB 302068 B6

Example 14: Preparation of BCHMX by nitrolysis of K-TACOS with a mixture of nitric acid-phosphorus pentoxide dichloromethane

A beaker equipped with a mechanical stirrer, external cooling and a thermometer is charged with 70 ml (1.678 mol) of nitric acid containing 30 g (0.210 mol) of phosphorus pentoxide. Nitric acid, freshly concentrated by distillation in the presence of sulfuric acid having a concentration of 99.5% and an analytical nitric acid content below 0.03% by weight, was used. After cooling the mixture to 0 [deg.] C., 100 ml of dichloromethane are added thereto, and a powder mixture of 20 g (0.034 mol) of K-TACOS and 0.2 g (ca 0.0027 mol) of linear urea-formaldehyde is metered in with vigorous stirring for 5 minutes. condensate. The mixture was then stirred for an additional 35 minutes at 0 ° C. After stirring was stopped, the dichloromethane layer was separated from the mixture and the remaining suspension was poured onto ice spray. The precipitated BCHMX precipitate forms a sticky mass with water and residual dichloromethane. After suctioning off the liquid, this is dissolved in a minimum amount of acetone and the acetone solution is then poured into water. The precipitated BCHMX is filtered off, washed with water until neutral and finally with diethyl ether. After drying, BCHMX results in a yield of 60% compared to theory calculated on K-TACOS.

Example 15: Preparation of BCHMX by nitrolysis of K-TACOS with Nitric Acid Sulfuric Acid 20 Sulfur Oxide

In a beaker equipped with a mechanical stirrer, external cooling and a thermometer, 40 ml (0.959 mol) of nitric acid and 10 ml of 65% oleate are added. The reaction used was 97.5% nitric acid containing 0.5% analytical nitrous acid (i.e. a significant amount of nitrogen oxides). These are nitration mixtures with increased acidity and therefore low reaction temperatures cannot be avoided during K-TACOS nitrolysis. After the mixture was cooled to -30 ° C, 7.0 g (0.012 mol) of K-TACOS powder was charged into the mixture under vigorous stirring for 10 minutes. The mixture was then stirred for an additional 30 minutes at -30 ° C, after which time the temperature of the reaction mixture was allowed to slowly rise to 0 ° C (it takes about an hour). The resulting suspension is then poured onto ice spray, the precipitated BCHMX is filtered off, washed with water until neutral and finally with diethyl ether. After drying, BCHMX results in a yield of 28.6% compared to the theory calculated on K-TACOS.

Example 16: Preparation of BCHMX by nitrolysis of K-TACOS with nitric acid-sulfuric acid35 sulfuric trioxide

A beaker equipped with a mechanical stirrer, external cooling and a thermometer was charged with 440 mL (10.657 mol) of nitric acid and 110 mL of 65%. The reaction used was 97.5% nitric acid containing 0.5% analytical nitrous acid (i.e. a significant amount of nitrogen oxides). After cooling to -30 [deg.] C., 110 g (0.187 mol) of K-TACOS powder are charged into the mixture with vigorous stirring for 5 minutes. The mixture was then stirred for an additional 15 minutes at -30 ° C. The resulting suspension is then poured onto ice spray, the precipitated BCHMX is filtered off, washed with water until neutral and finally with diethyl ether. After drying, BCHMX results in a yield of 50% of theory, calculated on K-TACOS.

Example 17: Preparation of BCHMX by nitrolysis of Ba-TACOS with nitric acid alone

A beaker equipped with a powerful mechanical stirrer, external cooling and a thermometer was charged with 30 ml (0.699 mol) of nitric acid and cooled to -30 ° C. The reaction used was 97.5% nitric acid containing 0.5% analytical nitrous acid (i.e. a significant amount of nitrogen oxides). Ba-TACOS powder (10.0 g, 0.014 mol) was then slowly added to the acid with good stirring and continued cooling to -30 ° C. Dosing takes 5 minutes. After the addition, the contents of the beaker were stirred for an additional 16 hours at -20 ° C and then the resulting suspension in nitric acid was poured onto ice spray. Precipitated precipitate containing product

And barium bisulfate is filtered off, washed with water to neutrality and dried. The BCHMX is then extracted with 100 ml of acetone and the insoluble barium bisulfate is filtered off. The BCHMX is then precipitated from the acetone solution with water, sucked off on a frit, overlaid with diethyl ether and sucked off again. After drying at 50-55 ° C, 1.8 g of BCHMX (43.2% of theory, calculated on Ba-TACOS) resulted.

Example 18: Purification of crude BCHMX

When nitrolysis of K-TACOS using nitric acid alone is used for the production of BCHMX, the by-products contained in the crude BCHMX may also be brown resinous compounds with the aroma resembling nitric acid esters. These resins are well soluble in ethanol, in which BCHMX does not dissolve. The most economically available solvent for BCXHMX purification and recrystallization is acetone, the anti-solvent ethanol and water.

100 g of the beige color crude product of Example 6 was dissolved in 400 ml of hot acetone, the solution was diluted with 300 ml of ethanol and 300 ml of deionized water was added with stirring. After stirring for one hour, the suspension was filtered, the white product on the filter was washed with 30 ml of ethanol and dried. The onset of thermal decomposition of this BCHMX was at 226 ° C (by differential thermal analysis as in Example 2) and the crude product at 214 ° C.

Example 19: Purification of crude BCHMX

Crude BCHMX was dissolved in acetone (per 10 g BCHMX 60 mL acetone) and then added with stirring until enough alkali bicarbonate was added until the solution showed a neutral to slightly basic reaction. The mixture is stirred for a further 10 minutes and then poured into 5 times cold water while stirring, the product is collected by filtration, the filter cake is washed with ethanol or diethyl ether and dried.

Industrial applicability

The invention is useful for the preparation of a cis, 3,4,6-tetranitrooctahydroimidazo [4,5-b] imidazole (bicyclo-HMX, BCHMX) explosive and intermediates thereof, alkali metal or alkaline earth metal salts of octahydroimidazo [ 4,5-d] imidazole-1,3,4,6-tetrasulfone (M-TACOS).

Claims (5)

A process for the preparation of cis-1,3,4,6-tetranitrooctahydroimidazo [4,5-djimidazole, characterized in that: 1) an alkali metal or alkaline earth metal octahydroimidazo- [4,5-d] imidazole-1,3,4,6-tetrasulfonic acid salt is prepared by reacting the sulfamic acid salt 50 with an alkali metal or alkaline earth metal, glyoxal and formaldehyde in a ratio of 1 mole of sulfamic acid anion, 0.20 to 0.40 mole of glyoxal and 0.40 to 0.60 mole of formaldehyde, preferably in a ratio of 1 mole of sulfamic acid anion 0.25 to 0.32 moles of glyoxal and 0.48 to 0.53 moles of formaldehyde which are reacted in an aqueous medium containing 6 to 50 moles of water per 1 mol of sulfamic acid anion, preferably 9.7 to 41.3 moles water per mole of acid anion % Sulfamic, at a temperature in the range of 25 to 95 ° C, preferably at a temperature in the range of 35 to 85 ° C, po - 12EN 302068 B6 for a period of from 3 to 16 hours and at a pH of the reaction medium in the range of 3 to 6, whereupon the resulting octahydroimidazo- [4,5-d] imidazole-1,3,4,6-tetrasulfonic acid salt with an alkali metal, or isolates the alkaline earth metal from the reaction mixture, The method of claim 1, wherein the alkali metal or alkaline earth metal is selected from the group consisting of potassium and barium, 2) then the alkali metal or alkaline earth metal octahydroimidazo- [4,5-d] imidazole-1,3,4,6-tetrasulfonic acid salt alone or in admixture with urea and / or linear urea-formaldehyde condensates in an amount to 2.5% by weight, subjecting nitration digestion with a nitrolysis mixture containing nitric acid in an amount in the range of 20 to 85 moles of nitric acid, preferably in the range of 34 to 79.91 moles of nitric acid, per 1 mol of octahydroimidazo [4] salt. 5-d] imidazole-1,3,4,6-tetrasulfone at temperatures ranging from -30 to + 10 ° C, whereupon the product obtained is isolated and optionally purified. Method according to claim 1 or 2, characterized in that the nitrolysis mixture containing nitric acid is selected from the group comprising nitric acid having a minimum concentration of 92% by weight, preferably a minimum concentration of 97.5% by weight, and a content of up to 0%. 50 wt. analytical nitrous acid, mixtures of nitric acid with a substance selected from the group consisting of phosphorous pentoxide, nitric oxide, sulfuric acid, sulfur trioxide and an inert solvent, which is preferably dichloromethane. Process according to any one of claims 1 to 3, characterized in that the product is isolated by mixing the reacted reaction mixture with crushed ice, the suspension thus obtained is filtered, the filter cake is washed with water until neutral and dried. Process according to any one of claims 1 to 4, characterized in that the purification of the product is carried out by dissolving the crude product after isolation from the reaction mixture in an organic solvent, preferably selected from acetone, dimethylsulfoxide, acetonitrile and ethyl acetate, at 45 ° C. to 55 ° C to form a saturated solution from which the product precipitates by the addition of ethanol and / or water, preferably the solution in the organic solvent is neutralized by the addition of an alkali metal bicarbonate to the neutral reaction of the solution before precipitation.