CS223661B1 - Production method of 1,4-dinitro-tetrahydroimidazo [4,5-d] imidazole-2,5 (1H, 3H) -dione - Google Patents

Abstract

The invention relates to the production of 1,4-dinitro-retra-hydroimidazo[4,5-d]-imidazol-2,5 (1H, 3H)-dione by nitration of tetrahydroimidazo[4,5-d]-imidazol-2,5 (1H, 3H)-dione in nitric acid, whereby the nitration conditions are selected in the presence of urea, which results in an increase in the yield and safety of the process. The invention can be used without problems in the production of the title substance.

Description

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The invention relates to the preparation of 1,4-dinitroderating tetrahydroimidazo [4,5-d] imidazole-2,5- (1H, 3H) -dione by nitration of tetrahydroimidazo [4,5-d] imidazole-2,5 (1H, 3H) -dione in the nitric acid medium, being chosen so as to favorably influence the yield and process safety.

The dinitroderivatives of tetrahydroimidazo [4,5-d] imidazole-2,5 (1H, 3H) -dione also known by the subtitle dinitroglycolurils denoted DINGU can be obtained by nitrating in the nitric acid and / or nitric acid medium in the acetic anhydride medium . The first mentioned variant is referred to as 1,4-; 1,6-; and 1,3-dinitroderivatives (En cyclopedia of Explosives and Related Items. Vol. 6, PATR 2700, Picatinny Arsenal, Dover, 1974, pp. G 117-118). 1,3-dinitroglycol-1 is unstable and readily decomposes in boiling water, allowing for a suitable choice of the method of isolating the nitration product of the glycoluril in the nitric acid medium, with the possibility of obtaining a high-1,4-isomer mixture of isomers predominantly. dinitroglycoluril, and non-1,3-dinitroglycoluril-containing functionalities. The yield of dinitroglycolurils resulted in general dependence on the reaction conditions due to the stability of glycoluril, i.e. 2,4,6,8-tetraazalbicyclo [3.3.0] octane glass in the reaction medium. In the nitric acid environment, acidolysis of glycoluril, which to some extent can be suppressed by the addition of a substance capable of exiting the reaction products in acidolytic equilibrium reactions, is the dominant side reaction.

According to the present invention, the process for the preparation of 1,4-dinitro-tetrahydroimidazo [4,5-d] imidazole-2,5 (1H, 3H) -dione by nitration of tetrahydroimidazo [4,5-d] imidazole- The 2.5 (1H, 3H) -dione in the nitric acid medium is carried out in that the nitration process takes place in the presence of urea added to the nitration system at one time or successively in an amount of 0.05 to 15% by weight, preferably 0.4 to 11% by weight. % Wt. % of the tetrahydroimidazo [4,5-d] -imidazole-2,5- (1H, 3H-dione) reaction. The advantage of the process according to the invention is that the presence of urea in the reaction mixture The optimum content of urea added to nitric acid prior to nitration is 1.1 to 1.7% by weight for the weight of glycoluril.Positive but less pronounced effect of the dinitroglycoluril feedstock it also has urea introduced into the reaction system as an additive of applied glycoluril.

As a result of this economic effect, it is an advantage of the present invention to increase the stability of the reaction mixture and hence the safety of the process due to the presence of urea. The stabilizing effect of urea in nitroses in the nitric acid medium (U.S. Pat. No. 97100, MS Author No. 227 903) or by esterification of aliphatic nitric acid or nitric acid with sulfuric acid (U.S. Pat. No. 168,189) is well known , as well as well interpreted in the works of V. Ka-deřábek and J. Denkstein: Coll. Czech. Chem.Comun. 1960, 25, 1070; or also MS. Authorized Certificate No. 227 903.

The novel and superior effects achieved in the present invention have not been described in the literature so far and are exemplified by the following examples. Example 1 50 wt. glycoluril (90 min dried at 80-85 ° C) was added to 500 parts by volume of nitric acid (99.15%) with stirring for 4-5 minutes. The temperature of the reaction mixture was maintained at room temperature for 24 hours by adding glycoluril. Deň: 27 ° C. This is followed by an increase in the temperature of the reaction mixture by external heating over 6 to 7 minutes to 50 to 53 ° C and is maintained for 45 minutes in this temperature range. After this time, the nitration is carefully passed into a 1000 vol. The resulting suspension is refluxed for 10 minutes and after cooling to 15-20 ° C, the product is isolated by filtration, washed with water on the filter until neutral reaction of the outgoing filtrate, and then dried in a thin layer at 80-85 ° C for 4 hours.

This basic procedure has been repeatedly reproduced, with certain amounts of urea dissolved in the present nitric acid prior to the introduction of glycoluril. The results are presented in the following table:

The amount of urea in the 1,4-dinitro-glycoluril nitric acid extract. dlely hmot. % to weight gain. % vs. glycoluril 0.0 0.0 67.0 82.04 0.2 0.4 68.7 84.12 0.7 1.4 69.2 84.73 1.4 2.8 68.7 84.12 3.5 7.0 68.1 83.38 5.5 11.0 67.5 82.65

Claims (1)

Example 2 Nitration of glycoluril is performed as in Example 1, except that the glycoluril used in an amount of 50 wt. of the parts is mixed with 1 wt. of urea of the same quality as in Example 1. 67.9 wt. dielovdinitroglycoluril, which represents 83.14% over theory. SUBJECT A process for preparing 1,4-dinitro-tetrahydroimidazo [4,5-d] imidazole-2,5 (1H, 3H) -dione by nitration tetrahydroimidazo [4,5-d] imidazole-2,5- ( Characterized in that the nitration process is carried out in a urea medium added to the nitration system at one time or at a rate of 0.05 to 15.0% by weight, preferably at a concentration of 0.05 to 15.0% by weight. 0.4 to 11.0% by weight, based on the weight of the branethotetrahydroimidazo [4,5-d] imidazol-2,5 [1H, 3H] -dione reaction. I V