RU2598434C2 - Method of decontaminating liquid wastes of process of producing organic azides containing azides of alkali metals - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry and can be used in production of organic azides. Proposed method of decontaminating azide ions in a liquid wastes of process of producing organic azides by switching to ammonium four-substituted azide and subsequent removal from reaction mass. For this purpose shortly before completion of four-substituted chloride azidation process is added to the reaction mass of ammonia. Obtained four-substituted ammonium azide further can be effectively used to produce organic azides.

EFFECT: technical result is increased safety of process of decontaminating and recycling azide ions in waste production of organic azides with simultaneous increase of efficiency of their production.

1 cl, 4 ex

Description

The present invention relates to the field of chemistry and may find application in the production of organic azides.

Organic azides are obtained by the action of sodium azide on aliphatic and aromatic halogen-containing compounds (Organic azides. Chemical encyclopedia. T.1. M: Publishing house "Soviet Encyclopedia", 1998. - P.74):

RHal + NaN ₃ → RN ₃ + NaHal

In this regard, organic azides can be obtained, for example, by reacting organochlorine compounds with sodium azide in an organic solvent by reaction

RCl + NaN ₃ → RN ₃ + NaCl

During the process, in order to increase its efficiency, sodium azide is taken with a certain excess (10 ... 100% of theoretically necessary). At the end of the reaction, a mixture of salts is formed in the precipitate, consisting of crystalline sodium chloride and a solution of excess sodium azide, which cannot be discharged into the sewer as a part of wastewater without preliminary decomposition of sodium azide due to its high toxicity.

There are various methods for neutralizing the azide ion. As a rule, all methods are based on the decomposition of the azide ion. So, for example, in the RF patent №2123211 of 12/20/1996, the destruction of the azide ion is carried out using the electrochemical treatment of liquid waste, and in the RF patent No. 2194320 of 11/28/2000, the azide ion is destroyed using permanganates, and / or dichromates and / or alkali metal ferrates in an acidic environment. The disadvantages of these methods include the toxicity of the reagents used and the loss of the azide ion during its destruction.

The closest method of neutralizing azide ions in solutions, in its simplicity and reliability, is a method based on the treatment of liquid waste with a solution of nitric or sulfuric acid in the presence of sodium nitrite (Chemistry and technology of initiating explosives. Bagal LI - M.: Engineering, 1975. S. 224-225). However, this method of neutralization, like others, is based on the destruction of the azide ion, i.e. its irretrievable loss, which is economically unprofitable due to the high cost of alkali metal azides. To destroy the azide ion in this method, fairly toxic and harmful reagents are used - nitric acid and sodium nitrite. In addition, during the destruction of the azide ion, there is a danger of the release of extremely explosive and toxic nitric acid, which increases the risk of the process of neutralizing liquid waste.

The technical result, the solution of which the invention is directed, is to increase the safety of the process of neutralization and utilization of azide ions in organic azide production wastes while increasing the economic efficiency of their production.

The technical result is achieved by the fact that in the method of neutralizing liquid waste from the process of producing organic azides containing alkali metal azides by removing azide ions before the end of the process of azidation of the organic chloride with alkali metal azide in an organic solvent, tetra-substituted ammonium chloride is introduced into the reaction mass, after which the reaction mass incubated at a temperature of 95 ... 99 ° C for 2.5 ... 3.5 hours, and then cooled to 25 ... 30 ° C and the precipitate of alkaline chloride formed is filtered off talla, and 2/3 ... 3/4 of the organic solvent is distilled off from the filtrate and toluene or benzene is added in proportion to the remaining organic solvent 3: 5 ... 5: 1, and a tetra-substituted ammonium azide precipitate from the solution, which is filtered off and used in the process azidation, and a solution of organic azide is directed to the selection of the target product.

As an example, the method of neutralizing the azide ion in the process of azidation of various aliphatic and aromatic halogen-containing compounds with sodium and potassium azides is given.

Example 1

In a solution of 0.1 mol (27 g) of formaldehyde dichlorohydrin glycerol in 108 ml of dimethylformamide, 0.44 mol (28.6 g) of sodium azide (excess sodium azide 10%) is charged. Then, 0.04 mol (6.06 g) of methyltriethylammonium chloride is added, after which the reaction mass is maintained at a temperature of 97 ... 99 ° С for three hours, cooled to 25 ... 30 ° С, the precipitate of sodium chloride is filtered off from the filtrate 81 ml of dimethylformamide are distilled off under vacuum, 108 ml of toluene are added and the precipitated precipitate of methyltriethylammonium azide is filtered off. The yield of methyltriethylammonium azide is 5.688 g (0.036 mol), and the content of the main substance in it is 97 ... 99%. The isolated methyltriethylammonium azide is used in the next step to obtain organic azides.

Example 2

0.48 mol (38.9 g) of potassium azide (excess potassium azide 20%) is charged into a solution of 0.1 mol (27 g) of formaldehyde of glycerol dichlorohydrin in 118 ml of dimethylformamide. Then, 0.08 mol (12.12 g) of methyltriethylammonium chloride is added, after which, to complete the process, the reaction mass is kept at a temperature of 95 ... 98 ° С for three hours, cooled to 25 ... 30 ° С, the precipitate of potassium chloride is filtered off from the filtrate 90 ml of dimethylformamide are distilled off under vacuum, 108 ml of benzene are added and the precipitated precipitate of methyltriethylammonium azide is filtered off. The yield of methyltriethylammonium azide is 5.688 g (0.036 mol), and the content of the main substance in it is 98 ... 99%. The isolated methyltriethylammonium azide is used in the next step to obtain organic azides.

Example 3

0.0594 mol (3.86 g) of sodium azide (excess of sodium azide 10%) is charged into a solution of 0.027 mol (5 g) of bis- (β-chloroethyl) nitramine in 25 ml of dimethyl sulfoxide. Then, 0.0054 mol (0.813 g) of methyltriethylammonium chloride is added, after which the reaction mixture is kept at a temperature of 97 ... 99 ° С for 2.5 hours, cooled to 25 ... 30 ° С, the precipitate of sodium chloride is filtered off from the filtrate 16 ml of dimethyl sulfoxide are distilled off under vacuum, 36 ml of toluene are added and the precipitated precipitate of methyltriethylammonium azide is filtered off. The yield of methyltriethylammonium azide is 0.851 g (0.0054 mol), and the content of the main substance in it is 97 ... 98%. The isolated methyltriethylammonium azide is used in the next step to obtain organic azides.

Example 4

In a solution of 0.1 mol (17.66 g) of benzenesulfonyl chloride in 75 ml of acetonitrile, 0.11 mol (7.128 g) of sodium azide (10% excess sodium azide) was charged. Then, 0.0099 mol (1.505 g) of methyltriethylammonium chloride is added, after which the reaction mass is maintained at a temperature of 96 ... 99 ° С for three hours, cooled to 25 ... 30 ° С, the precipitate of sodium chloride is filtered off from the filtrate under vacuum 56 ml of acetonitrile are distilled off, 76 ml of benzene is added and the precipitated precipitate of methyltriethylammonium azide is filtered off. The yield of methyltriethylammonium azide is 1.575 g (0.01 mol), and the content of the main substance in it is 98 ... 99%. The isolated methyltriethylammonium azide is used in the next step to obtain organic azides.

It is important to note that the azide ion removed from the waste in the form of tetra-substituted ammonium azide accelerates the azidation process in the production of organic azides, since tetra-substituted ammonium azides are more reactive than, for example, sodium or potassium azides (The effect of the cation of the nitric acid salt and the type of solvent on the rate of the azidation reaction / I.K. Kukushkin, V.T. Kosolapov, V.A. Zlobin // University proceedings: Chemistry and chemical technology - T. XVIII. - 1975. - Issue 7.- S. 1043-1047) .

Claims (1)

The method of neutralizing liquid waste from the process of producing organic azides containing alkali metal azides by removing azide ions, characterized in that before the end of the process of azidation of the organic chloride with alkali metal azide in an organic solvent, tetra-substituted ammonium chloride is introduced into the reaction mass, after which the reaction mass is maintained at at a temperature of 95-99 ° C for 2.5-3.5 hours, and then cooled to 25-30 ° C and the precipitate of alkali metal chloride formed is filtered off and distilled off from the filtrate t of 2 / 3-3 / 4 organic solvent and toluene or benzene is added in the ratio of the remaining organic solvent 3: 5-5: 1, while a precipitate of tetra-substituted ammonium azide precipitates, which is filtered and used in the process of azidation, and the organic solution azide is directed to the selection of the target product.