DE1170959B - Process for the preparation of the chlorocyan tetramer - Google Patents

Description

Process for the preparation of the cyanogen chloride tetramer The invention relates to a process for the preparation of the chlorocyan tetramer (CICN) 4.

According to the invention, chlorine and hydrocyanic acid in tetrachloroethane are used as Solvents reacted with one another in a molar ratio of about 1.2: 1, whereby the hydrocyanic acid in a small amount tetrachloroethane, the chlorine in one about six times the amount of solvent required to dissolve the hydrocyanic acid Amount of tetrachloroethane is dissolved. These solutions are separated from each other in a sealable reaction vessel introduced, after sealing the same for Exposure to one another and then to a temperature of 60 ° C for 4 hours heated. After cooling and opening the reaction vessel and blowing off the resulting Hydrogen chloride, the resulting reaction liquid is divided into two parts and reload with hydrocyanic acid or chlorine. The course of the reaction is in the above repeatedly repeated, starting with the third repetition cyanuric chloride separating out in large quantities on cooling the fully reacted solution before the renewed chlorine or. Hydrocyanic acid addition is filtered off. The filtrate becomes the Chlorcyantetramer obtained by fractional distillation.

This compound has a bp.9 = 85 ° C, a refractive index n- = 1.570 and a density of 1.67 at a temperature of 21.5 ° C, based on Water of the same temperature. This compound does not crystallize on cooling, it only thickens at temperatures around -70 ° C. Your smell is similar that of cyanuric chloride.

In the following the preparation of the chlorocyan tetramer is exemplified described. Example 145 cm3 of tetrachloroethane are poured into a large or thick one Glass tube, cools to about -30 ° C and dissolves 0.32 mol of chlorine in it, the reaction mixture is protected as well as possible against humidity.

In a second, smaller glass tube than the first, 25 cm3 of tetrachloroethane and dissolved in this 0.258 mol of hydrocyanic acid.

Then the small tube is inserted into the large one so that it rests on the The surface of the chlorine solution floats. The thick tube is sealed tightly by melting and inserted into a protective metal tube. By reversing and moving the pipe the chlorine solution and the solution of hydrocyanic acid are mixed together. The tube is placed in an oil bath at a temperature of 60 ° C. for 4 hours used to accelerate the polymerization of cyanogen chloride. The tightly closed The tube is then taken out of the protective sleeve and opened after cooling to -75 ° C. The hydrochloric acid formed during the reaction is removed by degassing.

The reaction liquid is divided into two parts, namely into a portion of 145 cm "and one of 25 cm3. Each portion is repeated in such a way Chlorine or hydrocyanic acid loaded that the starting reaction solutions are restored will.

The two solutions are then made in the same way as above described, in a tightly sealed tube, which was opened again for 4 hours 60 ° C is heated, mixed.

The liquid reaction mixture of the second step is on the same Way, as previously described, fed to a third operation.

From the third step on, the reaction liquid separates When cooling down, cyanuric chloride crystals fall off, which each time before the new operation be filtered off. Enrichment of the solvent with cyanogen chloride tetramers is continued by doing this in the same way in a further nine consecutive Operations is treated. That after the twelfth step resulting liquid reaction mixture is fractionated after filtration Subjected to distillation under a water jet vacuum. A Vigreux column is used for this with a head used for total reflux and partial withdrawal. To this Most of the tetrachloroethane is recovered.

The residue remaining after cooling is partly liquid and partly crystallized. It is filtered, resulting in 63 g of a yellow liquid (n1- ' = 1.5435; d1; 15 = 1.65) which is less mobile than tetrachloroethane. This liquid is subjected to another distillation under increased vacuum using a small fractionating column without reflux.

This gives a) essentially pure tetrachloroethane in the trap located between the pump and the distillation apparatus and cooled with liquid nitrogen; b) a main fraction of 12 g of a colorless liquid (n21.9 = 1.570) in the collecting vessel; c) a few drops of distillation residue; d) some crystals of cyanuric chloride in the column and the condenser.

The main fraction mentioned results after further rectification a fraction of 6 g which passes over at 85 ° C / 0.9 mm Hg (d1 ',; 1 = 1.67; no = 1.570). The first fraction has a refractive index of no = 1.561, the residue of nD = 1.570. The percentage composition of the last main fraction is the same like that of cyanogen chloride. The molecular weight determined by cryometry in benzene is 240, which is approximately the theoretical molecular weight of the cyanogen chloride tetramer corresponds to, namely 246.

This tetramer can form with a yield of 80% of theory, based on the hydrocyanic acid used. Like cyanuric chloride, the cyanogen chloride tetramer enables the production of a large number of new compounds through various substitutions, which. Intermediate substances in the manufacture of valuable products that are used in particular in the plastics industry.

Claims (1)

Claim: Process for the production of the cyanogen chloride tetramer. characterized in that chlorine and hydrocyanic acid in tetrachloroethane as solvents in a molar ratio of about 1.2: 1 are reacted with each other by the hydrocyanic acid in a small amount of tetrachloroethane, the chlorine in a compared to the amount of solvent required to dissolve the hydrocyanic acid about six times Amount of tetrachloroethane is dissolved, the solutions are introduced separately from one another into a sealable reaction vessel and, after closing the same, are brought to act on each other, then heated to a temperature of 60 ° C for 4 hours, after cooling and opening the reaction vessel, the hydrogen chloride formed is blown off The resulting reaction liquid is divided into two parts and one part is again loaded with hydrocyanic acid and the other part is loaded with chlorine and the course of the reaction is repeated several times in the above-mentioned manner, with the third repetition increasing as the reacted solution cools down A larger amount of cyanuric chloride separating out is separated off by filtration before the renewed addition of chlorine or hydrocyanic acid, whereupon the cyanogen chloride tetramer is finally obtained from the filtrate by fractional distillation. Considered publications German Auslegeschrift No. 1098 518.