SU578885A3 - Method of preparing 2,5,8,-tris-(o-or p-nitrophenyl-tris-triazolebenzol) - Google Patents

Description

(54) METHOD OF OBTAINING 2, 5, 8-TRIS - (O- OR L - NITROPHENYL) - TRIS-TRIAZOLOBENZENE

dimethylformalt, dimethylacetamide, pyridine, water, or mixtures thereof. It is preferable to use a mixture of dimethylformamide with pyridine in a ratio of 2: 1-1: 2.

The oxidation process is carried out with heating, preferably at 50-100 ° C or the boiling point of the solvent.

Target contacts are crystallized by known methods from a suitable solvent, preferably nitromethane.

During the oxidation process, water is added to the reaction mixture, the temperature is raised to the boiling point and the mixture is heated under reflux until the solution turns yellowish-brown. Thereafter, the reaction mixture is cooled, the separated product is filtered off, washed with water, then with a dilute solution of ammonium hydroxide, dried, and, if desired, purified by recrystallization. The compounds are recrystallized, preferably from N-methylpyrrolidine. In this reaction, 2,5,8 - tris - (o - or p-nitrophenyl) - tris - triazobenzene is formed.

In the event that it is desired to obtain compounds containing a larger number of nitro groups, the 2,5,8-tris - (o - or p-nitrophenyl) -tris - triazolobenzene obtained before this is reacted with a nitration agent, such as a nitrous mixture, prepared from nitric acid (sp. weight 1.50) and concentrated sulfuric acid.

Examples illustrating the invention do not limit its scope.

The percentages given in the examples are by weight.

Example 1. 2,5,8-tris- (o-nitrophenyl) -tris-triazolbenzene, 41.4 g, (0.3 mol), o-nitroanine, and 700 ml of dimethylformamide are introduced into a 1.5-liter flask equipped with a stirrer, thermometer and addition funnel, and 100 ml of concentrated hydrochloric acid is added to the solution with stirring. The mixture is cooled in an ice bath to a temperature from 0 to 5 ° C (in a flask) after which 21 g (0.305 mol) of sodium nitrite dissolved in 60-70 ml of water is added, and precautions are taken so that the temperature of the mixture does not exceed 5 ° WITH.

After adding the entire volume of the sodium nitrite solution, the mixture is stirred at 0-5 ° C for the next 30 minutes and then a solution of 23 g (0.09 mol) of 1,3,5-triaminobenzene hydrochloride in 20 ml of pyridine and 50 ml of water is added. Put into the flask with the observance of precautions so that the temperature of the mixture does not exceed 5 ° С. The reaction mixture is stirred for an additional 30 minutes, after which the dark purple color azo compound is filtered, washed with hot water and ethanol, and dried.

At the same time I get 48.2 g (84.4%) of raw 13.5 to amino-2,4,6 - (about nitrophenylazo) -benzene;

m.p. 341-342 C (after recrystallization from N megilpyrrolidone).

C24H, 8N2i06

Calculated,%: C, 50.70; IZ, 18; N 29.46. Paydeno,%: C 50.31; H 3.30; N 29.10.

Characteristic absorption bands in the infrared, 3050 (weak), 1594 (very strong), 1518 (very strong), 1461 (weak), 1448 (average), 1375 (very strong), 1305 (strong), 1274 (average), 1241 (average), 1211 (average), 1145 (average), 1120 (strong), 1082 (weak), 1041 (weak), 990 (very weak), 957 (strong), 869 (average), 855 (very weak ), 845 (average), 779 (average), 742 (strong), 690 (average), 577 (average), 540 (weak) and 510 (strong).

.5 / g crude 1,3,5 - triamio - 2,4,6 - tris - (o nitrophenylazo) - benzene is introduced into a 1.5 l flask equipped with a stirrer, a thermometer and an inlet. 400 ml of dimethylformamide and 400 ml of pyridine were added to the solid and the mixture was heated to a temperature of 60-90 ° C with stirring, and then 60 g of anhydrous copper sulfate was introduced into the flask. After that, a reflux condenser is placed in the inlet and the mixture is heated at a temperature of 100 ° C. 80 ml of water is added to the system and the solution is boiled until its color turns into the same toaaTO-brown (30 min). The reaction mixture is cooled, the separated product is filtered off, washed first with water and then with a 5% solution of (aqueous) hydroxide to obtain colorless wash water. The wet product is dried to obtain 20 g of a yellowish white 2,5,8 - tris - (o - nitrophenyl) -tris-triazolobenzene; m.p. 324-327 ° C.

After recrystallization from dimethylformamide, 16 g of a purified product are obtained with a mp. 327-328 ° C.

C34Hi2N, 506

Calculated,%; C, 51.25; H2.14; N 29.78.

Found,%: C 51.43; H 2.34; N 29.61. Below are the characteristic absorption bands in the infrared spectrum, 3090 (weak), 1620 (weak), 1606 (average), 1538 (very

.Strong), 1496 (forces; a), 1455 (average), 1369 (very strong), 1322 (weak), 1308 (average), 1203 (weak), 1164 (average), 1114 (average), 1057 (weak ), 959 (strong), 870 (weak), 854 (strong), 775 (strong), 752 (weak), 741 (very

is strong), 726 (average), 709 (strong), 667 (average), 699 (average), 583 (weak), 568 (weak), 511 (weak), 480 (weak).

 and measure 2. 2,5,8 - gris - (and - nitrophenyl) - tri-triazolobenzene.

150 ml dimethylacetamide is introduced into the flask

volume of 500 ml, equipped with a stirrer, thermometer and addition funnel, and in which 8.25 g (0.06 mol) of p-nitroaniline is dissolved.

20 ml of concentrated hydrochloric acid is added to the solution and the mixture is cooled to 5 ° C.