SU435235A1 - METHOD OF PREPARING DIPIPERIDINDINITROXYL ALUMINUM SERIES - Google Patents

Description

one

The invention relates to a process for the preparation of new compounds which can find wide application in the chemical industry.

Provided based on the known method of producing radicals by oxidation process for producing alkane dipiperidindinitroksilov -p yes zaklyuchayuschys that triacetonamine subjected to condensation with acetylene, the resulting piperidine was subjected etinilkarbinol dimerization followed by hydrogenation, dehydration, catalytic hydrogenation and re-oxidation of the glycol or its dipiperidilbutana and the selection of the target product in a known manner.

Example 1. Synthesis of 1,4-bis (2,2,6,6-tetramethyl-1-oxyl-4-hydroxy-4-pi1-peridyl) butane.

In a three-neck flask with a capacity of 0.5 l, equipped with a stirrer and a calcium chloride tube, 80 g of finely divided caustic potash and 300 ml of dry dimethylformamide are charged, then the suspension is cooled to 0 ° C and acetylene is passed through it for 1 hour, after which 70 g dry triacetonamine in small portions with continuous passage of acetylene for 4 hours. Next, the reaction mixture is poured into a glass with ice (200 g of ice). The precipitate is filtered off.

washed with water and dried in a vacuum desiccator. Obtain 80 g (yield quantitative 4etinyl-2, 2,6,6-tetramethyl - 4-piperidol, T. pl. 213 ° C (after sublimation in a vacuum sublimator). Found,%: 73.05; H 10, 51; N 7.76. Calculated: C 72.98; H 10.50; N 7.73. 80 g of the obtained compound, 180 g of ammonium chloride, 112 g of copper chloride, 90 ml 6N hydrochloric acid and 800 ml of water. Then a concentrated solution of ammonia is added to -pH 5.5 and then oxygen is bubbled through the suspension for 8 hours with vigorous stirring.

Next, the reaction mass of the bed is washed with ammonia solution, the precipitate is filtered off, washed with ammonia solution and water and dried in a vacuum desiccator. Obtain 76 g (92%) of 1,4-bis (2,2,6,6-tetramethyl 4-hydroxy-4-piperidyl) -butadiene - a white substance, so pl. 248 ° C. For analysis, it is purified by sublimation in vacuum (0.1 mmHg). Found,%: C 73.18; H 9.98; N 7.89.

С22НзбН2О2.

Calculated,%: C 73.29; H 10.07; N 7.77.

The product obtained above is loaded into

steel rotating autoclave tank

2 L, 1 L of methanol and 15 g are added to it.

Rene nickel, then hydrated at 70 ° C

and a hydrogen pressure of 200 atm for 6 hours. The solution is then filtered off from the catalyst and the solvent is evaporated in vacuo. 72 g (90%) of 1,4-bis (2,2,6,6-tetramethyl 4-hydroxy-4-pi. Peridyl) butane are obtained - a colorless substance, which crystallizes from hexane as colorless needles, m.p. 124 ° C. Found,%: C 71.44; H 11.92; N 7.73.

C22H44N202.

Calculated,%: C 71.68; H 12.03; N 7.60.

20 g of 1,4-bis (2,2,6,6-tetramethyl-4-hydroxy-4-pigleridyl) butane is dissolved in 300 ml of methanol and 2 tons of sodium tungstate, 0.5 g of trilon B and 20 ml of 30% hydrogen peroxide. The reaction mixture is kept for 15 days at room temperature, then the catalyst is filtered off and the solvent is evaporated in vacuo. The oxidation product is chromatographed on a column filled with alumina (eluent chloroform). Next, the first colored fraction with Rf 0.7 is collected, chloroform is evaporated in vacuo, and the red solid residue is recrystallized from hexane. Get 16 g (75%) 1,4-bis (2,2,6,6-tetramethyl-1-oxyl-4 - hydroxy - 4piperidyl) butane in the form of orange needles, so pl. 220 ° C.

Found,%: C 66.04; H 10.59; N 7.18.

C22H42N2O4.

Calculated,%: C, 66.37; H 10.52; N 7.04.

The EPR spectrum of the compound obtained in a solution of hexane is quintipleten.

Example 2. Synthesis of 1,4-bis (2,2,6,6-tetramethyl-1-oxyl-4-piperidyl) butane.

Dehydration 1,4-bis (2,2,6,6 - tetramethyl-4oxy-4-piperidyl) 1 butane.

In a 0.5 L round bottom flask equipped with a reflux condenser, 20 g of 1,4-bis (2,2,6,6-tetramethyl-4-hydroxy-4-piperidyl) butane (see Example 1) are added, 100 ml of water and 100 ml of concentrated sulfuric acid. The reaction mixture is heated on a boiling water bath for 8 hours, then cooled with ice, the contents of the flask are neutralized with alkali and extracted with ether. The ethereal extract is kept by lottery and distilled off. Receive 20 g (quantitative yield) of the dehydration product, so pl. 5 ° C. Rf 0.75 (pa alumina; eluent-mixture acetone-methanol, 3: 2).

Found,%: C 79.65; H 12.21; N 8.47.

C22H4oN2.

Calculated,%: C 79.51; H 12.05; N 8.44.

In a steel rotating autoclave with a capacity of 0.5 liters, 20 g of the substance obtained above, 100 ml of methanol, 5 g of Rene nickel are entrapped and hydrogenated at a hydrogen pressure of 200 atm and 5 at 70 ° C for 8 hours. The catalyst is then filtered off and the methanol is evaporated under vacuum. 15.5 g (75%) of 1,4-bis (2,2,6,6-tetramethyl-4-pi: peridyl) butane are obtained - a colorless crystalline substance, so pl. 90 ° C (from hexane). Rt 0.34 (on alumina; eluent is a mixture of acetone-methanol, 6: 1).

Found,%: C 78.81; H 13.18; N 8.21.

C22H44N2.

Calculated,%: C 78.73; H 13.09; N 8.34.

To a solution of 10 g of the obtained compound in 100 ml of methanol was added 1 l of sodium tungstate, 0.2 g of trilon and 10 ml of 30% hydrogen peroxide. The reaction mixture was incubated for 8 days at room temperature. The precipitated orange crystals (3 g) are filtered off with suction and washed with water, the methanol solution of the biradical is evaporated under vacuum, and an additional 6 g of oxidation product is recovered. The resulting biradical is further purified by chromatography on an alumina column (eluent is chloroform). Then the first orange fraction is taken with a Rr of 0.8. After evaporation of the chloroform, the

chromatographically pure 1,4-bis-2,2,6,6-tetramethyl-1-oxyl-4-piperidyl) butane in the form of orange crystals, so pl. 104 ° C. Yield 6.5 g (62%). Found,%: C 72.24; H 11.52; N 7.37.

cC22H42N2O2.

Calculated,%: C 72.18; H 11.48; N 7.15.

The EPR spectra of the obtained compound in solutions of hexane, benzene, chloroform, and quintipleten alcohol.

Subject invention

The method of producing diperidinidine nitroxides of the alkane series, characterized in that triacetonamine is subjected to condensation with acetylene, the resulting ethynylcarbinol piperidine is subjected to dimerization followed by hydrogenation, dehydration, re-hydrogenation and catalytic oxidation of the obtained dipiperidine by an outline.