SU199901A1 - METHOD FOR OBTAINING POLYFLUORINATED COMPOUNDS CONTAINING NFa-rPynObl - Google Patents

Description

A method is known for producing compounds containing Lp2-groups, by fluorinating compounds with NH and HH2 groups with elemental fluorine during cooling. However, in this case, only amino groups are fluorinated.

In order to obtain polyfluorinated compounds containing NFs-rpynny, it has been proposed to fluorinate partially fluorinated imino-amines or keto-amines in hydrogen fluoride solution with hydrogen fluoride at minus 10 to plus 10 ° C with elementary fluorine. Under these conditions (solution in HF, 0 °), hydrocarbon amines and the reaction is characteristic only for fluorinated amines.

The starting iminoamines and ketoenamyls are derived from polyfluorinated cycloalkenes. Thus, by the action of ammonia on 1,2-dichlorooctafluorocyclohexene in a pyridine solution, 1 - amine - 3-imin-2-chlorohexafluoro-1-cyclohexene is isolated in a quantitative yield.

Fluorination is carried out in a 350 ml metal reactor with a propeller stirrer. The reactor is equipped with a lid on the flange in which the reflux condenser, thermocouple sleeve and bubbler for feeding fluorine are fixed. The reactor is cooled in an ice bath. Fluoridation is carried out with undiluted fluorine fed from the electrolytic bath without prior purification. The need to dilute fluorine with nitrogen, which was previously used in known processes, but the proposed method is no longer necessary, since hydrogen fluoride (low-boiling and fluorine-resistant) dilutes the substance in solution. The exceptional softness of the process (low temperature, good mixing and adjustable amount of fluorine), as well as the specificity of the starting material (ammonium form in HF solution, the absence of hydrogen atoms and double bonds in the final product and its insolubility in HE) provide a high yield of the target product. Successful fluorination of iminoenamine and ketoenamine suggested that amidines and amides of f-acids having the system of St IIII

Zei NH.-C-C-C NH or NHa-C-NH will be fluorinated in the same way, giving

MPA compounds.

The starting amidines of f-carboxylic acids are isolated by methods described in the literature. Amidines of fluorocarboxylic acids dissolve well in HF, but, apparently,

they are converted to iminofluorides, which are also subjected to fluorination. Therefore, as a result of the fluorination of amidine in a solution of IE, a mixture of products containing one and two LiPa groups creeps. Thus, fluoro1,6,6-tetra- (difluoroamine) decafluorohexane and 1,6-di- (difluramine) dodecafluorohexane.

Nitriles are also well soluble in anhydrous HF, but apparently they do not form imidhalides as a result of the addition of HF in the -CHss N bond, and the interaction is limited to the formation of the complex. Therefore, the nitriles of the f-acids under these conditions are not subjected to fluoridation and are returned unchanged upon dilution of the reaction mixture with water.

The amides of the f-acids under the action of anhydrous oxide immediately transfer to the fluorine anhydrides of the f-acids, therefore, it is not possible to obtain MP2-containing compounds.

Example 1. Preparation of 1,3- (difluoroamine) -2-chlorooctafluorocyclohexane.

A solution of 45 g of dichlorooctafluorocyclohexane in 120 ml of dry pyridine is made with ammonia. The temperature of the reaction mass rises to 50 ° C and gradually drops to room temperature, which characterizes the end of the reaction (-5 hour). The reaction mass, which is a thick reddish suspension, can be treated in the following two ways:

a) The reaction mass is poured into 0.5 l of water, extracted with 0.3 l of ether, the extract is washed four times with 0.5 l of water, dried with NaaCOs and the ether is distilled off, the solvent is distilled off in vacuum. 200 ml of CCS are added to the obtained product, boiled for 5 minutes, filtered. The crystals precipitated upon cooling are filtered off. Weight 34 g (92%).

b) Pyridine is completely distilled off from the reaction mass in a water jet pump vacuum in a boiling water bath. Heated SCC (150 ml) is added to the residue, filtered, the precipitate is washed with hot CCl, j (150 ml). Carbon tetrachloride is distilled off from the extract, the residue is distilled in vacuum, collecting a fraction 103-108 ° C (4 mm Hg). A colorless crystalline mass is obtained. Weight 30 g (80%).

1 - amine-3-imin-2-chlorohexafluoro-1-cyclohexane (I) has m.p. 105 ° С (4 mm of mercury), t. Pl. 99-99.5 ° C.

Found,%: C 28.40; H 1.03; C1 14.10; F 45.11; N 11.37.

CeHgClFeNs.

Calculated,%: C 28.52; H 1.19; C1 14.05; F 45.15; N 11.09.

Into a solution of 35 g of substance I in 80 ml of anh. HP fluorine obtained in an electrolytic bath at a current of 80 a, is bubbled for 1 hour with vigorous stirring at a temperature of 0-10 ° C, which is achieved by cooling the reactor in an ice bath. At the end of the exposure, a strong fluorine breakthrough and the absence of heating are observed, which characterizes the end of the reaction. The product (bottom layer) is distilled off from hydrogen fluoride, washed with 5% NaOH solution, dried with AlgSO4 and distilled with a column, collecting a fraction of 128-133 ° C. Weight 45 g (85%). Distill again. 1,3-di (difluoroamine) -2 - chlorononafluorocyclohexane (I) has m.p. 130-131 ° С (745 mm of mercury); 1.8640; p2o 1.3470.

Found,%: C1 9.02; F 64.45; N 7.11.

CsClFigN ,.

Calculated,%: C1 9.28; F 64.58; N 7.32.

Hydrogen fluoride, separated from the reaction product, is evaporated, the residue is dissolved in

10 ml of water and iodine with concentrated H9SO4, 5 g (10%) of 3-difluoroamine-2-chlorooctafluorocyclohexanone hydrate are separated.

P1K - spectrum: there is no sweep in the region of 1400-3500 CM-i. Band 831 is characteristic of NFo-rpynn. The NMR spectrum of the resulting compound is very complicated due to the fact that some axial and equatorial fluorine atoms give separate signals. Peaks with chemical shifts -27.6 and - | -156.5 ppm

relative to the internal standard CClgF correspond to fluorine atoms in the -NF2 groups and tertiary fluorine atoms.

The intensity ratio 2: 1 corresponds to the number of fluorine atoms in the molecule.

Substance II is a colorless liquid, gives a positive reaction with an acetone KU solution, it has a characteristic, nauseous smell. Example 2. Preparation of 3-difluoroamine-2-chloro-octafluorocyclohexanone.

A solution of 25 g of substance I in 800 ml 2 n. HC1 is maintained at a temperature of 15 ° C for 2 hours. The crystalline precipitate is filtered off, the filtrate is extracted with ether,

the ether is distilled off. Get 22 g (88%) of 1-amin3-keto-2-chlorohexafluoro-1-cyclohexane (111) with T. pl. 81-82,5 ° С (from SCC) - needles are colorless.

Found,%: CI 13.92; F 44.81; N 5.61.

CJisCIFeKO.

Calculated,%: C1 14.06; F 44.97; N 5.53. Fluorine (current 70 a) is bubbled into a solution of 20 g of substance III in 100 ml of anh. at a temperature of 3-10 ° C. In the end

Exposure observed strong fluoride breakthrough. Hydrogen fluoride is evaporated from the reaction mixture in a water bath, the residue is diluted with 50 g of ice and 30 ml of horses ,. H2S04 and extracted with ether. The ether is distilled, residues

the ether is stripped off in vacuo. 30 g of PgOs are added to the resulting mass while cooling and the product is distilled off; 14 g (54%) of distillate boiling in the range of 100-115 ° C are obtained. Re-distillation gives 3-difluoroamine-2-chlorooctafluorocyclohexanose: colorless, fuming on the air, a liquid with a strong odor (vanilla smell in a diluted state), t. bale. PO-111 ° C (752 mm Hg. Art.);

Wed 1J720; 1.3545.

Found,%: C1 9.89; F 54.95; N 4.32 (due to the strong hydroscopicity, it is necessary to count on the monohydrate obtained in the process of taking a sample of the substance in the analysis). CoClFioNO NgO.

Calculated,%: Cl 10.28; F 54.99; N 4.05.

IR spectrum 832 and 1796. In the NMR spectrum of this compound, the peaks with a chemical shift relative to the internal standard CClgF -27.5 and - (- 165 ppm belong to the fluorine atoms in NFo-rpynne and the tertiary fluorine atom, the ratio of signal intensities is 2: 1, which corresponds to the amount of fluorine atoms in the compound.

Example 3. Fluoridation of perfluoroadipoamidine.

In a solution of 29 g of amidine f-adipic acid, 45 M.L, anh. HF was bubbled in fluorine (current 70a) for 1 hour at a temperature of 3--10 ° C. Hydrogen fluoride was drained from the liquid product, which was dried with KF, filtered, and distilled under vacuum. Weight 23 g (50%). The product has t. Kip. 75-76 ° C (170 lag Hg. Art.), 1,760; Pts 1,299 - colorless liquid with a strong odor.

Found,%: F 72.97; N 9.35.

IR spectrum: no absorption in the double bond region, the NMR spectrum consists of six peaks with a chemical shift of -24.3; -17.0;

+ 110.0; + I6,6; 120.8 and 123.7 ppm. When comparing with the NMR spectrum of perfluoro-1,5-azapentane (-17; +116 and +123 ppm), it can be seen that the product contains 60-70% 1.6 - di (diftoramin) dodecafluorohexane.

Calculated,%: F 75.24; N 6.93.

A peak with a chemical shift of -24.3 ppm is related to NFo-rpynnaM bound to a tertiary carbon atom, therefore the remaining 30-40% is 1,1,6,6-tetra- (difluoroamine) perfluorohexane.

Calculated,%: F 72.76; N 11.91. Elementary analysis and data from a gas-liquid chromatograph {i.

Subject invention

A method of producing polyfluoride compounds containing NFg-rpynnbi by fluorination with elemental fluorine at a low temperature, characterized in that the partially fluorinated ketoenamines or iminoenamines are fluorinated in a solution of hydrogen fluoride at a temperature of minus 10 to plus 10 ° C.