DE933482C - Process for the preparation of polymers from N-carbonic anhydrides of alicyclic ª ‡ -aminocarboxylic acids - Google Patents

Description

Process for the preparation of polymers from N-carbonic anhydrides of alicyclic α-Aminocarboxylic Acids The invention relates to the preparation of polymers from N-carbonic anhydrides of alicyclic a-aminocarboxylic acids with an unusual ring structure.

In these N-carbon anhydrides to be polymerized according to the invention of α-aminocarboxylic acids is the carbon between the amino nitrogen atom and the acyl carbon atom is a spiro carbon atom, d. H. which forms carbon the one common link of two rings, one of which is the N-carbonic anhydride ring is. The condensation of these low-carbon anhydrides, with evolution of carbon dioxide then leads to linear polymers and possibly mixed polymers.

The N-carbonic anhydrides can be prepared in such a way that the α-aminocarboxylic acid, the α-carbon atom of which is a member of a ring, is allowed to react with ethyl chloroformate and then the carbethoxy derivative is reacted with thionyl chloride, so that the corresponding acid chloride is formed, which is ethyl chloride splits off, creating the desired product. However, the route via carbobenzyloxy derivatives is to be preferred because of the easier process and because of the greater economy of the reaction. N-carbonic anhydrides can also be prepared by reacting the free aminocarboxylic acid with phosgene. The invention is illustrated by the following examples. 71.6 g (0.5 mol) of i-aminocyclohexanecarboxylic acid and 245 cm3 (0.5 M01) of 2.038 n-sodium hydroxide solution are placed in a three-necked i-1 bottle with a stirrer and two dropping funnels. While cooling this solution in an ice bath and stirring constantly, 107.7 g (0.5 M0l) carbobenzyloxychloride and 12.7 cm3 (0.5 M91) 4.076 N sodium hydroxide solution are added simultaneously from the two dropping funnels over one hour. The acid chloride addition begins a little before that of the sodium hydroxide solution, the amounts being adjusted in such a way that the addition of both substances is ended at the same time. Stirring at ice bath temperature is continued for 2 hours, after which the reaction mixture is filtered and the filtrate is extracted four times with ether. While maintaining a temperature of 0 ° by external cooling, the solution is neutralized with 49 cms of concentrated hydrochloric acid, whereupon a white precipitate forms. This is filtered off, washed with cold, distilled water until it is free of. Chlorine ion is, and dried over calcium chloride in a vacuum dryer. In this way, 72.7 g or 52% of the theoretical yield of N-carbobenzyloxy - i - aminocyclohexanecarboxylic acid with a melting point of 154.8 to 156 ° are obtained.

Analytical calculation for C15 His N 04: neutral equivalent 277.3. Found: Neutral equivalent 2754 : 276.4- 50 g (o, I8I mol) of N-carbobenzyloxy-i-aminocyclohexanecarboxylic acid be at room temperature with 19 g i (i mol) of thionyl chloride in a 2oo-cmg Destillierflas, che, the tubes containing desiccant is protected by mixed. The evolution of sulfur dioxide and hydrogen chloride begins within a minute, and complete dissolution is complete in ten minutes. The reaction mixture remains standing overnight and then has a clear, yellow-brown color. The excess thionyl chloride is removed under reduced pressure, leaving a solid product. This raw material is washed out with petroleum ether in a Buchner funnel with exclusion of moisture, 27 g (88.5% of the theoretical yield) of N-carbonic anhydride of i-aminocyclohexanecarboxylic acid being obtained.

If a purer product is to be obtained, it is taken up in 60 cm3 of boiling methylene chloride, treated with animal charcoal while it is boiling, and filtered hot. 50 cms of petroleum ether are added and the resulting solution is cooled overnight at dry ice temperature. The crystalline product is then filtered off, washed first with a mixture of 4 parts by volume of petroleum ether to 1 part by volume of methylene chloride and finally with petroleum ether alone. After drying, 17.1 g (56% of the theoretical yield) of snow-white crystals with a sharp melting point of 114.8 to 15.2 ° are obtained. Analytical calculation for C8H11N03: C 56.79; H 6.55; N 8.28. Found: C, 57.09; H 6.66; N 8.2, o.

C. Polymerization of the N-carbonic anhydride of i-aminocyclohexanecarboxylic acid. i Part of the N-carbonic anhydride of i-aminocyclohexanecarboxylic acid becomes under nitrogen heated to 160 ° in an open, tubular container. After 2 minutes starts at this temperature carbon dioxide to escape from the clear, colorless melt. After 25 minutes the Thicken liquid, and after two For hours it becomes opaque and finally solid. The polymeric product that the result is a powdery, white, solid mass which is infusible at 400 ° is. It is soluble in concentrated sulfuric acid and insoluble in 98% formic acid, in a saturated solution of calcium chloride in methyl alcohol, in 5o% lithium bromide solution, in water, in a saturated solution of calcium chloride in formic acid, in 85% strength Phosphoric acid, in 4N sodium hydroxide solution and in concentrated hydrochloric acid. This behavior With regard to the solubility, a high degree of polymerization can be seen.

When the above N-carbonic anhydride is heated to 146 °, the Formation of polymeric substances is considerably accelerated if 0.2% tetramethylenediamine be admitted.

D. Copolymer from the N-carbonic anhydrides of α-aminoisobutanoic acid and i-aminocyclohexanecarboxylic acid.

A mixture of 2 parts of N-carbonic anhydride of α-aminoisobutanoic acid and 1 part of N-carbonic anhydride of i-aminocyclohexanecarboxylic acid is heated to 160 ° under nitrogen in an open or glass-lined vessel. A clear melt is obtained almost immediately. After 2 minutes, vigorous evolution of carbon dioxide begins. After 25 minutes the liquid becomes so viscous that it begins to foam, and after 31/2 hours it becomes solid. The heating will continue for a total of 41/2 hours. The polymer obtained in this way is a white, amorphous powder that is infusible and only becomes dark in places after one minute at 400 °. It has a nitrogen content of 14.654% compared to the calculated value of 14.55%. It also has an internal viscosity of 0.13, softens at 200 degrees, then hardens and becomes infusible, and finally decomposes at 320 degrees. This polymer gives a positive biuret of a lavender tint and is soluble in chloral hydrate, chloroform, m-cresol, phenol and benzyl alcohol. It is made to swell by benzene and cyclohexane and is insoluble in tertiary butanol, concentrated hydrochloric acid, 980/4 formic acid and water. End group titrations result in an amino group content of 33oX10-0 per gram of the polymer. A molecular weight of approximately 3000 and a degree of polymerization of 27 are derived from this. Infrared absorption diagrams show the absence of diketopiperazine-like structures.

E. Mixed polymer from the N-carbonic anhydrides of d i-ß-phenylalanine and the i-aminocyclohexanecarboxylic acid.

A mixture of 3 parts each of N-carbon anhydrides of dl-ß-phenyla; lanine and i-aminocyclohexanecarboxylic acid is heated to 1q.6 ° under nitrogen. In the When the melt is clear, a strong evolution of carbon dioxide occurs immediately. To Extended foaming sets in after heating to about 150 ° for 10 minutes. the The melt then thickens and solidifies after 35 minutes. The heating is after a Total duration of 80 minutes ended. The white, powdery polymer obtained is soluble in chloroform, hot benzene and m-cresol, softens at 160 ° and has an internal viscosity of o, o9.

By pressing at 24o ° under a pressure of 35o at one obtains one clear, colorless, self-supporting film.

F. Mixed polymer from the N-carbonic anhydrides of glycine and i-aminocyclohexanecarboxylic acid. 2 parts of N-carbonic anhydride of glycine and 1 part of N-carbonic anhydride of i-aminocyclohexanecarboxylic acid are ground together in a mortar and then under nitrogen for 5 hours 121 'heated. The mixture initially sinters but does not melt. The product is Insoluble in boiling m-cresol and infusible on a copper block. A charring occurs at 32o °.

G. Mixed polymer from the N-carbon anhydrides of i-aminocyclohexanecarboxylic acid and α-aminocyclohexylacetic acid.

A mixture of equal parts of N-carbon anhydrides of i-aminocyclohexanecarboxylic acid and a-aminocyclohexylacetic acid is heated to 146 ° under nitrogen. In the clear melt almost immediately (after 1 to 2 minutes of heating) a strong evolution of carbon dioxide occurs. After heating for 10 to 15 minutes, the evolution of carbon dioxide ceases and the melt solidifies. The heating stops after one hour. The white, powdery polymer obtained is soluble in m-cresol, softens at 180 ° and has an internal viscosity of 0.09. Example 11 Production of a polymer via the N-carboxylic anhydride of i-aminocycloheptanecarboxylic acid obtained from the free acid. A solution of 3.1q. g (0.02 mol) i-aminocycloheptanecarboxylic acid in 20 cm3 (0.02 mol) 1.013 normal sodium hydroxide is placed in a cylindrical glass vessel and cooled to 0 ° in an ice bath. Phosgene is then passed into the reaction mixture for 2 minutes at a rate of 0.02 moles per minute (100% excess). A voluminous precipitate is obtained within 14 seconds, and the temperature of the reaction mixture rises to 11 °. The almost solid reaction mixture is extracted with 100 cm3 of chloroform, which dissolves a large part of the solid substance. The chloroform extract is washed with water and treated with anhydrous calcium sulfate for 30 minutes, after which the solvent is removed under reduced pressure. 0.7 g (19% of theory) of the N-carbon anhydride of i-aminocycloheptanecarboxylic acid with a melting point of 145 to 1 ° 6 ° are obtained. When recrystallizing from 10 cm3 of warm benzene to which 25 cm3 of warm petroleum ether are added, 0.35 g (10 1 / o of theory) of the purified N-carbonhydride of i-aminocycloheptanecarboxylic acid with a melting point of 146 to is obtained after cooling and allowing to stand 1q.7 °.

Analysis calculated for C9 H13 03N: C 59, oo'o / a, H 7, 15 "/ o, N 7.65%; found: C 59.0," / e, H 7.15 "/ o, N 7.79 '/ 0.

The chloroform- and water-insoluble ones remaining after the chloroform extraction Residues are taken up in 2o cm3 sodium hydroxide solution and cooled in ice, whereupon o, oi mol of phosgene per minute passed through the resulting solution for 2 minutes will. A chloroform extraction of the resulting mixture with subsequent removal of the chloroform under reduced pressure gave a further 0.2 g of the N-carbonic anhydride of i-aminocycloheptanecarboxylic acid in the form of white crystals with a melting point from 144 to 1q.5 °. The yield of N-carbonic anhydride increased to 25 "/ @ the theory.

The subsequent polymerization takes place in a manner known per se under C 02 cleavage similar to example I.

Example III Preparation of a polymer via that from the sodium salt the acid obtained N-carbonic anhydride of i-amino-x-methylcyclohexanecarboxylic acid.

15 parts of the sodium salt of i-amino-x-methylcyclohexanecarboxylic acid, which are in an open, protected from the surrounding atmosphere by drying tubes The reaction vessel is placed while cooling the vessel in a solid carbon dioxide-acetone bath covered with an excess of liquid phosgene. (The sodium salt was mixed from i-Amino-x-methylcyclohexanecarboxylic acid, which in turn consists of a mixture the methylcyclohexanone was obtained.) The reaction vessel is then placed in an ice bath, where you let it stand overnight. The excess phosgene is then distilled off. The remaining solid product is triturated with chloroform. The resulting slurry of sodium chloride in chloroform is filtered off and the chloroform from the filtrate distilled off. This is done in the absence of water and oxygen. 5.4 parts (37-1 / o, of theory) of the white N-carbonic anhydride of i-amino-x-methylcyclohexanecarboxylic acid are obtained, that sinters together at 115 to 123 ° and at 16o to 17o ° with smoke development melts. A fresh sample immersed in a 170 ° hot bath had a sharp one Melting point, decomposed with development of smoke and solidified in one minute to an opaque, white fabric.

The subsequent polymerization or copolymerization takes place in a manner known per se, with elimination of CO 2, similar to that in Examples I and II.

The present invention relates generally to manufacture of polymers or copolymers of N-carbon anhydrides of α-aminocarboxylic acids, wherein the 4-carbon atom of the carbonic anhydride or oxazolidine ring is a spiro carbon atom is, d. H. the 4-carbon atom is the one ring member common to both rings. The size of the second ring, i.e. H. of the ring outside the oxazolidine ring is insignificant, but usually has from 5 to 7 and preferably 6 limbs, while other ring sizes are rare and difficult to form. Such a ring is preferably carbocyclic, but can also be heterocyclic, in which case the heteroatoms can be oxygen, nitrogen or sulfur. It can also have substituents, such as halogen, alkyl, alkoxy and the like. Contain those in which the polymer forms Condensation does not react.

In addition to the acids mentioned in the examples, the formation of the corresponding N-carbonic anhydrides are used: 3-aminotetrahydrothiophene-3-carboxylic acid, 4-Amino-i-methylpiperidine-4-carboxylic acid, 3-aminotetrahydrofuran-3-carboxylic acid, i-amino-2-methylcyclobutane carboxylic acid, i-amino-2-methylcyclohexanecarboxylic acid, i-amino-3-methylcyclohexanecarboxylic acid, i-amino-4-methylcyclohexanecarboxylic acid, i-Amino-3, 3, 5-trimethylcyclohexanecarboxylic acid, i-aminocyclopentanecarboxylic acid, i-Aminocycloheptanecarboxylic acid and i-Amino-4-nitrocyclohexanecarboxylic acid.

The N-carbonic anhydrides used in the process according to the invention show a considerable amount compared to the known N-carbonic anhydrides of aminocarboxylic acids better heat stability. This superiority reduces the difficulty of isolation and treatment, and it enhances their usefulness as polyamide intermediates, since it passes over to the resulting polymers, although for the cleavage of the Carbon dioxide higher temperatures may be required.

The N-carbonic anhydrides according to the invention are thus valuable in the Production of polyamides and mixed polyamides by means of the evolution of carbon dioxide ongoing polymerization with one another or with other N-carbon anhydrides.

The polymers obtained according to the invention from the N-carbon anhydrides are linear condensation polyamides, characterized by repeating α-aminocarboxylic acid units. Of these, 30 to 100% of the units contain an a-carbon atom, which a member of a preferably five to seven membered and preferably carbocyclic Ringes, the ring, apart from the said a-carbon atom outside of the polymer chain.

These polymers are optionally prepared in the presence of one organic solvent by condensation polymer. sation with evolution of carbon dioxide. This is done thermally or by water, ethanol, phenols, or organic acids Amines containing amino hydrogen initiated. It runs under carbon dioxide development, wherein the reacting ingredients are all aminocarboxylic acid-N-carbonic anhydrides and to 3o to 100 percent by weight of a-aminocarboxylic acid-N-carbonic anhydrides, in which the 4-carbon atom of the N-carbonic anhydride or oxazolidine ring as the spiro carbon atom, d. H. is designed as a common link of the two rings. The spiro-N-carbonic anhydride . must make up at least 3o11 / o of the polymerizable components so that the Polymers has the specific properties of the polymers according to the invention.

The preferred method is that the selected spiroaminocarboxylic acid N-carbonic anhydride containing composition in the absence of oxygen, preferably below one inert gas, such as nitrogen or carbon dioxide, in a vessel that allows the withdrawal of Carbon dioxide allows it to be heated to a temperature at which carbon dioxide is sufficiently developed. The temperature changes a little with the different Connections, however, is usually between 70 and 200 degrees and generally above the melting point of the spiroaminocarboxylic acid N-carbonic anhydrides. The heating is with a corresponding to the gas evolution point or a little (io to 2o °) temperature above this until the evolution of carbon dioxide ceases. The reaction time can be shortened and / or the necessary temperature can be lowered, if suitable catalysts for the decomposition of the N-carbonic anhydrides, such as water, Containing ethanol, phenols, organic acids such as adipic acid or amino hydrogen Amines such as tetramethylene diamine can be used.

The polymers according to the invention show compared to the previously known Aminocarboxylic acid polyamides have a pronounced thermal stability. So join temperatures as high as 35o to 400o do not cause decomposition. Their solubility in organic solvents changes considerably and changes from high insolubility, if a single N-carbonic anhydride is used, to rather high solubility values, if the content of other amide-forming substances is increased, although it is from there are some exceptions to this generalization. The insoluble products can can be used as filler, duster for superpolyamides and pigment carriers. the Soluble products can be used to make films and man-made fibers. The interpolyamides according to the invention are in one or more of the following Medium soluble: sulfuric acid, hot benzene, chloral hydrate, tetrahydronaphthalene, below 75 ° liquid five- or six-membered alicyclic ketones, such as cyclopentanone and cyclohexanone, below 75 ° liquid halogenated hydrocarbons, such as Methylene chloride, chloroform, carbon tetrachloride, ethylene dichloride, allyl iodide, Benzyl chloride and chlorobenzene and below 75 ° liquid phenols and thiophenols, such as phenol, chlorophenol, thiophenol, resorcinol monomethyl ether and m-cresol.

The term "inner viscosity" is in the description in the meaning to understand, as described by Ewart in Advances in Colloid Science, Vol. i i, p. 2o9, is explained.

Claims (2)

PATENT CLAIMS: i. Process for the preparation of polymers from N-carbon anhydrides alicyclic a-aminocarboxylic acids, characterized in that alicyclic α-aminocarboxylic acids with phosgene or suitable derivatives thereof, e.g. B. N-carboxylic acid ester derivatives, with phosgene or thionyl chloride and the resulting N-carbonic anhydrides through Heating polymerized in a conventional manner. 2. Modification of the method according to claim i, characterized in that the N-carbonic anhydride to be polymerized is admixed with another carbonic anhydride, the amount of the second carbonic anhydride preferably not being more than 70% of the mixture. Attached publications: Reports, Vol. 39 (igo6), pp. 857 to 858; Vol. 4i ( 1 908), p. 1 72.