DE1593414A1 - Process for the production of ss-acrylamidopropionamide and polymers - Google Patents

Description

IBERLINIJ UAWiC nncru ^ · ÜONCHEN Ϊ7 Dr.-Ing. π AN 5 KUSCHRC n «*« * », smu Dipl.-Ing. HEINZ AGULAR · «·· * -" * · *;

Bank account:

Bank I. Hand ·! «. Induatri · ο «· *» Γ Dapoaitankaa «· 83 MOndian

S & * 15934 U

Talagiamm-Adfm *: Qmdralur B «riin Qi» * «tur

S 1146

Societa ¹ Per Azioni Ferrania, Milano / Italy

Process for the production of β-acrylamidopropionamide and polymers,

The present invention relates to a process for the preparation of a product with high yields which is characterized by the following structural formula: CH ₂ = CH

CO-NH-CH ₂ -CH ₂ -Co-NH ₂

and free radical polymerization products thereof which contain at least some units of the structure -CH ₂ -CH-

CO-Nh-CH ₂ -CH ₂ -CO-NH ₂

contain·

It is known that acrylamides have both free radicals as well as can be polymerized via free anions; whereby the free radical polymerization to a polymer of structure

-CH ₂ -CH-

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leads, the free anionic polymer, on the other hand, which has a predominantly poly-ß-alanino structure:

-NH-CH ₂ -CH ₂ -CO-

Breslow (j.AnwChem.Soc. T9_, 3760,1957) recognized in his fundamental work on the polymerization of acrylamide to poly-ß-alanine among the reaction products an acrylamide dimer, to which he attributed the following formula based on some analytical data:

CH ₂ = CH

CO-NH-CH ₂ -CH ₂ -CO-Nh ₂ ,

but without specifying its physical constants.

In fact, it is rather difficult to obtain in the pure state, which is consistent with what has been reported} moreover, this dimer forms among those of Bre3low in fairly small amounts (about $ 12). In addition, Breslow found that the dimer in question was in turn can be polymerized via free anions, giving a polymer that is obtained from acrylamide Poly-ß-alanine is the same.

It has now been found that it is possible by suitable selection of the reaction conditions (temperature, catalyst, solvent, concentration, reaction time, etc.) to obtain the said dimer from acrylamide with high yields (up to 45-50 $), for which the Structure CH ₂ = CH

CO-NH-CH ₂ -CH ₂ -Co-NH ₂

has been confirmed "

BATH ORIGINAL

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In addition, this product can be polymerized free-radically, both alone and in the presence other suitable ethylenically unsaturated monomer, resulting in a polymer with a comparatively high molecular weight, which at least partially Units of structure

-OH ₂ -CH-

CO-Nh-CH ₂ -CH ₂ -CO-NH ₂

contains.

The production of this dimero with high yields can be carried out using special catalysts which belong to one of the following groups: metal alkyls, such as butyllithium; Ketometallic Complexes such as the complexes of benzophenone with alkali metals (preferably with Li and K); Metallaryls, wit: e.g. lithium naphthalene. The catalysts are used in variable proportions according to the others Implementation parameters such as temperature, implementation time and monomer concentration, however, they are preferably used in amounts of 0.005 to 0.05 moles per mole of acrylamide used. The monomer concentration can vary over wide ranges; however, concentrations have increased

Weight £
around 10-15 * proven to be cheap.

The reaction is carried out in the usual inert organic Solvents (solvents with an ethereal character are particularly advantageous,

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such as dioxane and tetrahydrofuran), at temperatures in the range of 0-100 °, and for times in the range of 10 minutes up to 48 hours. It turned out to be particularly advantageous to carry out the reaction in dioxane, in which the dimer is relatively soluble in the heat, but not soluble in the cold.

The various conversion parameters are closely related to one another and are all important in order to obtain the dimer in high yields. Therefore, the higher the temperature, the shorter the reaction time; in fact, since it appears from the observations made that the reaction is gradual, it is appropriate, after the temperature has been set, to carefully check the reaction time and to stop the reaction when a high dimer concentration is reached thereby preventing further growth into polymers. If we introduce in this V. ^r else the reaction with a suitable solvent and catalyst, such as dioxane and butyl lithium shown in the above concentrations at 6O ⁰ C, a dimer yield is obtained of 30-35 $, when the reaction is interrupts after 10-15 minutes. If the reaction time is extended to 10 hours, the yield of dimer drops to less than 10 $.

The dimer yield can be increased to $ 45-50, while at the same time the need for careful

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Checking of the time-temperature factors switched off by carrying out the reaction with the system just described at room temperature for 24-30 hours. In this particularly favorable case, the dimer, which is sparingly soluble, separates from the reaction medium from, and thereby limits the possibility of growth into the polymer.

In the reactions shown here, in addition to the dimer, other oligomers and poly-ß-alanines are also formed low molecular weight. When carrying out the reaction in the heat, since oligomers that are formed are higher than that Dimers and poly-ß-alanines of low molecular weight are insoluble, can be obtained by filtration of the hot Reaction mixture the dimer, which gradually crystallizes out quite pure as the filtrate cools down slowly, easily separated from the other by-products. The yield is about $ 30-35 »calculated on acrylamide.

If the reaction is carried out at room temperature, the yield of dimer rises to $ 45-50. By filtration of the reaction mixture to obtain a mixture of the dimers, other oligomers and poly-beta-alanine with a low, molecular weight, from which the dimers can be easily recovered by extraction with hot dioxane.

It has also been found that this dimer polymerizes together with suitable monomers and mixed-polymerizes via free radicals, with products forming

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result in a comparatively high molecular weight, all or part of the units of the structure -CH ₂ -CH-

CO-NH-CH ₂ -GH ₂ -Co-NH ₂

contain.

The polymerization can be carried out in the usual solvents such as water, methanol, dioxane, dimethylformamide etc. using any of the usual free radical generating catalysts such as potassium persulphate (with or without bisulphite as accelerator), organic peroxides, hydrogen peroxide, Hydroperoxides, Azokaialysatoren, and at temperatures in the range of room temperature to 100 ⁰ C works.

UV radiation polymerization has proven to be beneficial to carry out the dimer in methanol at room temperature, using as a catalyst Azobis-isobutyronitrile or 4,4'-azobis-cyanopentanoic acid used, and to carry out the copolymerization in methanol at reflux with the same catalysts. Usable mixed monomers include: acrylamide, methacrylamide, vinyl acetate, acrylic and methacrylic acid, acrylate ester, Vinyl pyrrolidone, vinyloxazolidone, maleic acid imide, acryloyl pyrrolidone, acryloyl caprolactam, styrene potassium sulfate etc.·

The following examples are intended to provide more detailed information without limiting the scope of the invention in any way.

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example 1

300 g of acrylamide, freshly recrystallized from chloroform and thoroughly dried, and 2400 ml of dry dioxane are placed in a 3 liter flask (with a shark). With vigorous stirring with an electromagnetic stirrer, 75 ml of butyllithium (as a 1.6 M solution in η-hexane) are added under an atmosphere of pure dry nitrogen at room temperature. The flask is sealed and heated for 15 minutes at 6O ⁰ C, then the solid formed under vacuum alfiltriert hot. The filtrate is left to stand for 24 hours, whereupon the β-acrylamidopropionamide, which is the acrylamide dimer, crystallizes out. The product is filtered off, washed with a little dioxane and then with a little ether and dried under vacuum.

Yield: 90 g = 30 ^ of the theoretical value. Melting point: 143-145 ⁰ C; after recrystallization 145-148 ⁰ C,

., - calculated 19.71

C _fi H _1n NpOp? ÖN content of double bonds

^N found 19.51 fertilize = 98.5 ^

Osmometric molecular weight (determined with a vapor pressure meter) = 140.5; (theoretical 142.1).

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The infrared spectrum of the product has the following characteristics: absorption at 950 and 980 cm ", which can be attributed to the double bond; absorption at 1555 cm, characteristic of the 2nd band of the secondary amides; absorption at 1635 cm", characteristic of the 2nd band .Band of the primary amides, and finally absorption at 3300 cm " ¹ in" NH-stretching "~ Eerefch,

Example 2

200 g of acrylamide, freshly crystallized from chloroform and thoroughly dried, and 1600 ml of dioxane, dried over calcium chloride and distilled over potassium benzophenone, are placed in a 1 liter flask (with a neck) 25 ml of a 1.6 M solution of butyllithium in hexane are added to an atmosphere of pure dried nitrogen. The flask is closed tightly and the contents are allowed to stand for 24 hours, stirring occasionally. The pest body which separates out is filtered off, washed with a little dioxane and ether and dried. Yield: 160 g; <γ> sp / c = 0.027 for a 1 $ 1m solution in NaNO ₃ at 30 ⁰ C.

90 g of the product thus obtained are repeatedly extracted with boiling dioxane; the extracts are

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agrees, pressure concentrated at 3O ⁰ C and 20 mm Hg to a small volume, and is withdrawing product is filtered off and recrystallized from dioxane to give 42 g (yield 42 $, calculated based on the initial amount of acrylamide) Q-Acrylamidopropionamid obtained with a melting point of 148 ⁰ C.

The residue after extraction of the dimer has a '> l sp / c = 0.080, as measured on a # 1 solution in 1m NaNO ₃ at 30 ⁰ C.

Example 3

In this example, the procedure of Example 2 is repeated, but the butyllithium is replaced by an equivalent proportion of lithium benzophenone in dioxane.
Yield of dimer: $ 40>,

Example 4

In this example the procedure of Example 2 is repeated, but replacing the butyllithium with an equivalent Replaced proportion of lithium naphthalene in tetrahydrofuran, and the implementation time extended to 36 hours. Yield of dimer: 38.5 #.

Example 5

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ORIGINAL INSPECTED

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40 g of Q-acrylamidopropionamide and 400 ml of dry Methanol is added the solution is degassed under vacuum, then 0.04 g (!, a'-azobis-isobutyronitrile are added, and then a 4 hour UV irradiation is carried out. After decanting off the methanol, the Polymer, which has deposited as a soft, viscous mass, dissolved in 200 ml v / water; the solution will be saturated with acetone and the polymer obtained by precipitation in acetone.

The precipitate is filtered off, washed with a little acetone and dried.

Yield: 38 g = 95 ^ of theory, of a white powder, Easily soluble in water, with a [^] = 0.62 dl / g in

1m NaNO ₃ at 30 ⁰ C.

^, calculated 19.71 ^ found 19.02

Example 6

In a flask equipped with a mechanical cooler Stirrer and nitrogen inlet and outlet tubes 42.6 g of β-acrylamidopropionamide, 25.8 g of distilled Vinyl acetate and 684 ml of dry methanol were added. The mixture is refluxed for 5 minutes, then 1 $ benzene peroxide was added and the whole thing for 4 hours refluxed. The flask is cooled in ice, the

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Methanol is decanted and the precipitated polymer is washed with a little methanol, then with ether and dried under vacuum.
Yield; 40 g = $ 58.5 ^ N = 16.48.

Example 7

- In a flask equipped with a reflux condenser and mechanical stirrer, 7g ß-acrylamidopropionamide, Put 1 ml of distilled ethyl acrylate in 125 ml of methanol.

The solution is refluxed for 5 minutes; 0.1 go ^ a'-Azobisisobuty "onitril are added and it is boiled again for 6 hours at reflux, then cooled and the methanol abdtikantiert _o A \ A ^ e ~ · different polymer is collected, dissolved in 3 ml of v / ater and 4 ml of acetone are dissolved, and the solution is precipitated in a 1: 1 mixture of acetone-methanol. The precipitate is washed three times with acetone and dried under vacuum.

Yield: 6 g of water-soluble product. N content; £ 16.31.

. '■ - Claims -

BATH ORIGINAL 909885/1585

Claims (1)

j ¹ : \ te η ta η s ρ r ü ch e. : 1o method of manufacturing a product with
high yields of the formula . Co-NH-CH ₂ -CH ₂ -CO-NH ₂ , characterized in that treated under practically anhydrous conditions acrylamide with an organometallic compound which is a metal alkyl, metal aryl or a
ketometallic complex can be _o 2. Method of making a product with
high yield of the formula CHp = CH CO-NH-CH ₂ -CH ₂ -CO-Nh ₂ , characterized in that under practically anhydrous conditions acrylamide with an organometallic
Compound, which can be a metal alkyl, ketallaryl or a keto-metallic compound, at a temperature im
Range of 0-100 C, treated in an inert organic solvent, the inert organic solvent being dioxane » 3ο method of making with high yield one. Product of the formula CH ₂ = CH - CO-Nh-CH ₂ -CH ₂ -CO-NH _2,. characterized in that under practically water 9 0988 5/158 5 _BAD 1B93414 free conditions acrylamide with a Compound at a temperature in the range of C'-1. (O 0, treated in an inert organic solvent, v / o at the organometallic compound n ~ butyllithiuE i and that inert organic solvent dioxane is * 4. The method according to claim ^x , cKduroh, that there is used as the organometallic compound lithium-benzene-ophenon '. 5ο method according to claim ^, d-i characterized by, that as an organic metal compound, lithium naphthalene used. 6. Polymers or Kischpol ^ erin'-ite, characterized in that they are wholly or partially ^ inunity. the structure - - ' CO-NH-OK ₂ -CH ₂ -GO-IIh ₂ and which have been produced by polymerisation or polymerisation of the product according to claims 1 to 5 in the manner of a polymerisation initiator which produces free radicals _e . 909 8 8 S / 15 8 5