RU2148059C1 - Method of preparing nitrogen-containing heterocyclic cellulose derivatives - Google Patents

Abstract

FIELD: paper-and-pulp industry. SUBSTANCE: method consisting in modifying cellulose derivatives by treating it with nitrogen- containing compound, washing resulting product with water, and drying is distinguished by using cyanoethylcellulose as starting cellulose derivative and sodium azide as nitrogen-containing compound. EFFECT: reduced price of preparation technology. 2 cl, 1 tbl

Description

 The invention relates to methods for producing derivatives of cellulose, and in particular to methods for producing nitrogen-containing heterocyclic derivatives, which are used, inter alia, as biologically active compounds (Rogovin Z. A., Galbraikh L.S. Chemical transformations and modification of cellulose. M .: Chemistry , 1979, 206 p.).

 A known method for the synthesis of 2,3-di- (5-azino-1,2,4-triazole) - cellulose (A.S. NRB N24468 (1978) 2,3-Di- (5-azino-1,2,4 -triazole) -cellulose and the method after receiving the flight // D. G. Dimitrov, K.D. Dimov, B.A. Dimitrov.- RZhKhim., 1982 - 50 92 P), which is based on the interaction of DAC with nitrogenous heterocyclic amines . DAC was obtained by periodically oxidizing powdered cellulose.

 A known method for the synthesis of 2,3-diazindiphenan-trolincellulose, taken as a prototype (A.S. NRB N24123 (1978) 2,3-diazindiphenatrolincellulose and the method after receiving // D. G. Dimitrov.- RZhKhim., 1982 -6 56 P). The basis of this method is the oxidation of powdered cellulose with sodium periodate to dialdehyde cellulose (DAC), and then the reaction of 5-amino-1,10-phenanthroline with aldehyde groups of oxidized cellulose.

 The main disadvantage of this method is the use of DAC as the main reagent, the synthesis of which requires the use of sodium periodate, an expensive and toxic compound.

 The present invention is to develop a method that will simplify and reduce the cost of technology for producing nitrogen-containing heterocyclic derivatives of cellulose (AGPC).

 The synthesis of AGPC based on the reaction of sodium azide with cyanoethyl cellulose (CEH), the production of which has been mastered in industry, as well as the optimal technological parameters of the reaction: time - 1-2 hours, the use of catalytic additives - lithium and ammonium chlorides, allow to obtain a technical result, which is causally -consequential connection with the essential features of the invention.

 The essential features of the invention include: the production of AGPC based on the reaction of cyanoethyl cellulose with sodium azide for 4-5 hours in the presence of lithium or ammonium chloride additives.

AHPC was obtained by the following sample. CEZ - a pilot industrial production of VNIISS (Vladimir), was purified from a DMF solution by reprecipitation in water. The solution was pre-filtered on a large-pore glass filter No. 1. The precipitate was washed on the filter with distilled water, ethanol, diethyl ether, and dried at T = 45-50 ^° C to constant weight. The degree of substitution (C3) for nitrile groups, calculated according to elemental analysis for nitrogen, was 2.4. The degree of polymerization, determined by the viscometry of solutions in methylene chloride with methanol, at a ratio of 9: 1, was 550.

 Sodium azide - grade Ch, GOST 66-85. The content of the main substance is not less than 99%.

 AGPCs were obtained by treating CEH with sodium azide without and in the presence of lithium and ammonium chlorides in solutions of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). As the main starting components for the production of AGPC, the proposed method can be any cyanide-derived cellulose and alkali metal azides. The choice of CEH and sodium azide is explained by their availability for preparative synthesis and the possibility of industrial development of the process. Sodium azide was taken from the calculation of 3 mol per 1 mol of cyano groups of the CEEC, taking into account the degree of substitution of the samples of the CEEC. The solution was heated in a sand bath at the boiling point of the solvent. Reaction time: 1, 5, and 10 hours. 10 minutes after the start of boiling from solutions without additives and with the addition of lithium chloride, modified CEH samples precipitated, which was decanted on a glass filter after the reaction time. When using ammonium chloride additives, a precipitate did not form, and after the end of the reaction time, the solution was poured with stirring into a 10-15-fold volume of distilled water, and the resulting product precipitated.

In the next series of experiments, the reaction was carried out by slightly changing the conditions — in a water bath at 98-99 ^o C and with a mechanical stirrer with vigorous stirring of the reaction mixture for 4, 5 and 10 hours. In this case, the precipitate precipitated 3 hours after the start of the reaction .

After decanting, the precipitate was washed thoroughly with distilled water until a negative reaction to azides. Next, extraction was carried out with alcohol and ether in a Soxhlet apparatus. The resulting product was dried at room temperature, then at 40 - 45 ^o C to constant weight. The yield and analysis results of the obtained compounds depending on the synthesis conditions are given in the table.

 The table shows that the use of lithium and ammonium chloride additives increases the C3 of the compounds obtained. The optimal reaction time is 4-5 hours, since a further increase in the reaction time does not lead to a significant increase in C3, but reduces the yield of the final product.

 The structure of the products obtained as a result of the reaction of the CEC with sodium azide was identified on the basis of IR spectroscopy and elemental analysis.

 Elemental analysis was performed on a Carlo Erba - 1106 elemental analyzer according to the Carlo Erba method, which provides an accuracy analysis for nitrogen of + 0.05%. IR spectra were recorded on a Specord-M80 IR spectrograph.

где Cell - элементарное звено макромолекулы целлюлозы, а Cell - OCH₂CH₂CN - элементарное звено исходной цианэтилцеллюлозы.The resulting compound, based on the obtained elemental analysis and IR spectroscopy, can be identified as tetrazole-5-ethyl cellulose. In this case, the reaction proceeds according to the following scheme:

where Cell is the elementary unit of the cellulose macromolecule, and Cell is OCH ₂ CH ₂ CN is the elementary unit of the initial cyanoethyl cellulose.

 It should be noted that the above scheme is somewhat arbitrary, because at C3 = 2.4, that is, on average 2.4 cyanethyl groups per elementary unit, the initial cyanethyl cellulose can have both one-, two- and three-substituted units, and the final product, in turn, can contain not only one , but also two and three heterocycles per elementary unit.

 Example 1

In a three-necked flask equipped with a thermometer and a water-cooled reflux condenser, 200 ml of DMF were charged and 5 g of cyanoethyl cellulose was dissolved in it. 3 g of sodium azide and 1 g of ammonium chloride were added. The flask was heated in a sand bath at a boiling point of DMF - 151-152 ^o C. Heating was carried out for 1 h. The resulting product was precipitated in cold (T = 5-10 ^o C) water, washed after decanting on the filter with a large amount of distilled water until absent there are traces of sodium azide, then washed with alcohol and diethyl ether. The resulting product was dried at room temperature, then at 40 - 45 ^o C to constant weight and analyzed (table, p. 1).

 Example 2

In a three-necked flask equipped with a thermometer and a water-cooled reflux condenser, 200 ml of DMF were charged and 5 g of cyanoethyl cellulose was dissolved in it. 3 g of sodium azide and 1 g of lithium chloride were added. The flask was heated in a sand bath at a boiling point of DMF - 151-152 ^o C. Heating was carried out for 5 hours. The precipitate was washed after decanting on the filter with a large amount of distilled water until there was no trace of sodium azide in it, then it was washed with alcohol and diethyl ether. The resulting product was dried at room temperature, then at 40 - 45 ^o C to constant weight and analyzed (table, p. 8).

 Example 3

In a three-necked flask equipped with a thermometer, a water-cooled reflux condenser and a stirrer, 200 ml of DMSO was charged and 5 g of cyanethyl cellulose was dissolved in it. 3 g of sodium azide and 1 g of lithium chloride were added. The flask was heated at T = 98-99 ^o C in a water bath, the reaction mass was intensively stirred. Heating was carried out for 4 hours. The precipitate formed was washed after decanting on the filter with a large amount of distilled water until there was no trace of sodium azide in it, then it was washed with alcohol and diethyl ether. The resulting product was dried at room temperature, then at 40 - 45 ^o C to constant weight and analyzed (table, p. 10).

 Example 4

In a three-necked flask equipped with a thermometer, a water-cooled reflux condenser and a stirrer, 200 ml of DMF were charged and 5 g of cyanoethyl cellulose was dissolved in it. 3 g of sodium azide and 1 g of ammonium chloride were added. The flask was heated at T = 98-99 ^o C in a water bath, the reaction mass was intensively stirred. Heating was carried out for 4 hours. The precipitate formed was washed after decanting on the filter with a large amount of distilled water until there was no trace of sodium azide in it, then it was washed with alcohol and diethyl ether. The resulting product was dried at room temperature, then at 40 - 45 ^o C to constant weight and analyzed (table, item 13).

 Example 5

In a three-necked flask equipped with a thermometer, a water-cooled reflux condenser and a stirrer, 200 ml of DMF were charged and 5 g of cyanoethyl cellulose was dissolved in it. 3 g of sodium azide and 1 g of lithium chloride were added. The flask was heated at T = 98-99 ^o C in a water bath, the reaction mass was intensively stirred. Heating was carried out for 10 hours. The precipitate was washed off after decanting on the filter with a large amount of distilled water until there were no traces of sodium azide in it, then it was washed with alcohol and diethyl ether. The resulting product was dried at room temperature, then at 40 - 45 ^o C to constant weight and analyzed (table, p. 21).

 As follows from the data presented, the synthesis of nitrogen-containing heterocyclic derivatives of cellulose based on the reaction of cyanethyl cellulose and sodium azide allows one to obtain AGPC in one stage, without preliminary oxidation of cellulose to DAC and to abandon the use of toxic and expensive reagents - periods, and to use components whose production has been mastered in industry. At the same time, the optimal reaction time is 4-5 hours, and the use of additives of ammonium chloride and lithium chloride increases the C3 of the final product by heterocycles.

Claims (2)

 1. A method for producing nitrogen-containing heterocyclic derivatives of cellulose, comprising modifying a cellulose derivative by treatment with a nitrogen-containing compound, washing the resulting product with water and drying, characterized in that cyanoethyl cellulose is used as the initial cellulose derivative, and sodium azide is used as the nitrogen-containing compound.  2. The method according to claim 1, characterized in that during processing using additives of lithium chloride or ammonium chloride, and the treatment is preferably carried out within 4 to 5 hours

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