RU2152402C1 - Process for preparing azomethyne derivatives of cellulose - Google Patents

Abstract

FIELD: cellulose derivatives production. SUBSTANCE: aldehyde groups of ozonation-prepared microcrystalline cellulose are condensed for 2-3 hr at 97-100 C with 1-2 moles of a cellulose-modifying amino compound per 1 mole of aldehyde groups until degree of substitution 5.8 to 9.3 is attained. Product contains substituted unit with following structure:

Description

 The invention relates to methods for producing derivatives of cellulose, namely nitrogen-containing derivatives of cellulose. These compounds are used as biologically active compounds (Rogovin Z.A., Halbraich L.S. Chemical transformations and cellulose modification. - M.: Chemistry, 1979, 206 pp.).

 A known method for the synthesis of 2,3-diazindifenatrolin-cellulose, which is based on the oxidation of powdered cellulose with sodium periodate to dialdehyde cellulose (DAC), and then the reaction of 5-amino-1,10-phenatrolin with aldehyde groups of oxidized cellulose (A.S. NRB N 24123 (1978) 2,3-Diazindiphenatrolin-cellulose and the method for receiving // DG Dimitrov. - RZhKhim., 1892 - 6 t. 56 P).

 A known method for the synthesis of 2,3-di- (5-azino-1,2,4-triazole) -cellulose (A.S. NRB N 24468 (1978) 2,3-Di- (5-azino-1,2, 4-triazole) -cellulose and the method for receiving //D.G. Dimitrov, K.D. Dimov, B.A. Dimitrov.- RZhKhim., 1982 - 50 92 P.), taken as a prototype. This method is also based on the interaction of DAC with nitrogenous heterocyclic amines. DAC was obtained by periodically oxidizing powdered cellulose to shorten the duration of the process.

 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 objective of the present invention is to develop a method that will simplify and reduce the cost of technology for producing azomethine derivatives of cellulose, reduce the duration of the process.

 The use of ozonized microcrystalline cellulose (MCC), which contains aldehyde groups in an amount up to 6 mmol / g, as well as optimal technological parameters: the reaction time is 2-3 hours, the ratio of the starting reagents is 1 mol of the amino compound per mole of aldehyde groups of cellulose, allows to obtain technical a result that is in a causal relationship with the essential features of the invention.

где R - остаток аминосоединения, выбранного из группы, включающей 5-амино-1,2,4-триазол, 4-амино-1,2,4-триазол, α- аминоянтарную кислоту, α- аминопиридин, аминобензол.The essential features of the invention are: treatment of microcrystalline cellulose obtained by ozonation, condensation at a ratio of 1-2 mol of the amino compound per 1 mol of cellulose aldehyde groups for 2-3 hours to a degree of substitution of 5.8 to 9.3 and obtaining the azomethine derivative with the following substituted formula link:

where R is the residue of an amino compound selected from the group consisting of 5-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, α-amino succinic acid, α-aminopyridine, aminobenzene.

 MCCs were obtained according to the method described in [V.A. Demin, V.V. Shereshovets, G. Ya. Osipova, N.N. Kabalnova. Cellulose depolymerization during ozonation // Journal prikl. chemistry. - 1993. - T. 66, no. 11. - S. 2562-2567].

Ozonation was carried out at 20-22 ^o C in a thermostatically controlled bubble-type reactor with a volume of 200 cm ³ . 150 cm ^{3 of} distilled water, 2 g of sulphate bleached pulp from a mixture of hardwood according to GOST 28172-89E were loaded into the reactor. The ozone-oxygen mixture was supplied at a rate of 3-4 dm ³ / h.

 Azomethine cellulose derivatives were prepared as follows.

When heated to 97-100 ^o C, a powder of MCC obtained by ozonation of bleached hardwood pulp (containing aldehyde groups of 6.1 mmol / g or 9.84 aldehyde groups per 100 glucopyranose units) was added to the solution of amino compounds at the rate of 1 mol of aldehyde groups per 1 mol of amines. The content of aldehyde groups in the initial MCC and the final product was determined by titration (A. V. Obolenskaya, V. P. Shchegolev, G. L. Akim, E. L. Akim, N. L. Kossovich, I.Z. Emelyanov. Practical work in chemistry of wood and cellulose. Edited by V.M. Nikitin. M., Lesn. prom., 1965. - 411 p.).

 The structure of the final products and the degree of substitution (S3) were identified based on the data of IR spectroscopy, elemental analysis, and comparison of the quantities of the initial and aldehyde groups remaining after the reaction.

Example 1
In a three-necked round-bottom flask equipped with a thermometer, a mechanical stirrer and a reflux condenser, a suspension of 5-amino-1,2,4-triazole was dissolved in the calculated amount of water at a temperature of 60-70 ^o C. The solution was heated to 97-100 ^o C and the MCC powder was added to it, at the rate of 1, 2 and 3 moles of aldehyde (CHO-) cellulose groups per 1 mol of 5-amino-1,2,4-triazole.

The flask was placed in a boiling water bath and the reaction mixture was kept under vigorous stirring for 3 and 5 hours. At the end of the exposure, the resulting product was filtered through a cloth filter on a Buchner funnel from a hot solution that did not interact with MCC 5-amino-1,2 , 4-triazole, and repeatedly washed in a glass with stirring with warm (50-60 ^o C) water until there are no traces of 5-amino-1,2,4-triazole in it. The resulting product was dried at a temperature of 102-104 ^o C to constant weight and analyzed.

 The specific conditions for obtaining a number of powder samples of azomethine derivatives of cellulose are given in the table.

Example 2
In a three-necked round-bottomed flask equipped with a thermometer, a mechanical stirrer and a reflux condenser, a suspension of 4-amino-1,2,4-triazole was dissolved in the calculated amount of water at a temperature of 60-70 ^o C. The solution was heated to 97-100 ^o C and the MCC powder was added to it, at the rate of 1, 2 and 3 moles of aldehyde (CHO-) cellulose groups per 1 mol of 4-amino-1,2,4-triazole.

The flask was placed in a boiling water bath and the reaction mixture was kept under vigorous stirring for 3 and 5 hours. At the end of the exposure, the resulting product was filtered through a cloth filter on a Buchner funnel from a hot solution that did not interact with MCC 4-amino-1,2 , 4-triazole, and repeatedly washed in a glass with stirring with warm (50-60 ^o C) water until there are no traces of 4-amino-1,2,4-triazole in it. The resulting product was dried at a temperature of 102-104 ^o C to constant weight and analyzed.

Example 3
In a three-necked round-bottom flask equipped with a thermometer, a mechanical stirrer and a reflux condenser, a portion of α-amino-succinic acid was dissolved in the calculated amount of water at a temperature of 85-95 ^o C.

The solution was heated to 97-100 ^o C and the MCC powder was added to it, at the rate of 1, 2 and 3 moles of aldehyde (CHO-) cellulose groups per 1 mol of amino acid.

The flask was placed in a boiling water bath and the reaction mixture was kept under vigorous stirring for 3 and 5 hours. At the end of the exposure, the resulting product was filtered through a cloth filter on a Buchner funnel from a hot solution that did not interact with the MCC of the amino acid and was washed repeatedly in a glass with stirring with hot (70-80 ^o C) water until there are no traces of α-amino-succinic acid in it. The resulting product was dried at a temperature of 102-104 ^o C to constant weight and analyzed.

Example 4
In a three-necked round-bottom flask equipped with a thermometer, a mechanical stirrer and a reflux condenser, a portion of α-aminopyridine was dissolved in the calculated amount of water at a temperature of 60-70 ^o C.

The solution was heated to 97-100 ^o C and the MCC powder was added to it, at the rate of 1, 2 and 3 moles of aldehyde (CHO-) cellulose groups per 1 mol of α-aminopyridine.

The flask was placed in a boiling water bath and the reaction mixture was kept under vigorous stirring for 3 and 5 hours. At the end of the exposure, the resulting product was filtered through a cloth filter on a Buchner funnel from a hot solution that did not interact with the α-aminopyridine MCC and was washed many times. in a glass with stirring with hot (60-70 ^o C) water until there are no traces of α-aminopyridine in it. The resulting product was dried at a temperature of 102-104 ^o C to constant weight and analyzed.

Example 5
In a three-necked round-bottom flask equipped with a thermometer, a mechanical stirrer and a reflux condenser, a weighed amount of aminobenzene (aniline) was dissolved in the calculated amount of water at a temperature of 50-60 ^o C.

The solution was heated to 97-100 ^o C and the MCC powder was added to it, at the rate of 1, 2 and 3 moles of aldehyde (CHO-) cellulose groups per 1 mol of aminobenzene.

The flask was placed in a boiling water bath and the reaction mass was intensively stirred for 3 and 5 hours. After this, the resulting product was filtered through a cloth filter on a Buchner funnel from a hot solution of aminobenzene (aniline) that did not interact with MCC, and was washed many times in a glass at stirring with hot (60-70 ^o C) benzene until there is no aminobenzene (aniline) in it. The resulting product was dried at a temperature of 102-104 ^o C to constant weight and analyzed.

 The production conditions and properties of azomethines are presented in the table. As follows from the presented data, the use of MCC obtained using ozonation allows one to obtain azomethine derivatives of cellulose without the use of toxic and expensive reagents - periodates.

Claims (1)

A method of producing azomethine cellulose derivatives by condensing the aldehyde groups of the starting cellulose with a cellulose-modifying amino compound at 97-100 ^° C, characterized in that microcrystalline cellulose obtained by ozonation is used as the starting cellulose, and the condensation is carried out at a ratio of 1 to 2 moles of amine compound per 1 cellulose groups for 2 to 3 hours to a degree of substitution from 5.8 to 9.3 and obtain azomethine derivative with the following formula of the substituted unit:

where R is the residue of an amino compound selected from the group consisting of 5-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, α-amino succinic acid, α-aminopyridine, aminobenzene.

Images