SU1724305A1 - Method of producing carboxyorganosilica sorbents - Google Patents

Abstract

The invention relates to the production of sorbents for liquid chromatography containing carboxyl groups on the surface. The aim of the invention is to accelerate the process of obtaining the sorbent while maintaining the degree of surface amino acid grouping. To achieve the goal, aminopropyl silica is treated with dicarboxylic acid so that 1 mol of aminopropyl groups comes in 1 , 5-2.5 mol of dicarboxylic acid. The treatment is carried out in vacuum at 100-220 ° C for 20-40 minutes, table 2. about $

Description

The invention relates to chromatography, in particular to the preparation of modified silica sorbents, which are used in chromatography, as well as to immobilize amino compounds.

A known method for the preparation of carboxyorganic silica (CEC), which involves the processing of y-aminopropylsilica (APC) with succinic anhydride according to the scheme

The closest effect to be achieved is the method of producing COCs, which consists in acylation of the AIC with chloroanhydrides of dicarboxylic acid esters (succinic, maleic, phthalic), followed by hydrolysis according to the scheme

IAANH CECO-Y-COOR IAA

NHCO-X-COOR

2NHCE -ROH

1g

NHCO-X-COOH

vj

4 od

ABOUT

cl

benzene and three times with dichloromethane and. dried for 12 hours under vacuum at 100 ° C. Hydrolysis of the complex-naphtha groups is carried out in a mixture of 2NHC1 and ethanol (1: 1 by volume) with stirring and boiling. The mixture is cooled, filtered, washed three times with a mixture of water - ethanol (1: 1) and three times with water and dried for 12 hours under vacuum at 100 ° C. The degree of acylation of aminopropyl groups of APC is 60-70%. Due to the simultaneous presence on the surface of amino and carboxyl groups, the resulting COCs have both amionic and cation-exchange properties. sorbents about the duration of the process, taking into account all operations Avlet 1.5 suts

The disadvantages of this method are the duration and multistage (as well as the need to use complex and unstable acylating reagents) „

The aim of the invention is to accelerate the process while maintaining the degree of acylation of amino groups of at least 50%.

According to the method for producing COCs, involving the interaction of the APC with an acylating reagent when heated, a dicarboic acid containing at least two carbon atoms in the hydrocarbon radical is taken as the acylating reagent, and 1.5 to 1 mol of aminopropyl groups. 2.5 mol of dicarboxylic acid, and heating is carried out in vacuum at 160-2206С for 20-40 minutes. The process chemistry is described by the following scheme:

(CH2) nCOOHj | vNNHCO (CH2) nCOOHJ

When implementing the method, dicarboxylic acids are used (amber, ,,. Glutaric, adipic, pimelic, sebacin) „

Used reagents are given in table, 1 o

Oxalic acid and malonic acid are not

50

they are used because at temperatures above 150 ° C their decomposition is observed (decarboxylic).

AIC on the basis of Silohrom-120 wide-pore silica gel. Silica is placed in a molybdenum glass vacuum reactor. After pre-evacuation for Q, 5 hours at 150 ° C, add to the reactor

Q

0

five

0 s

0

,

0

five

Y-aminopropyltriethoxysilane: Silanization was carried out at 140-160 ° C for 2 hours. Then the unreacted silane and volatile reaction products were removed by vacuum at the same temperature. The concentration of the grafted aminopropyl groups was 0.29 mmol / g. The process of producing COCs is carried out in a cylindrical molybdenum glass reactor (diameter 4 cm, length 20 cm) equipped with a conical section, through which the reagents are loaded, connected to a vacuum system (a trap cooled by liquid nitrogen and a back-up pump ZNVR-1D ) and unloading the product of modification (COC) „

APC and dicarboxylic acid are loaded into the reactor for 1 mol of aminopropyl groups of APC. 1.5-2.5 mol of dicarboxylic acid are taken. After evacuation, the reactor is heated at 160-220 ° C for 20-40 minutes.

The quality control of the modification products is carried out as follows. For semi-qualitative quality assessment, the method of IR spectroscopy is used. In the IR spectra of COCs, for which the degree of acylation of amino groups is more than 50%, the intensity of the absorption bands of the stretching vibrations of the Cr.o carboxyl groups (1725- 1740 ci) and amide bonds (1665–1675 cm) differ slightly, in addition, there are bands of amide bonds (1560–1575 of somewhat lower intensity) In the IR spectra of COCs with a small degree, acylation and significant soda By neighing adsorbed dicarboxylic acids, the intensity of the absorption bands of carboxyl groups significantly (more than two times) exceeds the intensities of the amide bands (and QNW). C To estimate the acylation degree of the amino groups of the APC, elemental analysis data (for carbon) is used, comparing them with of the original AIC “Calculation of the number of mmol of grafted dicarboxylic acid per 1 g of silica is made according to the formula

N G / 1,2 RS.

where PC is the amount of carbon,%, according to the analysis, minus the carbon content in the initial aminopropylsilica;

nc is the number of carbon atom in the graft group ..

The degree of conversion (SP,%) of the aminopropyl groups is determined by the form N L SP y Tg - SO, where NAn is concentrated

aminopropyl group

Example 1 “In a molybdenum glass reactor, 10 g of APC o (U-aminopropyl-silochrome) with an amino group concentration of 0.29 mmol / g and 0.68 g (5.8 mmol) of succinic acid are placed. The reactor is connected to a vacuum source (foreline pump) through a trap cooled with liquid nitrogen 15 and the lower zone of the reactor containing reagents is placed vertically in a cylindrical furnace heated to 190 ° C. The reactor is heated at a constant pumping of water vapor generated during acylation “Excess succinic acid condenses in the upper (cold) reactor zone in the form of a dense crust, without contaminating the modifying product (COC)“ After 30 minutes of heating, the reactor is removed from the furnace, cooled and disconnected from the vacuum system 0 The product is discharged and weighed (10.5 g), the weight gain is about 0.5 g. According to elemental analysis (for carbon), the degree of acylation of the aminopropyl groups of the original APC is 80%. In the IR spectrum of the obtained COC, it is observed the effect at this increases

Examples 6-9, Received

20

25

thirty

Example 1, except for changing the temperature at which the acylation is carried out. If the rate of the tour is within the proposed shaft (examples 6 and 7), then the target is reached. At a temperature below the preferred interval (example 8), the acylation of amino groups lower than what is known, and if the temperature is in (Example 9), then decarboxylation of grafted with succinic acid, which is expressed in yellowing of the product, is observed.

Examples 10-13. Proceedings of example 1, except for the fact that the acylation time is changed; the time of acylation is within the span of the interval (examples 10 and that goal is achieved. If the time of the lithium is shorter than the offered shaft (example 12), then the product contains a significant amount of adsorbed succinic acid when stabilizing, it is lower than that of the known. Increasing the duration of acylir or more than the proposed interval (Example 13) does not lead to an increase in the degree of acylation.

Examples 14-26. In example 14-26 come in examples 1-13

There are v (COOH), (amide I) 35 bands, except that in quality and &

, Mts (amide II), respectively, at 1740, 1675 and 1565 .. The duration of the process, taking into account all operations, is 1.5 hours.

Data on the acylation mode and the degree of acylation are given in the scoreboard 2 "

Examples 2-5 are performed as in example 1, except that the ratio of the number of n- is changed. of tartaric acid per 1 mol of aminopropyl groups. If the ratio is within the proposed limits (examples 1–3), the goal is achieved / When the content of succinic acid is lower than the suggested interval (example 4), the degree of acylation is worse than that of the known. If the content of succinic acid is higher (example 5), the degree of acylation remains at the level of Example 3 (80%). Therefore, the introduction of more than 2.5 mol of succinic acid per 1 mol of aminopropyl groups is not 40

45

50

55

dicarboxylic acid, glutaric acid is taken. Within the limits of the proposed intervals of the parameters of the method (Examples 14-16, 19-20, 2.3-24), the target is broken If the parameters of the method of the proposed interval (Examples 21, 25), then the target does not reach the value of the parameters above suggesting an interval, then the properties of the resulting product are the same as in the case of an upper limit value of the corresponding parameters that are irrational (examples 18, 26), or partial decarboxylation of glutamic acid residues is observed (measure 22).

Examples 27-39 I proceed according to examples 1-13, except for the fact that adilic acid is taken as dicarboxylic acid.

Examples 40-52. I act according to examples 1-13, except

- 17243056

rationally, since the effect does not increase

Examples 6-9, Received by

about 5

0

five

0

Example 1, except that the temperature at which the acylation is carried out is changed. If the temperature is within the proposed interval (Examples 6 and 7), then the goal is reached. At a temperature below the proposed interval (Example 8), the degree of acylation of amino groups is lower than in the known, and if the temperature is higher (Example 9), partial decarboxylation of the grafted succinic acid residues is observed, which is expressed in yellowing of the product

Examples 10-13. Proceed as Example 1, except that the acylation time is changed. If the acylation time is within the proposed interval (examples 10 and 11), the goal is achieved. If the acylation time is less than the proposed interval (example 12), then the product contains a significant amount of adsorbed amber Acids with a degree of acylation lower than that of a known one. An increase in the duration of acylation over the suggested interval (Example 13) does not increase the degree of acylation.

Examples 14-26. In examples 14-26 come in examples 1-13, for

5 except that as

except that as

dicarboxylic acid, glutaric acid is taken. Within the limits of the proposed intervals of the parameters of the method (examples 14-16, 19-20, 2.3-24) the goal is achieved. If the parameters of the method are lower than the proposed interval (examples 17, 21, 25), then the goal is not achieved. the parameter values are higher than the suggested range, the properties of the obtained product are the same as in the cases with the upper limit of the corresponding parameters, which is irrational (examples 18, 26), or partial decarboxylation of grafted glutaric acid (example 22) is observed.

Examples 27-39 Proceed in examples 1-13, except that adilic acid is taken as the dicarboxylic acid.

Examples 40-52. Proceed in examples 1-13, except

reagent. Partial decarboxylation is observed.

1724305

Yu Continuation of the table „2

P

1724305

12

Continuation of table 2

Claims (2)

SUMMARY OF THE INVENTION A method for producing carboxyorganosilica, including the interaction of aminopropyl silica with an acylating reagent when heated, characterized in that, in order to accelerate the process while maintaining the degree of acylation of at least 50%, dicarboxylic acid containing at least two carbon atoms of 50 V is used as the acylating reagent hydrocarbon radical, and on 1 T - _R - _t --- T ’~ 10 2 190 20 75 eleven 2 190 40 85 12 2 190 10 thirty Product contains adsorbed reagent. thirteen 2 190 60 80 14 Glutar 2 190 thirty 90 fifteen 1,5 190 thirty 85 ¹⁶ 2,5 190 thirty 90 17 0.5 190 thirty 40 18 3,5 190 thirty 85 19 2 160 thirty 85 20 2 220 thirty 85 21 2 140 thirty Contains adsorbed reagent 22 2 250 thirty Adsorbed reagent observed 23 2 190 20 . 85 24 2 190 40 90 25 2 190 10 Contains adsorbed reagent 26 2 190 • 60 90 27 Adipic 2 190 thirty 90 28 .1.5 190 thirty 85 29th 2,5 190 thirty 90 thirty 0.5 190 thirty 40 3.1 3,5 190 zo 85 32 2 160 thirty 85 33 2 220 thirty 90 34 2 140 thirty Contains adsorbed reagent 35 2 250 • thirty 90 36 2 190 20 85 37 2 190 40 85 38 2 190. 10 Contains adsorbed reagent 39 2 190 60 90 40 Pimeline 2 190 thirty 75 41 1,5 190 thirty 75 42 2,5 190 thirty__ 80 11 1724305 12 Continuation of the table, 2 1 Amber 2 190 thirty 80 2 1,5 190 thirty 80 3 2,5 190 thirty 80 4 0.5 190 thirty thirty 5 3,5 190 thirty 80 6 2 160 thirty 75 7 2 220 thirty 85 8 2 140 thirty 30 product contains 9 2 250 thirty adsorbed reagent partial decarboxylation of Continuation of the table. 2 1 mol of aminopropyl groups is taken 1.5-2.5 mol of dicarboxylic acid, and heating is carried out in vacuum at 160-220 ° C for 20-40 minutes Table 1 Reagent Qualification G ----------- GOST, TU Silica gel (silicon dioxide) Silochrome C-120 fraction 0.315-0, 5 TU 6-09-17-48- 82 succinic acid Hc GOST 6341-45 Glutaric acid lot H GOST 17153-71 Adipic acid H TU MHP 2618- lot 51 Pimeline H TU 6-09-10- acid 1247-77 Sebacic acid H GOST 15582-70 table 2 Example Dicarboxylic acid Moles per 1 mole of AP-groups --------- t ------- Tempera „round, C Processing time, min ^! The degree of acylation of amino groups,% Note 1 2 3 4 5 6  7 <| 2 3 4 5 6 7 43 0.5 190 thirty 35 44 3,5 190 thirty 80 45 2 160 thirty 75 46 2 220 thirty 75 47 2 140 thirty Contains adsorbi thirty reagent 48 2 250 Decarboxylation observed 49 2 190 20 75 fifty 2 190 40 75 51 2 190 10 Contains adsorbed reagent 52 2 190 60 75 53 Sebacin 2 190 thirty 70 54 1,5 190 thirty 70 55. 2,5 190 thirty 70 56 0.5 190 thirty thirty 57 3,5 190 thirty 70 58 2 160 thirty 70 59 2 220 thirty 75 60 2 .140 thirty Contains adsorbed reagent 61 2 250 thirty 75 62 2 190 20 70 63 2 190 40 75 64 2 190 10 Contains adsorbed reagent 65 2 190 60 75