RU1768580C - Method of isobornylacetate synthesis - Google Patents

Abstract

Usage: odorant chemicals, intermediate in the production of camphor. SUMMARY OF THE INVENTION: technical camphene containing 15-20% tricycylene is acetoxylated with acetic acid, mol. ratio (camphene and tricyclic): acid 1: (1-2), 10-70 ° C, feed rate 0.6-0.35. Catalyst: cation exchange resin in the H + form, containing 43 wt.% Polypropylene fiber and 57 wt.% Grafted copolymer of styrene with divinylbenzene. Selectivity in the amount of camphene and tricycle is 86-88%. 2 tab.

Description

The invention relates to chemical technology, and in particular to a method for producing isobornyl acetate, used as an aromatic substance, as well as an intermediate in the synthesis of camphor or as an enhancer of the activity of pyrethrin aerosols against flies or as a gametocide for cereals and sunflowers.

Known methods for producing esters from alcohols and carboxylic acids, for example, from borneol and monochloroacetic acid in the presence of concentrated sulfuric acid 1. However, this method of producing esters requires the use of expensive alcohols as raw materials, and the use of sulfuric acid as a catalyst leads to the formation of large amounts of wastewater.

Known methods for producing complex zethers from olefins and carboxylic acids, for example, isobornyl acetate from industrial camphene containing 75% camphene and 20% tricycylene, with acetic acid in the presence of concentrated sulfuric acid as a catalyst, taken from the calculation of 5.0% by weight of camphene , at 25-60 ° С. The reaction time is 4 hours. The yield of isobornyl acetate 68.1% based on the reacted camphene 2.

The disadvantages of this method of producing isobornyl acetate are 1

the use of sulfuric acid as a catalyst, which leads to the formation of a large amount of wastewater containing sulfuric acid, acetic acid, as well as organic impurities;

low yield of the target product

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A known method for producing isobornyl acetate by reacting camphene with two equivalents of acetic acid in the presence of activated clay as catalyst (15% by weight of camphene) at 85-95 ° C is used as a catalyst. The reaction time is 7 hours. The yield of isobornyl acetate 80-85% based on the reacted camphene 3.

The disadvantages of this method of obtaining

  “- -CH1CH & - -, -“ P. . - lie

isobornyl acetate are:

difficulty (this is the fraction of the reaction product from catalysis Utor;

the formation of a significant amount of side products (alcohols 0-4%, boric acetate 2-5%, isocamphyl acetate 2-5%);

low yield of the target product (80-85%);

high reaction temperature (85-95 ° C);

long process time (7 hours).

There is a known method for producing isobornyl acetate by reacting camphene with two equivalents of acetic acid in the presence of a sulfonated granular macroporous styrene-divinylbenzene copolymer, KU-23 cation exchanger, as a catalyst (15% by weight of camphene). The reaction time is 5 hours. The yield of isobornyl acetate 70-75% based on the reacted camphene.

The disadvantages of this method of producing isobornyl acetate are:

the formation of a significant amount of by-products (alcohols 0-4%, boric acetate 4-8%, isocamphyl acetate 5-20%, unidentified compounds 0.5-1.0%);

low yield of the target product (70-75%);

high reaction temperature (85-95 ° C);

low mechanical strength of the catalyst;

the ability of the catalyst to cure upon contact with the reaction mixture.

Of the known methods for the preparation of isobornyl acetate, the closest to the claimed method is the method for producing isobornyl acetate by reacting camphene with two equivalents of acetic acid in the presence of a sulfonated styrene copolymer with 8% divinylbenzene sulfonic acid KU 2-8 as a catalyst at 85-95 ° C. The reaction time is 5 hours. The yield of isobornyl acetate 75-80% based on the reacted camphene.

The disadvantages of this method of producing isobornyl acetate are:

low yield of the target product (75-80%);

the formation of a significant amount of by-products (alcohols 0-4%, boronyl acetate 2-4%, isocamphyl acetate 2-7%); high reaction temperature (85-95 ° C).

The aim of the invention is to increase the yield of the final product, increase productivity and simplify the process.

This goal is achieved by the production of isobornyl acetate by reacting camphene technical with acetic acid in the presence as a catalyst of fibrous sulfocationionite, which is sulfonated

polypropylene fiber with a radiation-grafted copolymer of styrene and divinylbenzene.

The preparation, properties and possible applications of a sulfonated polypropylene fiber with a radiation grafted copolymer of styrene and divinylbenzene (the extraction of non-ferrous metals and sorption of urea from dilute aqueous solutions are described in 4J.

To carry out the method, a solution of technical camphene in acetic acid is passed at a temperature of 10-70 ° C through a thermostatically controlled flow-type tube-filled reactor, which is a fibrous cation exchange resin - a sulfonated polypropylene fiber with a radiation-grafted copolymer of styrene and divinyl benzene.

The chemical nature of what is happening

the process can be represented by the following diagram;

40

Ason

Tricycle

Kai FENISoVornyl acetate catalyst

The desired product, isobornyl acetate, is formed by the addition of acetic acid in the presence of a catalyst to both camphene and tricyclene.

0 The proposed method, in contrast to the known one, involves the use of a sulfonated polypropylene fiber (43 wt.%) With a radiation grafted copolymer as a catalyst (57

5 wt.%) Styrene and divinylbenzene. This catalyst provides a higher yield of the target product, reduces the duration of the process and makes it possible to carry out the process at lower temperatures,

The following examples are provided to better understand the present invention.

Example 1. A solution of technical camphene containing 83.5% smfphen and 15.5% tricyclene in acetic acid with a ratio of 1 mol (camphene + tricyclene) / 1 mol of acetic acid is passed at 70 ° C through a thermostatic glass tube filled with a catalyst, which is an air-dry sulfonated polypropylene fiber with a radiation grafted copolymer of (0.57) styrene and 2% divinylbenzene (H-form, total exchange capacity 3.76 mEq / g), at such a rate so that the duration of contact of the reactants with the catalyst composition la 1.5 hours. The catalyst was neutralized with an aqueous solution of sodium carbonate, then it was washed with water and analyzed by gas-liquid chromatography. Composition, wt.%: Tricyclene 3,5; camphene 21.0; isophenhyl acetate 2.5; isobornyl acetate 65.5; isocamphyl acetate 2.0; and unidentified compounds 5.5. The yield of isobornyl acetate 86.8% based on the reacted camphene and tricycle.

PRI me R s 2-13. The process is carried out analogously to example 1 at various temperatures, the duration of the reaction, as well as the molar ratios of acetic acid: (camphene + tricycylene).

Example 14 (comparative under the conditions of the prototype). A mixture of 12.9 g (0.1 mol) of technical camphene containing 78.0% camphene and 19.9% tricyclene (the rest is fenheny), 12.1 g (0.2 mol) of acetic acid, grade hc, and 2.04 g sulfonic cation exchanger KU-2-8 (GOST 20298-74) (air-dry, 15% by weight of technical camphene) is stirred for 5 hours at 85-95 ° C. The processing of the catalysis is carried out similarly to that described in example 1. According to the results of GLC analysis of the obtained mixture of the composition, wt.%: Tricycle 12.1; camphene 34.1; isophenyl acetate 0.2; isobornyl acetate 45.5; isocamphyl acetate 1.8; and identified compounds 1.6. The yield of isobornyl acetate 83.9% based on the reacted camphene with tricycylene.

Example 15 (comparative). A mixture of 12.9 g (0.1 mol) of technical camphene containing 78.0% camphene and 19.9% tricyclene, 12.1 g (0.2 mol) of acetic acid, grade XC, and 2.04 g of KU- sulfocationite. 2-8 (GOST 20298-74, 15% by weight of technical camphene) are stirred for 5 hours at 20 ° C. The processing of catalysis is carried out similarly to that described in example 1. As a result of GLC analysis of the resulting mixture

its composition is found, wt.%: tricycylene 21.9; camphene 68.8; isobornyl acetate 4.5 and unidentified compounds 4.8. This composition corresponds to a 9.5% conversion of 5 a mixture of camphene with tricycylene.

The results are shown in table 1.

As can be seen from examples 1-13, the use of a sulfonated polypropylene fiber as a catalyst with 0 radiation-grafted copolymer of styrene and divinylbenzene allows to increase the yield of isobornyl acetate based on reacted camphene with tricycylene from 75-80% (according to the known method, pro-5 totipu) up to 86.8-96.1 (as proposed).

The advantages of the proposed method in comparison with the known are as follows.

In the known method, the yield of the target 0 product does not exceed 80% based on the reacted camphene. In the proposed method, the reaction between acetic acid and technical camphene in the presence of a sulfonated propylene fiber with a radiation grafted copolymer of styrene and divinylbenzene as a catalyst proceeds in high yields (86.8-96.1% based on the reacted camphene with tricycylene). Therefore, the 0 proposed method is more economical in terms of consumption of raw materials (see Table 2).

In the known method, the reaction proceeds at 85-95 ° C, and in the proposed method, 5 at 10-70 ° C (preferably at 10-30 ° C), which reduces energy consumption per unit of production.

In the proposed method, sulfonated 0 polypropylene fiber with a radiation grafted copolymer of styrene and divinylbenzene is used as a catalyst. When it was in contact with the reaction mixture for 3 months, no changes were noticed either in the appearance or in the catalytic activity of the catalyst. For this reason, the proposed process for the preparation of isobornyl acetate is more reliable.

Thus, the use of fibrous sulfocationite allows you to:

to increase the productivity of the process by reducing the reaction time from 5 (according to the prototype) to 1.5-3.5 hours (examples 7-10), as well as increasing the conversion of the initial carbon-5 hydrogens from 55.0 (prototype, example 14) to 97% (example 10);

simplify the process technology since

no equipment needed for

preheating of the initial reatents (prototype reaction temperature

85-95 ° C) and maintaining the temperature of the reaction mixture during the reaction at 85-95 ° C. When carrying out the process at 20 ° C using cation exchanger KU-2-8 (example 15), the conversion of the mixture of camphene with tricycylene does not exceed 10% (example 15);

to increase the selectivity of the reaction of acetic acid with a mixture of camphene with tricycylene from 83.9% (prototype, example 14) to 94.8-96.1% (examples 7-13).

As can be seen from table 2, for the production of 1 ton of isobornyl acetate, the proposed method requires a raw material cost of 303.73 rubles. less than the prototype.

Claims (1)

SUMMARY OF THE INVENTION Method for the preparation of isobornyl iethate by acetoxylation of camphene acetic acid using a cation exchange resin in the H + form as a catalyst, containing a sulfonated styrene copolymer with 2 wt.% divinylbenzene based on the polymer mass, at an elevated temperature. characterized in that, in order to increase the yield of the final product, increase productivity and control - Grove process, acetoxylate camphene containing 15-20% tricycylene, and a sulfonated polymer containing 43 wt.% polypropylene fiber and 57 wt.% grafted styrene copolymer with divinylbenzene, the process is carried out at a molar ratio (camphene + tricyclene): acetic acid, equal to 1: (1-2), temperature 10-70 ° С, the duration of contact of the feed with the catalyst is 1.5-3 hours. Interaction of acetic acid with industrial coke in the presence of catalysts for sulfonated polypropylene fiber md) with a radiation-grafted copolymer (57 wt%) styrene and divinylbenzene; KU-2-8 Sulphonated polypropylene aolco with radiation-grafted copolymer of styrene and DVB ($ 2) The process is carried out under the conditions of the prototype on a mixture of camphene and tricycle. Table 1 table 2 Comparative costs of raw materials spent on the production of 1 ton of isobornyl acetate obtained by the prototype method and the proposed method