RU1836317C - Method for obtaining sodium or potassium salts of ortho carboxylic acids - Google Patents

Abstract

Usage: as intermediate reagents, as well as in printing. The product is sodium or potassium salts of orthocarboxylic acids f-ly R-C (OM) (OM) 2, where R is aryl, furyl, R-CH-CH-, СНз () 2-, (СНе) -. M Na, K. Yield 78-94%, basic substance content 94-98%. Reagent 1: carboiopa acid f-ly R-COOH, where R is indicated. Reagent 2: NaOH or KOH in the form of granules. Reaction conditions: in an inert solvent, for example diethyl ether or benzene, or homologues thereof, at 35-70 ° C. with vigorous stirring of the alkali granules with a mechanical stirrer, with a molar ratio of alkali jarbonic acid; acid 4-5: 1 and a ratio of the volume of solvent to the mass of the reaction mixture 10-12: 1. 2 tab.

Description

The invention relates to organic chemistry, and in particular to an improved method for producing sodium or potassium salts of orthocarboxylic acids or alcohol - gem-triols of formula 1

OM

R-C-OM OH

(D

where R-ary, furyl, R-CH-CH-. CHz - () g-,. M - Na, K,

I ..

SNZ

used as intermediate reagents, as well as those used in printing.

Known methods for producing salts of orthocarboxylic acids by mixing organic acids in a two-phase liquid system, dioxane-concentrated alkali (1), as well as the gradual addition of concentrated alkali to a heterogeneous organic acid-water mixture to form an abundant precipitate of the product (2). The second method is the closest analogue of the claimed. Product formation occurs by the reaction equation

MY IMO H

 -; TS R-C - OM Onomoi (2)

A disadvantage of the known method is the need to purify the product from alkali residues. The use of DAL. Of this purpose of water or alcohol leads to r. product, and other solvents and and up alkalis and do not separate it from the product.

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The aim of the invention is to simplify the technology, increase the yield and purity of the product.

The reaction mass is formed on the basis of a solvent inert to alkali and to the orthocarboxylic salt (for example, diethyl ether, benzene or its homologues), in the medium of which carboxylic acids interact with granular alkali (NaOH or KOH). During the reaction (with vigorous stirring of the heterogeneous mixture), the potassium or sodium salt of orthocarboxylic acid (1) is formed correspondingly to the above reaction. Salt (1) in suspension is accumulated in the solvent medium, while unreacted alkali in the form of granules after stopping stirring is collected at the bottom of the flask. Self-heating of the mixture ensures the normal course of the process. In the environment of diethyl ether, boiling of the solvent creates automatic temperature control at 35 ° C. In other environments, the temperature rise exceeds 60-70 ° C. After 1 hour after the self-heating of the mixture is complete, the stirrer is stopped and the mixture is separated by specific gravity, as a result of which the alkali is collected at the bottom, and the product is decanted together with the solvent. Separation from the solvent is carried out in one of the known ways: by centrifugation or squeezing on a glass porous filter, after which the product is dried in a thermostat at a temperature exceeding the solvent bp by 10-15 ° С.

In this way, potassium or sodium salts of orthocarboxylic acids of the indicated structure are obtained with a basic substance content of 94-98% at a yield of up to 94%. The product is stable when stored in air.

PRI me R 1. Disodium orthobenzoate. 10 g of granular NaOH was placed in a 0.5 L round bottom flask. equipped with a quick mechanical stirrer, passed through a reflux condenser, immediately pour 200 ml of diethyl ether, add 6.1 g of crystalline benzoic acid and stir for 2 hours. A stable suspension of the product is formed. During stirring, the temperature rises spontaneously, which is accompanied by a slight boiling of ether. After the ether is boiled, the mixture is stirred for another 1 hour, after which the mixer is turned off and the mixture is left to stand for 0.5 hours. The heterogeneous mass of the product-ether is poured from granules of unreacted alkali onto a glass filter. The remaining alkali is mixed

with 100 ml of a new portion of diethyl ether which is attached to the product on a glass filter. When evacuating with a water-jet pump, the product is squeezed out of ether and dried in a thermostat at a temperature of 40-50 ° C for 2 hours. 7.7 g (94%) of a white crystalline product is obtained which is stable (non-wet) when stored in air.

Found,%: C 45.0; H 3.5: Na 25.2.

Calculated by the formula StNeOzMea,%: C 45.6; H 3.26; Na 25.

By potentiometric titration of a sample of a product dissolved in water, 94% (dissolved 0.3b17 g, determined by titration 0.356 g) of the main substance of the product is obtained,

Example 2. Disodium orthofuryl acrylate. In a 500 ml round bottom flask with a stirrer through reflux, 200 ml of benzene are stirred for 2 hours with 8.6 g (0.215 mol) of granular NaOH and 6.9 (0.05 mol) furanacrylic acid (crystals partially dissolved in benzene). The reaction is carried out as described in Example 1. 8.8 g (88%) of a white crystalline product are obtained which are stable when stored in air.

Found,%: C 42.2; H 3.3; Na 20.2.

Calculated by the formula C Hb04 No. 2,%: C 42.0; -H 3.0; Na 23.0. :

Potentiometric titration established the main substance in a weighed 96%. On the PC spectrum of the petroleum jelly product there is a VOH 3800 band.

Based on KOH granules, as well as other solvents indicated in Table 1, the process for all of the listed products is carried out in the same manner as in Examples 1-2.

In all cases, alkali is taken in excess against stoichiometry to bias the process and complete the reaction. This is achieved with an acid-base ratio of 1: 4 or 1: 5. The volume of solvent should be 10-12: 1 to the mass of the reaction mixture. A smaller amount of solvent will make the mass viscous, not amenable to stirring, and a larger one will make it impractical to consume a large amount of solvent.

The quality control of the product and its identification are carried out by several analytical methods: flame-photometric determination of the percentage of K or Na. elemental analysis, IR spectroscopy, Potentiometric titration.

Table 1 gives data on the progress of the reaction and the yield of the product.

Physico-chemical characteristics of the target products are given in table.2.

Claims (1)

SUMMARY OF THE INVENTION A method for producing the sodium or potassium salts of orthocarboxylic acids of the general formula  oh yeah he where R is aryl, furyl,, CH3 () 2-, CH2 C-CH3, M is Na or K. I reacting a carboxylic acid of the general formula RCOOH, where R is as defined, with NaOH or KOH followed by purification of the product, characterized in that, in order to simplify the technology, increase the yield and purity the target product, the process is conducted in the presence of granules of solid alkali in a solvent inert to alkali and to the reaction product, for example diethyl ether, benzene or its homologs, the temperature of heating the reaction mixture 35-70 ° C, with vigorous stirring of the alkali granules with a mechanical stirrer, and the alkali taken in relation to carboxylic acid in molar the ratio of 4-5: 1, and the volume of the solvent 10-12: 1 to the mass of the reaction mixture. Table 1  Organic carboxylic acid is taken in an amount of 0.05 mol. KOH or NaOH is taken in an amount of 0.20-0.25 mol. The solvent is taken in an amount of 180-220 ml. 4-4 Melting point of an organic acid with the same R obtained by hydrolysis of orthocarboxylic salts. Salts themselves do not melt at temperatures up to 700-800 ° C.  Like m. of dipotassium or disodium salt of orthocarboxylic acid, determined by potentiometric titration. The estimated value is given in parentheses. Table