CS243371B1 - Method of 2,4,6-trimethylpyridine and 2,3,6-trimethylpyridine mixture winning - Google Patents

Abstract

?í!4eo’*..’í<,*F*v*ní «■»·! 2,4,6-trisethyl- diíÍuzn5s.íi,2,3,6”tri*,thírlWridiaw « kolS- «wMAeovýeb sáaad čarnouhalná- Bóó«5ÍlM°ull*Índ“0» ropné&o o synthetic štavnlová. J.hopodmriáin^ ētavelsny 2,4,6-trlaethyl- a^rnck^r8 2,3,6-triecthylpyridnu se lískaji ?*?!!?££?* «Bési crystallization aa posílneho rnakfnť11 “•poísrního rospusztodta chalsenia “íei· KrytelicMý part oddelě? 2^6^1 · ro2lotí· ZÍ»NA ee saěs Pyridineů

Description

The invention relates to a process for the preparation of a mixture of 2,4,6-trimethylpyridine 2,3,6-triasthylpyridine and a collidine fraction of pyridine mixtures of black, brown coal, petroleum or synthetic origin.

The collidine fraction is a mixture of pyridine aaads boiled at a temperature of 168-175 ° C, in which isoaeml 2,4,6- and 2,3,6-trlaethylpyridines predominate. The average colloidal fraction of the black-black origin was 45% 2,4,6-triaethylpyridine, 17,3,3,6-triaethylpyridine, 10% 3,5-diaethylpyridine, 6 * 3,4-diaethylpyridine, 7 9 aniline, 10 9 isoaernlch. and 5-lower-boiling pyridine homologues.

The recovery of the components and collidine fraction is usually carried out by chemical aeparation processes, which in principle are either the addition of crystalline salts, adducts, co-lesions and clathrates and inorganic or organic compounds, or different reactivity of the collidine fraction components with amides, aldehydes and other substances.

Most commonly, the components of the collidine fraction are combined with hydrochloric acid or hydrogen chloride gas, where 2,4,6-triaethylpyridine hydrochloride crystallizes in water or other media.

This is decomposed and pure 2,4,6-trimethylpyridine is described (Chem. Průa. 23, 124, 1973).

In the remaining aad after the isolation of 2,4,6-triaethylpyridine, the hydrochloric acid again mixed the 2,4,6-triaethylpyridine and 2,3,6-triaethylpyridine hydro-chlorides (patent CSSS 147 295).

Further, copper chloride chloride has been added to the 2,4,6-triaethylpyridine salt. Crystals of the copper chloride-2,4,6-triaethylpyridine complex precipitate from the reaction mixture, which are separated, washed and washed (Chem. Průa. 23, 620 (1973)).

According to other literature data, 2,3,6-trimethylpyridine can also be printed with copper chlorides, similarly by 2,4,6-triaethylpyridine and 2,3,6-triaethylpyridine (MSB patent) 1,245,963; Cham. Pra, J, 202, 1965).

The disadvantages of these processes are the strong corrosive effect of hydrochloric acid or gaseous hydrogen chloride on the production equipment, the economic demands of the auxiliaries and the formation of harmful waste substances (waste water) containing salts and copper in the case of copper chloride processes which need to be I pose a very serious threat to the environment. In the phenol process, it is necessary to use a sophisticated cooling agent.

Some of the above drawbacks are solved by the process of the invention of the 2,4,6-triaethylpyridine and 2,3,6-triaethylpyridine mixture. It is based on the use of tartaric acid for the crystalline formation of 2,4,6-triaethylpyridine and 2,3,6-triaethylpyridine.

In the actual method, to the collidine fraction ss, oxalic acid is added in an aoleic acid: 2,3,6-triaethylpyridine ratio of 0.5-1: 1 and the organic solvent used to aseotropically dewater the mixture.

OF

After this dewatering, the mixture was cooled, whereupon crystals of 2,4,6-triaethylpyridine and 2,3,6-trimethylpyridine formed were formed. Upon reaching 20 ° C, the crystals are separated, washed with a non-polar solvent and decomposed.

A mixture of 2,4,6-triaethylpyridine and 2,3,6-trimethylpyridine is obtained. Aromatic hydrocarbons are preferably used as the organic solvent used for dewatering, and the reaction mixture can be cooled with a controlled temperature drop over time.

It is more preferred to dilute the crystallizing mixture with aromatic hydrocarbons or other nonpolar surfactants after reaching 80 ° C. The decomposition of 2,4,6-triaethylpyridine azalate and 2,3,6-triaetbylpyridine is preferably carried out with an aqueous solution of an alkali metal hydroxide or thermal heating.

The main advantages of this process lie in obtaining the other major components of the collidine fraction in a high yield corresponding to the Siatote. The yield of 2,4,6-trinetbylpyridine-2,3,6-triaethylpyridine is obtained in a single step in a yield of over 70 ° C and a purity of over 95%.

Further, in this process, they eliminate all or part of the disadvantages of previously utilized poetups, thus achieving depor- tions of investment equipment and operating costs. The process is more environmentally friendly!

Specific embodiments of the salts of 2,4,6-triaethylpyridine and 2,3,6-triethylpyridine of the invention are described in the following examples.

He did

To 100 collidine fractions having a boiling range of 168 to 175 ° C, containing 47.2%

2,4,6-triaethylpyridine from 25,6 * 2,3,6-triaethylpyridine is added 61 g of oleic acid and 25 g of benzene and isothermally distilled off with benzene.

Thereafter, the reaction mixture is cooled at a controlled temperature drop of the reaction mixture to 8 ° C / h. At 80 ° C, 263 g of benzene are added to the reaction mixture and cooling is continued and the temperature drop is continued until the temperature reaches 20 ° C.

The crystalline fraction was separated and passed through 263 g of benzene. 206 g of acetonitrile 2,4,6-triaethylpyridine and 2,3,6-triaethylpyridine are obtained, which decompose 200 g of a 50% aqueous solution of sodium hydroxide.

The released eaes of trlaethylpyridines ee are extracted into benzene, drained by eaeotropic distillation, benzene ee distills off e as the last fraction of the ee of distillation 51 grams

2,4,6-triaethylpyridine and 2,3,6-triaethylpyridine in purity.

Example 2

To 100 g of the colase fraction purified in Example 1 ' is added 49.2 g of acetic acid and 21 g of toluene and the mixture is echotropically dewatered. The reaction mixture was then cooled to 20 ° C. The crystalline fraction was separated and passed through 250 g of bensene.

177 g of 2,4,6-triaethylpyridine-2,3,6-trlaethylpyridine are obtained which are decomposed at 190 ° C. The decomposition products obtained are aseotropically dehydrated, aromatic hydrocarbons and distilled off, and then distilled out 36.3 g of 2,4,6-triawthylpyridine, and

2.3.6- triaethylpyridine in a purity of 99.2%.

Example 3

To 100 g of the collidine fraction specified in Example 1 were added 61 g of Elavelic acid and 27 g of toluene-xylene fraction and were echotropically drained. Thereafter, the reaction mixture is cooled with a controlled decrease in the reaction temperature of 7 ° C / h to 20 ° C.

200 g of toluene-xylene fraction were added to the reaction mixture at 85 ° C. The crystalline fraction was separated and treated with 270 g of benzene.

212 g of 2,4,6-trlaethylethylpyridine and 2,3,6-triaethylpyridine are obtained which are decomposed with 200 g of 50% aqueous sodium hydroxide solution. The liberated salt of triethylphenylpyridines is extracted into benzene, drained by aseotropic distillation, the bansene is distilled off, and then 51.8 g of 2,4,6-triaethylpyridine and 2,3,6-triaethylpyridine lard are distilled at a purity of 96.6%.

Example

To 100 g of the collidine fraction specified in Example 1 aa, add 60 g of oxalic acid and 23 g of toluene and drainage aaotropically. The reaction mixture is then cooled at a controlled temperature of the reaction mixture of 5 ° C / h to 25 ° C.

While cooling, 235 g of toluene are added to the reaction at 80 ° C. The crystalline fraction aa separated and produced 270 g of bensene. It attracts 205 g of 2,4,6-triaethylpyridine and 2,3,6-triaethylpyridine oxalate, which is allowed to warm to 190 ° C.

The aromatic hydrocarbons are distilled off and then 48 g of a mixture of 2,4,6-triaethylpyridine and 2,3,6-trlaethylpyridine in a purity of 96.1 are distilled off.

Claims (6)

I. Method of sanding the sausage 2,4,6-triaethylpyridine and 2,3,6-triaethylpyridine with a colliin fraction of pyridine and coal, brown coal, petroleum or synthetic origins, characterized in that to the colloline fraction of these constituents is added oxalic acid in an aolar ratio of oxalic acid - content of 2,4,6-triaethylpyridine * 2,3,6-trlaethylpyridine in collidine fraction 0,5: 1 to 1: 1, the reaction mixture is drained by aseotropic distillation with organic phosphate surfactant, the dewatered reaction mixture is cooled, cooling occurs during cooling Crystallisation of the resulting 2,4,6-triaethylpyridine and 2,3,6-triaethylpyridine oxalate, which is removed, passed through a non-polar solvent and decomposed to a pure mixture of 2,4,6-triaethylpyridine and 2,3,6-triaethylpyridine. i. The process of claim 1, wherein aromatic hydrocarbons are used for aseotropic dewatering of the reaction and the organic solvent. 3. Process according to Claims 1 and 2, characterized in that the crystallization of the reaction mixture is carried out under a controlled temperature drop of the reaction mixture, preferably at a rate of 5 to 10 ° C / h. 4. A process according to any one of claims 1 to 3, characterized in that, after the dewatered crystalline reaction mixture aa, after reaching a temperature of 90 to 60 ° C, preferably 80 ° C, it adds a nonpolar phosphate surfactant, preferably aroaatic hydrocarbons. fraction 1: 1 to 5: 1. 5. A process according to any one of claims 1 to 4, wherein the decomposition of the oxalates of 2,4,6-triaethylpyridine and 2,3,6-trinethylpyridine is carried out with an aqueous solution of an alkali metal, preferably 50% of rostokoe sodium hydroxide. 6. The process of claim 1, wherein the decomposition of the oxalate of 2,4,6-triaethylpyridine and 2,3,6-triaathylpyridine is carried out by tapping and heating to 160-200 ° C.