SU441702A1 - Method for producing ethylene glycol esters - Google Patents

Description

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The invention relates to a process for the preparation of esters, the process for the preparation of esters of ethylene glycol, which are widely used in the chemical industry.

A known method for producing ethylene glycol ester by reacting ethylene with acetic acid in the presence of oxygen and a catalyst selected from the group of hydrohalic acid or organic halides capable of regenerating a free acid, for example methyl, ethyl or protilbromide, under the reaction conditions. The reaction takes place at a temperature of 100-250 ° C and is pressurized. In a single pass, about 1.2-1.7% ethylene glycol diacetate is formed.

The main disadvantage of this method is the low selectivity of the process, which makes the process uneconomical.

The purpose of the present invention is to increase the selectivity of the process.

For this, the process is carried out in the presence of metals of variable valence: tellurium, cerium, antimony, manganese, vanadium, gallium, mouse, cobalt, copper, selenium, chromium or silver.

The reaction is carried out in the same reaction apparatus, but it is possible to carry out the reaction in

two or more vehicles. The reaction can be carried out in a batch and continuous manner, and in the latter case also intermediate products, such as dihaloethane or ethylene monohaloxycarboxylate, can be returned to the process, which will increase the yield of ethylene glycol diacetate.

Carboxylic acids can be used both as a solvent and as an acidic compound, which is the desired ester. However, instead of a carboxylic acid, an inert solvent, such as benzene, can be used.

In the described method, the following are used: acetic acid picolinic, nicotinic, 3-indoli.Tuxusna, furancarbonova. 2-thiophencarbone, hp) schlinow.

It is preferable to use a carboxylic acid, which is an aliphatic or aromatic acid, but preferably monophenyl 3

aliphatic and lower aliphatic acids, for example, lower unsubstituted monoaliphagic or benzoic acids.

The method involves the use of a mixture of carboxylic acids in any desired ratio, but preferably uses the same acid as the solvent and as the acidic compound, the ester. The method also provides for the possibility of using the final ether product as a solvent. The carboxylic acids used may be in the form of any of the available acids, for example aqueous solutions. However, it is preferable to use commercial acids containing not more than 25% of water, in particular less than 5% of water, for example, 98% acetic acid. The content of ordinary organic and inorganic impurities, usually present, of them in various commodity acids is allowed. During the drying process of the proposed method, these impurities may remain or be removed.

The monovalent metal compound (metal cation) is a simple salt or mixture. For example, you can use any carboxylic acid group of these carboxylic acids as the anionic part of this salt, and Te, Ce, Sb, Mn, V, Ga, As, Co, Cu, Se, Cr or Ag, or a mixture of metal cations as the cationic part of Te, Ce, Sb, Mn, V, Ga, As. . The valence state of the metal during the initial reaction can be any. For example, you can first use a divalent or trivalent manganese cation, monovalent or divalent copper cathodes, divalent or trivalent cobalt cations, etc. For this method, the only decisive requirement for metals is their variable valence at any initial valence state. A variable-valence metal cation can be added in any form that, in solution, under the reaction conditions, will yield at least some soluble metal ions. The metal compound added can be, for example, the metal itself in a finely divided form, metal carbonate, oxide, hydroxide, bromide, chloride, lower alkoxide (methoxide), metal phenoxide or carboxylate, in which the carboxylate ion is the same as the anion of the solvent or not. such. If the process requires the use of a variable metal valence cation and a bromide or chloride, then any of these metals can be used as its bromide or chloride. In a preferred embodiment, the metal compound is in the form of an oxide, hydroxide or salt of an acidic solvent. In the most expedient embodiments, the salt is a carboxylic acid salt of a metallic compound, which preferably contains an anion of an aromatic acid or an aliphatic acid, for example acetic, propionic, and butyric, or benzoic acid, but better than acetic acid, in the case of

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Those metals are preferably used in the form of the metal itself or its oxide. The most preferable cations of metals with irreducible valence, subdivided according to their use in combination with a source of bromide or chloride, are Te, Ce, Sb, Mn, V, Ga, As, Co, Cu, Se or Ag with a source of bromide, in particular Te , Ce, Sb, Mn or V, especially Te, Ce, Sb or Mn, for example, Te and

bromine or hydrogen bromide; and Ce, Mn, Co, Cu, Se or Cr, with a source of chloride, in particular Ce, Mn, Co, Si or Se, especially Ce, Mn or Co. The metal compound may contain impurities normally present in commodity metal compounds and may not require further purification.

If at the initial stage of the reaction, instead of bromine or chlorine is used, their compounds are used, then any compound capable of forming bromine or chlorine ions in solution can be taken up by oxidation or other chromium. For example, you can use hydrohalic acids (gaseous or boiling, especially concentrated aqueous acid), any metal halide, such as bromides or chlorides of alkali, alkaline earth or heavy metals (potassium bromide, calcium chloride, manganese bromide and H.), or bromides metal chlorides, or organic halides, for example, a three-halide compound of an alkali metal, lower aliphatic halides (propyl halide, pentyl halide), cyclic

lower aliphatic halides (graloid cyclohexyl) or lower aliphatic dihalogen compounds (ethylene chloride, ethylene bromide); All of these substances are considered compounds capable of forming bromide or chloride anions.

Preferably the reaction is carried out in the presence of bromine or chlorine or halogen acid, alkali metal or alkaline earth metal halides, or mixtures of chlorides and

bromides, and especially in the presence of concentrated hydrobromic acid, concentrated hydrochloric acid or potassium bromide. The halogen used may contain impurities common to commercially available

halogen industry.

Different reagents can be used in a wide range of concentrations, the effective minimum concentration depends on r temperature, time and type of used.

halogen and metal. Typically, the concentration of halogen, expressed as a weight percentage of bromine or chlorine relative to the total solution, may be 0.01-30% or more, preferably 0.1-20%, especially 0.5-10%. The concentration of all the cations present, expressed as the ratio of cation equivalents to halogen equivalents, in the form of bromine or chlorine, can range from 1: 0.1 to 1: 100, but preferably 1: 0.2 to 1: 40 and

especially 1: 1 to 1: 20.

The molar ratio of oxygen to ethylene does not play a decisive role, and therefore any suitable ratio can be applied.

If the carboxylic acid is used as a solvent, as a slot-gut component, it is used in excess compared to the theoretical amount needed: for the reaction. When using an inert solvent, the amount of carboxylic acid should, for practical reasons, be at least equivalent to the amount needed to obtain the final product from ethylene.

The reaction temperature may range from 80 ° C to the boiling point of the solvent in the reaction zone, preferably the temperature is in the range of 100-200 ° C, especially 120-180 ° C.

The duration of the reaction to a large extent depends on the concentration of the reagents and may therefore be from 1 minute to 1 day or more.

Example 1. To the enamelled reactor containing 10 g of acetic acid, an appropriate amount of metal and halogen is added, as indicated below. Then, a new pressure is created in the reactor by supplying oxygen under a pressure of 7.03 kg / cm abs. and ethylene at a pressure of 14.06 kg / cm abs. At that, the reaction mixture is heated, stirring, for 2 hours at 160 ° C. Ethylene glycol diacetate is obtained in the following yields.

The table shows the results of examples from 1 to 44, they demonstrate the uniqueness of combinations of metals and halogen in this invention. When using chloride alone without any variable valence metal according to the invention (Examples 3 and 4), ethylene glycol acetate is not encased. When using bromide alone, for example, KBr (example L or bpoma (2), a low yield of ethylene glycol diacetate is observed. Similarly, using any of the metals of the invention without a halogen source (examples 34-44) does not produce ethylene glycol diacetate. When using metals but the invention with a source of chloride or bromide (primers 5-33), significant yields of ethylene glycol diacetate are obtained.

It is clear that the combination of metal and halogen source provides unexpectedly high yields compared to those cases where only halogen or metal is used. This combination allows to GET yields far exceeding the simple effect of combining halogen with metal :. and get in many cases exits that are 5-10 times higher than the outputs that could be

would expect from the simple effect of attachment.

In the course of his studies, he was a man of the day, and he was a man of the day. 2-naphthalenuacetic, cyclohexanecarboxylic, pitcholinic, nicotinic, 3-indolplusacetic. furacarboxylic, 2-thiophencarboxylic, or quinolinoic instead of acetic acid, the corresponding ethylene glycol-carboxylate compound is obtained. When conducting experiments in examples 8, 22 or 24 with equivalent amounts of cobalt bromide, hydroxyhydroxycritic. copper carbonate, cerium metalate, copper phenol, instead of a metal compound, have similar results.

When using in experiments 5 or 14 equivalent amounts of chlorine, lead bromide, potassium tribromide, 1-chloropropane, vaclohexyl bromide or dibromoethane instead of the specified source of halogen, similar results are obtained.

When conducting experiments 5. 8, 12. 16 or 29 at temperatures of 80, 120. 140. 180. 200 ° C for 24, 16, 8, 1 or 1/2 hours, respectively, get similar results.

When using manganese bromide, cobalt bpomide or antimony chloride instead of manganese acetate and lithium chloride in an Nymer 13, they get similar results.

When conducted, 1i of experiment 23 using 0.123, 0.74, or 1.85 g KBr instead of 0.37 g KBG, similar results are obtained.

Apply at the pressure of 7.03, 28.12 and 42.19 kg / cm abs. ethylene instead of pressure 14.06 kg / cm abs. ethylene in experiment 5 receive similar T results.

PRI me R 45. An example illustrates the variety of halogen sources applicable in this invention. 0.2 g of TeO was added to a glass-enamelling reactor, with 10 g of acetic acid. and 0.6 g. MpVg ..:. The reactor was pressurized by supplying oxygen under a pressure of 7.03 kg / cm abs. and ethylene under pressure of 14.06 kg / cm abs. After that, the reaction mixture is heated, moving, for 2 hours at 100 ° C. The output of ethnle} 1glnkol 46.8%.

When using equivalent amounts of tellurium, cerium, antimony, vanadium, gallium, arsenic, cobalt, copper, selenium, and silver bromides instead of manganese bromide, similar results were obtained. 9 The subject matter of the invention 1. A method for producing ethylene glycol esters by reacting ethylene with molecular oxygen and carbon: at a high temperature and pressure in the presence of a compound capable of forming bromide or chloride anions, and isolating the target product by known technological methods, characterized in that in order to increase the selectivity of the process, the reaction is carried out in the presence of metals of variable density — tellurium, cerium, antimony, manganese, vanadium, gallium, arsenic, cobalt, copper sulfur lena, chromium n silver, 2. The method according to claim 1, characterized in that the process is carried out at 80-200 ° C.