SU641872A3 - Method of obtaining butendioldiacetates - Google Patents

Description

I

The invention relates to chemical technology, in particular to a method for producing butandiol diacetate, in particular 1,4-diacetoxybutene-2 and 3,4-diacetoxybutene.

Butandiol diethers are valuable intermediates, for example, for the preparation of butandiol and butanediol. Budendiol-3, 4-diacetate (vinyl glycol diacetate), formed in small amounts, is an intermediate product in the synthesis of vitamins and other biologically active compounds.

A known method for producing butandiol diacetate by reacting butadiene with oxygen and acetic acid in the presence of a solid palladium-containing catalyst in the liquid phase when fj is heated. The main disadvantage of carrying out the reaction in the liquid phase is the low reaction rate.

The technical essence and the achieved result most closely resembles the method for obtaining butandiol diacetate by reacting butadiene with oxygen and acetic acid in the liquid or gas phase on a solid palladium catalyst containing alkali metal salts as activators at 50-2 ° C and atmospheric pressure.

The disadvantages of this method are the formation of an undesirable by-product, α-acetoxy, 3-butadiene, and the necessity of carrying out the reaction with low concentrations of butadiene at a low rate so that the catalytic activity of the catalyst does not decrease.

The goal invented is the teaching of butandioldiat. high yield tatoa and reaction acceleration.

The goal is achieved by the described method for the preparation of butandiol diacetate, which consists in the interaction of butadiene with oxygen and acetic acid in the gas or liquid phase on a solid supported catalyst containing h. Platinum c. the amount of 1-20 wt.% and one of the elements 5 or 6 of the main subgroup of the Periodic Table e of the 1 in the amount of 0.05-10 weight. % and the rest up to 0 (; carrier, and the process is carried out at a temperature of 70–140 ° C and a pressure of 1–35 atm.

Distinctive features of the method include the use as a catalyst containing platinum and one of the elements 5 or 6 of the Mernodic system of elements on the carrier, as well as carrying out the process at a pressure of i-35 at.

The technology of the method is as follows.

In an aqueous solution of platinum chloride or another compound of platinum and one or more compounds of phosphorus, mouse ka-, antimony, bismuth, tellurium and selenium the carrier is dispersed, then the water is evaporated and the resulting mass is reduced with gaseous hydrogen or methanol vapor. The catalyst can also be obtained by mixing the carrier and solution with a precipitant (for example, an alkaline agent), followed by the above-described reduction. Platinum and antimony, phosphorus, mouse, bismuth, tellurium, or selenium are deposited on the carrier successively or simultaneously. It is also possible to introduce the carrier as a soluble compound and precipitate it together with the active metal.

A suitable carrier is activated carbon, which can be activated, for example, by treatment with an acid. The concentration of platinum on the carrier 1-20 wt.%.

Halides, nitrates, sulfates, oxides and other compounds of arsenic, antimony, bismuth, tellurium and selenium are also used to prepare the catalyst. Ortho-and metaphosphoric acids, alkaline and alkaline-earth phosphates are used as phosphorus-containing compounds. The amounts of phosphorus, arsenic, antimony, bismuth, tellurium, and selenium compounds on the carrier are within the range of 0 05-10 weight. % Particularly preferred are ilatin catalysts containing activated carbon as a carrier, 0.1-10% platinum (relative to the total weight of the catalyst) and about 0.1-5% tellurium or antimony ....

An increase in platinum concentration does not bring economic benefits, since it does not increase the yield and degree of conversion of olefins in proportion to the increase in metal concentration.

. The catalyzed reaction can be carried out by any known method, continuously or periodically, for example, with a fixed bed, a fluidized bed, a three-phase fluidized bed, etc. If the reaction mixture is liquid, and butadiene and oxygen are partially dissolved and partially in liters, it is advantageous to use a fixed catalyst.

When carrying out the reaction in the gas phase, the temperature is usually 100-140 ° C, and the pressure is i-35 atm. When the reaction is carried out in the liquid phase, the temperature is 70-110 ° C, the pressure is I-35 ata.

Example 1. 25 mmol (8.43 g) of platinum chloride and 25 mmol (3.99 g) of tellurium oxide are dissolved in 200 ml of 6N. hydrochloric acid, then 50 g of activated carbon with a diameter of (0.1–0.4 mm), previously boiled with 5/1 g of azogram acid, are added, and slowly evaporated on a wave bath to dryness. After additional su)

For 2 hours in a stream of nitrogen at 150 ° C, nitrogen, saturated with methanol at room temperature, is passed through the residue at a rate of 5 l / min for 4 hours at 200 ° C and for 2 hours at 400 ° C.

25 g of the obtained catalyst and 540 g of acetic acid are introduced into a flask with a stirrer. A mixture of 3 nl / h of butadiene and 3 nl / h of oxygen is then passed at 85 ° C. After 4 h, the reaction is stopped, the catalyst is filtered off, the solution is concentrated and distilled. With a butadiene conversion of 33%, 36.8 g are obtained.

diacetate. The distillate consists of 81.2% 1,4-diacetoxybutene-2 and 18.8% 3,4-diacetoxybutene-1.

Example 2. 250 mmol (84.3 g) chloride

0 platinum and 32.5 mmol (5.2 g) of tellurium oxide are dissolved in 2000 ml of bn. hydrochloric acid, 500 g of activated carbon is added to the solution obtained and slowly evaporated on a water bath to dryness. Thereafter

5, the reaction was carried out as described above. 370 ml {144 g) of the catalyst obtained is placed in a tube (32 mm diameter, 50 cm long) with a double jacket. Then at 130 ° C water t 10.5 nl / h of butadiene, 10.5 nl / h of oxygen and 250 g of acetic acid in the form of steam. The temperature of the latter is J30 ° C. Every hour, a sample is taken and distilled. Analysis of the distillate shows that more than 99% of butandiol diacetate is formed.

Yield, g / kg of catalyst h (g / l) of butene; 5 .2-diol-1,4-diacetate over 4; 11 and 32 hours are 43 (17), 43 (17) and 42.5 (16.7), respectively.

Example 3. 36.28 g of platinum chloride, 21.65 g of tellurium dioxide and 7 | 78 g of antimony chloride are dissolved in 4 g of 6N. hydrochloric acid, then 1 l (450 g) of activated carbon (2 mm in diameter), previously boiled with 15% nitric acid, is added and slowly evaporated on a water bath. After the preliminary

5 drying for 5 hours at 150 ° С is dried as in Example 1, and then it is reduced to 19 hours at 200 ° C and 40 hours at 400 ° C.

1 liter of catalyst is introduced into a reaction tube 4000 mm long and 20 mm in diameter.

° Install glass rings with a diameter of 3 mm above the contact. After that, at 30 at and 95 ° C, 0.7 l / h of butadiene (in the liquid state), 14.4 l / h of acetic acid and 130 nl / h are passed through the catalyst.

5 oxygen. The amount of the latter is adjusted taking into account the flow rate to a constant end of the 1 {traction in a circulating gas of 5 vol.%, With additional circulates above the contact; 74.3 l / h (under pressure). The outlet of the 11th mixture from the reactor is divided into gaseous and liquid components, the pressure of the liquid is reduced, and the gas is circulated.

After 200 hours at a constant degree of conversion, the yield of the desired product is 300 g of diacetate per I l of catalyst per hour. The reaction product consists of L7.1% butadiene-1-diol-3, 4-diacetate and 80% of a mixture of cis-n g / 7an-butene-2-diol-1,4-diacetate.

Example 4. 44.4 g of platinum chloride and 31.9 g of tellurium oxide are dissolved in 4 liters of 6N. hydrochloric acid, then 1.4 l (510 g) of activated carbon (1.5–2.5 mm in diameter), previously boiled with 15% hydrochloric acid, are added and slowly evaporated on a water bath. After pre-drying for 5 hours at 150 ° C, the catalyst is reduced with hydrogen (100 l / h) at 200-250 ° C for 10 hours.

1 l of catalyst is placed in the apparatus described in Example 3, and at 95 ° C and 30 ° C this is added 6.0 l / h of acetic acid, 290 ml / h of butadiene and (30 l / h of oxygen;

8.0 l of liquid and 3.2 n / m gas / h are reirculated. The maximum concentration of butadiene in the circulating flow is 1.1 ° / o. The reaction system is outside the explosive limits of the mixture of oxygen and butadiene.

When carrying out the method for 170 h, diacetates are obtained with an average yield of 500 g / l / h. The product consists of 13.5% butene-1-diol-3, 4-diacetate and 85% butene-2-diol-1, 4-diacetate,

Examples 5-12. Analogously to Example I, platinum chloride and a promoter (the proportions are shown in the table) are dissolved in hydrochloric acid and a catalyst is obtained as described above. The carrier in all cases is activated carbon. 25 g of the catalyst thus obtained and 540 g of acetic acid are reacted with a mixture of 3 nl / h of butadiene and 3 nl / h of oxygen at 85 ° C for 4 hours. The processing is carried out as in Example I and the products shown in the table are obtained.