SU577965A3 - Method of preparing alkenyl benzenes - Google Patents

Description

(54) METHOD FOR PRODUCING ALKENYLBENZENES

re-catalysis catalysate from the reaction products. C, On the other hand, if the amount of metallic potassium is less than the lower limit of m: above the range, the product cannot be obtained in good yield, even if the amount of metallic sodium is reduced.

If the amount of metallic sodium is above the indicated limit, the yield of the product decreases, and the amount of unwanted by-products increases. On the other hand, if the amount of metallic sodium is below the specified interval, then the yield of the extension is significantly reduced.

If a catalyst consisting of metallic potassium and sodium is used as an alloy, the latter is obtained by mixing the metals in the molten state in the absence of oxygen and moisture.

The alloy can be obtained by heating metallic sodium and potassium compounds such as its oxide, carbonate, hydroxide, or halide derivative. The catalyst may be supported on a carrier. Such carriers as graphite, NajO, KjO, CaO, HdO, BaO, NaCI, KCt.KF, KBr, NajCOs, KgSy, SiO, Al, Fe can be used as carriers.

The starting alkyl benzenes are the compounds of the following form)

.RI.

p ff (G

where RI is an alkyl rpjoina having 1 or 2 carbon atoms;

Rj, Yaz, and R4, which may be the same or different from Rj and RS, are hydrogen or a group with 1 to 3 carbon atoms. Preferred alkyl benzenes are toluene | xylene, zhenylbenzene, trimethylbenzene and tetramethylbenzene.

Typically, the reaction is carried out at 90-200 °, preferably PO-180 ° C. The reaction can be carried out under reflux conditions.

The molar ratio of 1,3 - butadaene and alkylbenzene can be arbitrarily chosen from known ratios. Thus, the molar ratio of millbenzene and 1,3 - butadiene can be 1: 0.0011 .0.4,. preferably 1: 0.01 - 1: 0.3 and better than 1: 0.05 - 1: 0.2. The reaction can be carried out in continuous and batchwise ways. In a continuous process, multiple reaction zones can be used, preferably of an overflow type. Typically, the reaction time is from 3 minutes to 10 hours, preferably from 10 minutes to 8 hours;

Most preferred are semi-periodic and continuous methods. In a continuous process, both a closed-flow system and a column type counter-flow mixed reactor can be used. Preferred in the continuous process is the so-called cross-reacting method.

a current that includes, as an indispensable condition, a plurality of reaction zones through which the reaction liquid passes sequentially from the initial to the final reaction zone, while 1,3-butadiene is supplied in portions in the respective reaction zones.

The amount of metal catalyst consumed is measured and calculated as follows.

1. After completion of the reaction and while stirring the reaction mixture is continued, a certain amount of it is taken for analysis. To this liquid (A, g) is added 20% of the weight taken on anaLysis: the strengths of ethyl alcohol.

at room temperature. The amount of hydrogen gas evolved (B, cm) is then measured at 20 ° C and 1 atm.

Yao-quality metal catalyst (molG liquid reaction mixtures) count 1 From

on the basis of; measured values by the following equation Number of metal katal.tator

one

R..271

22LiQO 293

 2

2. About 0.5 g of the metal catalyst is taken from the liquid reaction mixture for analysis, after which 20 cm of ethyl alcohol are added,

to start the reaction. The reaction liquid is then analyzed by the atomic absorption method and the sodium to potassium ratio is determined.

From the results obtained in paragraphs 1 and 2, calculate the amount of C (g / g liquid product

reaction) metallic sodium and potassium in the reaction products.

3. The amounts of D metallic potassium and metallic sodium added again to the reaction system are theoretically determined as the amounts of metallic catalyst (g / g of the reaction product).

4. From the obtained results, the consumed quantities of E metal; | These 1 catalysts are determined according to the equation.

Claims (3)

Exit and cleaning. After filtration of the total reaction mixture, at room temperature, approximately 500 g of its 1-expel distillation on a Widmer rectifier under reduced pressure (on the order of 2 mm Hg) in order to divide it into a fraction, hydrate; i and 75 ° C (teperypa top of the distillation colosa.1), fraction 75-170 ° C, as well as the residue. Fractional 75-170 ° C is selected because it is an alkated product. This fraction is analyzed by gas chromatography in order to determine the content (wt.%) Of 5 - aryl - pentene -2 and 5 of arylentene - 1 yr 5 - arnl - hexene - 1, and then calculate the yield of the monoalkenne product — the content of unreacted alkylbeneopene in this fraction does not exceed 1% by weight of the fraction. 20 g of this alkylation products of alkenylation are distilled under reduced pressure (22 mm of r.st.) and at a reflux ratio of about 20 using an Oldershaw-type distillation apparatus, as a result of which 10 g of fractions containing a large amount of the target 1 product are obtained, followed by obtaining 2 g of the main fraction. It is analyzed by gas. Yield of the desired product (g) Yield% - Used 1,3 - butadiene (S. The S value is determined by the ratio of the yield of the target product obtained as a result of the reaction and the total sum of the weight of potassium and katri I in the reaction sphere The yield of the target product means the yield, counting on loading in a semi-periodic process, whereas in a continuous process it means the output of the resulting target product during the average residence time in the reaction zone.% M more S value, the smaller the amount of kata used per unit of formed monoalkylated product, thereby making it possible to remove the catalyst without the need for regeneration and reuse. On the other hand, the smaller the S value, the more the amount of the catalyst is used on the back of the resulting monoalkylated product, creating the need for reuse catalyst for economic considerations m. PRI me R s 1-7 and 8-10 and control experiments 1-6. In a stream of dry nitrogen (O content - 1 h, per 1 mln., Moisture content 0.5 hr. And 1 mln. By weight) metallic sodium (purity 99.92%, potassium content. Per 1 mln.) About 1.08 g (0.018% by weight, considering the original xylene) and metallic potassium (purity K 99.1%, sodium content 1.0%) in an amount of 0.252 g (0.0042% by weight, calculated on the original xylene) subjected to mixed smelting, as a result of which an alloy is obtained, to which 6000 g of practically anhydrous o-xylene is added, which is dehydrated by heating at refluxing in the presence of metallic potassium followed by a mixture of Niemi and distillation. The mixture is heated with stirring at 130 ° C under nitrogen for 1 hour, then 4 are added (10 g of 1,3-butadiene for 2 hours. After completion of the reaction and while stirring the reaction mixture, samples are taken to determine the spent catalyst. After cooling the liquid reaction mixture to 110 ° C (immediately) and, maintaining this temperature, stirring is stopped and the liquid reaction mixture is left for 30 minutes, after which it is separated into the catalyst phase and the phase containing the target product. the product is distilled at 22 mm Hg, selecting a fraction of 112-122 ° C, obtaining chromatography to determine the content (Ee.%). 5 aryl-pentene - 2 and 5 - arylpentene - I, or 5 -. Arylhexene - 2, or 5 - arylhexene - 1, which characterizes the purity of the product. Relative yield. The yield is determined on the basis of the yield of the target product found by the described method and the amount of 1,3-butadiene used in the reaction. The molecular weight of the target product is the desired product 5- (o-tolyl ) -penten-2. Its output (taking into account the selected sample) is 1046 g. The results obtained when carrying out the experiment in this way, but varying the amount of potassium and sodium, alkylbeisols, reaction temperature and reaction time, are shown in the table, along with the results given in Example 1 Example 11. A B70-liter reaction apparatus, equipped with a device for continuous mixing, is charged with 40 kg of practically anhydrous o-xylene and an alloy consisting of 8.0 g of metallic sodium and 2.40 g of metallic potassium. The reactor temperature was adjusted to 130 ° C and the mixture was stirred for 1 hour. Bezvodt 1J 1.3 butadiene and anhydrous xylene were introduced through the inlet at the bottom of the reaction vessel at a rate of 1.25 and 19 kg / h, respectively. The reaction product is viewed with appropriate gas content through a pipe laid in the central part of the reaction vessel so that about 45 kg of product remain in the reaction vessel at all times. The discharge of the liquid reaction product is carried out using a decanter which is a 10-liter container connected to the reaction vessel. The reaction liquid is transferred to a decanter and the upper layer of liquid is removed; . The catalyst separated in the decanter is continuously returned to the reaction volume. On the other hand, the suspension is a finely dispersed alloy (just from 2.25 g of sodium and 0.75 g of potassium per 1 kg of o-xylene 4) is fed into the reaction vessel at a rate of 1 kg / h. The experiment is carried out This procedure is carried out for 10 days. The upper layer of the waste liquid is distilled under reduced pressure (22 mm Hg) and the fraction boiling at I5-125 C is taken at a rate of 2.88 kg / h. The specific yield 1210; S 917.% stota 99.0%; yield 74.3%. Example 2. The same reactor is used as in Example 11, except that the reaction mixture is withdrawn from the system directly without decanting. Charged to the reactor 40 kg of anhydrous o xylene and 8.10 g of an alloy consisting of 6.75 g of metallic sodium and 1.35 g of metallic potassium, after which the temperature in the reactor is increased to 140 ° C, heating is continued for 7 hours at skewing The reaction is carried out for 30 minutes by blowing anhydrous 1.3 butadiene at a rate of 1.25 kg / h. Anhydrous scoop and anhydrous 1.3 butadiene are introduced into the reactor at a rate of 19 and 1.25 kg / h, respectively. A suspension of a finely dispersed alloy in the amount of 3.6 g, consisting of metallic sodium and potassium in the ratio of 5: 1 by weight, is introduced as a catalyst into the reactor at a rate of 1 kg / CKP o-xylene. The method is carried out according to the specified method within 2 days. The reaction pressure enters a separately provided 10 liter decanter. After the liquid containing the used catalyst has already been taken from the bottom of the decanter at a speed of 30 tons / hour, the clear liquid remaining in the upper part of the decanter is removed from the catalyst. The latter is subjected to vacuum distillation under reduced pressure (22 mm Hg) so as to obtain a) boiling water at 5-125 ° C at a rate of 2.99 kg / h. The specific output is 1,217; S value 794. Purity 99.5%; yield 77.2%. Example 3. A reconditioning vessel was used for a continuous process, made in the form of five tanks connected in series with agitators, each of which has a capacity of 800 ml (the capacity of an effective liquid load is 300 ml) and mounted so that the liquid from the first tank overflows the second through the overflow line, after which the liquid flows to the fifth reservoir and, finally, is discharged. In the first reservoir of this series of reaction tanks, anhydrous conallol is continuously fed at a speed of 600 g / h. Following this, the temperature in some tanks is increased to 130 ° C, the stirring speed is adjusted to 600 rpm, after which the alloy containing metallic sodium and potassium in a 1: 1 weight ratio is fed into the first tank using a microfilter. After 1 hour from the start of the supply of xylene and catalyst, anhydrous 1,3-butadiene is continuously introduced into each tank at a rate of 8 g / h. Thus, the reaction is carried out by the total introduction of 1,3-butadiene in an amount of 40 g / h . From the fifth tank in the px, the overflow of the latter overflows the reaction liquid CONSTANTLY enters the 1-liter flask. The temperature inside this flask is maintained at 110 ° C. Periodically, the catalytic phase is withdrawn from this part of the flask at a rate of 1 g / h, while at 1 h 637 g of pure liquid is withdrawn from the top of the flask. This pure liquid is vacuum distilled under reduced pressure (22 mm Hg) so as to obtain a fraction boiling at 115-125 ° C at a rate of 101 g / h. The specific output 5,402; the value of S 2,104. Purity 99.5%; yield 85.2%. 13 The claims of I. The method of producing alkenylbeneols by the interaction of an alkylbe aeol with 1, E butadiene at a psienhen temperature at an alkali metal catalyst, characterized in that, in order to simplify the process, a catalyst is used, which is treated with oxygen. 0.03 wt.% In terms of both alkylbioe and Schlich calc and metallic sodium kolmcho ctK, blended with the following cooi | Q 025-6.59 X Na | 0.0005, where X is the metal potassium used, ae.%. 4 L Oyusob pop. 1, representing ft with the fact that Aspolicy is used, containing O, 001-0.02 weights, (potassium in terms of alkylbeneol. 3. Selection according to claim 1, characterized in that it uses a catalyst containing an amount of maximal sodium in the amount of "tredelein versus" 0.025-0.59 X Na 0.001, where X has the meaning. A process according to claim 1, characterized in that the process is carried out at 90-200 ° C and with a molar content of alkylbeizol and 1.3 - butadium, equal to 1: 0.0.01 1: 0.4.