CS260295B1 - Method of 2,2-dialkoxypropane production - Google Patents

Abstract

The process for producing 2,2-dialkoxypropane is carried out two-stage so that a mixture of hydrocarbons containing alene and methylacetylene v 2 to 98 wt. (10 to 45%) are at a temperature of 100 to 250 ° C (100 to 220 ° C) Celsius) to react with at least one aliphatic alcohol C 1 to C 5, optionally also with water additives, for catalytic effect metal compound I.a and / or subgroup II.b. periodic system (divalent salts mercury, zinc, cadmium, hydroxides or alkali metal salts); ratio alcohol (s): alene with methylacetylene - 1: 6 to 6: 1 and a pressure of 0.1 to 1 MPa. First-stage reaction product, mainly after separation of hydrocarbons and optionally delivery additional amounts of acetone and alcohol are added leads to the second level. In this at -50 to 35 ° C with acidic contact condensation occurs (cation exchanger in H-form) and 2,2-dialkoxypropane is usually isolated.

Description

The process for the preparation of 2,2-dialkoxypropane is carried out in a two-stage process such that the hydrocarbon mixture containing alene and methylacetylene in an amount of 2 to 98% by weight. (10 to 45%) is reacted at 100 to 250 ° C (100 to 220 degrees Celsius) with at least one C 1 to C 5 aliphatic alcohol, optionally with water admixtures, with the catalytic effect of the metal compound Ia and / or II b of a subset of the periodic system (divalent mercury, zinc, cadmium, hydroxide or alkali metal salts), at an alcohol (s): alene molar ratio with methylacetylene - 1: 6 to 6: 1 and a pressure of 1 to 1 MPa.

The reaction product of the first stage, mainly after separation of the hydrocarbons and optionally addition of additional amounts of acetone and alcohol, is passed to the second stage. In this case, at -50 to 35 ° C with acid contact (cation exchanger in the H-form), condensation takes place and 2,2-dialkoxypropane is usually isolated.

280295 .2 6 D 2 9 S

The present invention relates to the preparation of 2,2-dialkoxyproipane in which the alkoxy groups are 1-5 carbon atoms, from available petrochemical feedstocks under relatively mild reaction conditions and employing low-tech catalysts.

Dialkoxypropanes increasingly find application not only as final products, but also intermediates in organic syntheses, including industrial organic synthesis. Thus, dialkoxypropanes by heating with low porous alumina yield isopropenylalkyl ethers (Romanian Pat. 79 846; Banciu M., Popescu A .: Bul. Inst. Politech. "Gheorghe Gheorghiu" - De] "Bucuresti", ser. Chim. - metal. , No 1, 101 (1980)) and on a high porosity at a temperature of 275 to 500 degrees Celsius to hexamethylbenzene.

Different reactions with the compounds of the formula MesSiMn (COs) are also given by the action of carbon monoxide (Gladysz J.A., Marši M .: Organometallic 1, 1 467 (1982)); Tetrahedron Lett. 23, 631 (1982)); However, dialkyl ketals are prepared by reacting ketones with alcohols in the presence of acidic condensation catalysts in (U.S. Pat. No. 2,827,494) and co-impregnating 2.5-5 moles of anhydrous copper sulfate per mole of ketone.

Thus, in the case of the preparation of 2,2-dimethoxypropane, e.g. from 11.5 moles of acetone and 23 moles of methanol with a catalytic effect of 1 mole of hydrochloric acid and the action of 30 moles of anhydrous calcium sulfate, the main product is obtained in 87% yield (patent application pending NSR 2,636,278). The rate of formation of 2,2-dialkoxypropane from acetone and methanol was investigated in the presence of various catalysts, including 1- (dialkylamino-1-methoxycarbenium methoxysulfates) (Kantlehner W., Gutbrot H. D., Liebigs Ann. Chem. No 2, 246 (1980)).

It has also been shown that to separate the individual components of the reaction mixture (acetone, water, methanol, 2,2-dimethoxypropane) prepared by

2,2-Dimethoxypropane requires extraction or azeotropic distillation (Bruner E., Scholz A .: Chem. Ing. Techn. 52, No 2, 164 (1980); Berg's VV, Andrianova ON: Chim. No. 4, 454 (1983)).

However, these processes require acetone as a raw material in addition to methanol. Finally, 2,2-dialkoxypropane as a reactant in the preparation of 2,2-dimethyl-4-hydroxy-1,3-benzodioxole from pyrogalol was prepared from 2-alkoxypropene by reaction with methanol in an inert solvent, in particular toluene, xylene or tetrachlorethylene at temperature 10 to 60 ° C under the catalytic action of a strong acid cation (V. Brit. Pat 1386 094). However, the process requires pure 2-alkoxypropene.

According to the invention, there is provided a process for the preparation of 2,2-dialkoxypropane of the general formula

OR ¹ /

(CH 3) 2 C

OR ² in which R ¹ and R ² = alkyl C 1 to C 5, wherein R ¹ and R ² may be the same or different, is carried out such that the hydrocarbon mixture containing the alene and / or methylacetylene in an amount of 2 to 98 wt. is reacted with at least one C 1 -C 8 aliphatic alcohol or at least one C 1 -C 5 aliphatic alcohol with admixtures of 0.01 to 25 percent by weight. water under the catalytic action of at least one metal compound of the I. and / or II.b subgroup of the Periodic Table of the Elements at a temperature of 100 to 250 ° C, a molar ratio of alcohol to total alene and / or methylacetylene content of 1: 6 to 6: 1; 1 to 1 MPa, wherein the reaction product as such or after separation of hydrocarbons, including unconverted alene and / or methylacetylene, containing mainly acetone, unconverted alcohol or alcohols, 2-alkoxypropene or a mixture of 2-alkoxypropenes, leads to condensation at -50 up to 35 ° C with the addition of an acid catalyst or a combination of an acid catalyst and a basic catalyst.

The advantage of the process according to the invention is the raw material availability, production can be done without acetone, the possibility to evaluate a relatively wide range of hydrocarbon mixtures containing alene (1,2-propadiene) and methylacetylene (propyne). Then, it was surprising to find that if the intermediate is a mixture of 2-alkoxypropene, methanol and additionally acetone, the high condensation rate is at low temperatures, ensuring high conversion and selectivity even without scavengers. water.

The process for the preparation of 2,2-dialkoxypropane is carried out in two stages, where in stage 1 a mixture of methylacetylene with propadiene and methanol produces 2-alkoxypropropene and, in part, acetone:

CH3CsCH cat.

+ CORNER --- ►

CH 2 = C = CH 2

CH2 = C-CH3 + CH3-C-CH3.

I II

OR O

In the second step, the mixture of alkylisopropenyl ether and acetone in an alcohol is usually converted to the desired 2,2-dialkoxypropane at low temperature after separation of the hydrocarbons on a strong acid catalyst such as a strong mineral acid, a sulfonated ip polymer or a copolymer, optionally combined with a basic catalyst (anion exchange resin).

CH2 = C-1CH3

I

OR

-j-2 ROH <: '

CH 3 -C-CH 3

ABOUT

CH3 OR

.........- -......> \ /, 2C 4 HzO, / \

CH 3 OR, which can either be concentrated or isolated in the purified state.

The first stage of production is based on an alcohol or a mixture of alcohols C1 to Cs and a mixture of hydrocarbons containing an alene (1,2-propadiene) and, as a rule, also methylacetylene, most often so-called methylacetylene. % residual G3 fraction from gas separation, containing 2 to 55 wt. mixtures of allene with methylacetylene. The reaction is preferably carried out in a steam or a steam bath. in the gas phase on the solid catalyst at a temperature of 100 to 250 ° C, most preferably in the temperature range of 180 to 220 ° C, depending on the type of catalyst used. The process is carried out at a pressure of 0.1 to 1.0 MPa, preferably at a pressure of 0.2 to 0.6 MPa. A space or contact time of 5 to 35 s ^-1 , preferably 8 to 20 s ^1, and a molar ratio of alcohol: methylacetylene with alene = = 1: 6 to 6: 1, preferably 3 to 1: 1, are chosen.

Suspended but preferably solid catalysts in the bed, if appropriate, in fluid form are suitable for the first step, and as active ingredient they comprise at least one metal compound of the I and the subgroup and / or II.b of the Periodic System, preferably II.b of the Periodic System elements or mixtures of group I and group II.b of the subgroup. They are most preferably based on zinc, cadmium and mercury and media, most often in the form of inorganic and / or organic salts.

Catalyst precursors (metals), i.e. metals, e.g. alkali metals, since catalytically active compounds are rapidly formed therefrom under the reaction conditions of the process. The active ingredient is most often applied to carriers of neutral, alkaline, but most acidic nature, e.g. on activated carbon, on alumina, in particular γ-alumina, on aluminosilicates, natural and especially synthetic zeolites, organic sulfonated polymers, i.e., ionites, especially caionites, such as sulfonated styrene-divinylbenzene copolymer copolymer, sulfonated polypropylene and the like. In this case, catalysts of an acidic nature, such as e.g. a mercury compound deposited on a strong cation exchange resin (a sulfone copolymer styrene-divinylhenzene resin, having approximately half - SO 3 H groups bound Hg ²⁺ ions.

Catalysts of this type are used in

1) the synthesis step, preferably at a temperature of 100 to 130 ° U. Conversion of methylacetylene with an allene of about 30% produces mainly acetone, its molar ratio to 2-alkoxypropene in the product being 10 to 20: 1.

Another type of solid catalyst used in the first stage of the synthesis of 2,2-diolkoxypropane of the present invention is the zinc or cadmium salts with organic acids, or mixtures thereof, supported on supports, e.g. on activated carbon. Particularly suitable are acetates, propionates, butyrates, zinc naphthenates, cadmium and mixtures thereof. The content of these salts in the catalysts is in the range of 10 to 40% by weight, most often 25 to 35% by weight. These catalysts are optionally combined with alkali metal hydroxides.

Catalysts of this type are mainly worked at temperatures in the range of 170 to 230 ° C. The reaction mixture typically contains 15 to 40 wt. % Of 2-alkoxypropene (alkylisopropenyl ether) and 20 to 5 wt. acetone. Unreacted methylacetylene with allene is recycled or returned to the pyrolysis together with the remainder of the C3 fraction. In extreme cases, they are used as fuel.

The second stage of the preparation of 2,2-dialkoxypropane is carried out by acid-catalyzed conversion of the reaction mixture from the first step, where both acetone and alkylisopropenyl ether (2-alkoxypropene) with alcohol react to 2,2-dialcopropane. aluminosilicates, particularly activated, such as bleaching clay, activated natural and synthetic zeolites, etc. Furthermore, organic sulfoacids, but in particular sulfonated polymers and copolymers, such as sulfonated styrene-divinylbenzene copolymer copolymer in H-form and the like. or goal type, converted to H-form in a standard manner.

A suitable reaction temperature in the second step is -50 to 35 ° C. Since the reaction is equilibrium and proceeds relatively quickly, a contact time of 5 to 30 min is usually sufficient. Although the reaction rate increases with temperature, the equilibrium concentration decreases

2,2-dialkoxypropane in the reaction mixture. Therefore, it is preferred that the residual acidity of the reaction mixture be neutralized by conventional bases, most preferably by means of anion exchangers, respectively. anionite.

This achieves stability of the composition of the product at temperature increase, storage and isolation of the components. Said neutralization is most conveniently carried out by passing the reaction mixture which leaves the catalyst layer at the synthesis temperature through a thick anion exchange layer converted into the active form in a conventional manner.

260295 In view of the equilibrium of the reaction, it is advantageous to remove 2,2-dialkoxypropane and water from the reaction mixture. Of relatively high purity, 2,2-dialkoxypropane can be isolated from the reaction mixture after the second stage of synthesis by extraction with a suitable alkali metal hydroxide solution and optionally 2,2-dialkoxypropane by distillation under reduced pressure. Also suitable are rectification or especially distillation processes (Bersg VV et al., Chim. Pharm. No. 17, 454 (1983); Brunner E. et al., Chem. Tech. 52 (2), 164 (1980)). ).

For the production of 2,2-dialkoxypropane, it is possible to use both C1-C8 individual alcohols and mixtures thereof, optionally with admixtures of other oxygen compounds and hydrocarbons.

In the first and second stages of the process of the present invention, it is appropriate to provide inhibitors and intermediates in the intermediate radical reactions. The production process in both stages can be carried out in a continuous, semi-continuous manner, but a continuous process is most suitable.

Further data on carrying out the method of the invention as well as other advantages are evident from the examples.

EXAMPLE

A pressure flow reactor of 15 cm ³ volume, equipped with pressure and temperature control, is charged with 9.8 g of catalyst containing 23.1 wt. zinc acetate on activated carbon.

Activated carbon has a specific surface area of 750 meters ² / g, a maximum pore with a radius of about 100 mm and a total pore volume of 0.36 cm ³ / g. The activated carbon used has a grain size of 0.36 to 0.63 mm and a specific surface area

229 m ² / g. After the air has been purged with nitrogen, the reactor is heated to 160 ^DEG C. and 7.0 cm @ ³ / h of liquid methanol are metered in by means of a pressure pump and 5.5 dm @ ³ / h of C3 gas fraction from the pressure vessel.

The C3 fraction contains a total of 31 wt. of allyl acetylacetylene. The system pressure is maintained at 0.6 MPa. After the conditions have stabilized for about 1 hour, the temperature in the reactor is gradually adjusted to 180-185 ° C. During the synthesis, a methanol: mole ratio was maintained in the feed.

: methylacetylene with propadiene at 2.5 to 2.8: 1. After 3 hours of steady-state operation, the degassed product sample contains (wt.%) 7.0 2-methoxypropene, 8.1 acetone, 0.5 hydrocarbons and the remainder is methanol. During long-term operation, as the activity of the catalyst decreases, it is desirable to gradually increase the temperature in the reactor to about 100 ° C

230 DEG. However, as the synthesis temperature is further increased, there is a strong decrease in catalyst activity due to the formation of polymers at its active centers.

The reaction mixture of the first stage of the synthesis, having the above composition, kept in the reservoir at a temperature of -5 ° C, is fed by a piston pump at a rate of 465 g / h to the top of the vertical situated reactor via a cooling coil immersed in a thermostat. The stainless steel cooling coil has an inner diameter of 3 mm and a tempered length of 6.5 in. The glass jacketed reactor has an internal diameter of 19 mm and a length of 90 cm. The lower part is filled with 50 cm ^{3 of} anicite (anion exchanger Ostion AD in OH-form), the upper part of the filling is 150 cm ^{3 of a} strong cation (cation exchanger Ostion KS v. I-form) in the active form.

All submerged pipe sections and the reactor itself are well insulated.

In a thermostate filled with ethanol, a temperature of -37 ° C is maintained. At the same time, the cooling medium from the thermostat is circulated through the jacket. reactor, thereby maintaining a temperature of -25 ° C at the top of the reactor. From the bottom of the reactor, the reaction mixture is continuously discharged into the container through an external vented overflow at a height of about 4 cm above the upper limit of the k-atex layer.

The ratios in the reactor, including the conversion, were stabilized after passing about 300 cm ^{3 of the} reaction mixture through a catalytic catalyst. The product obtained after stabilization of the conditions in the reactor contained (% by weight) liquid-gas analysis of 0.1 methylisopropenyl ether, 17.3 2,2-dimethoxypropane, 3.8 acetone and 76.8 methanol, as determined by liquid-gas chromatography. corresponds to a conversion of methoxypropene of 98% and acetone of 52%. In addition, hydrocarbons and water are present in the product.

Example 1 -a d 2

The synthesis of 2,2-dimethoxypropane is carried out in the first and second steps in a similar manner to that described in Example 1. However, in the first synthesis step, 9.8 g of a mixed Cd-Zn catalyst having a grain size of 0.36-0.63 mm are used. . This catalyst is prepared by applying 11.5 wt. cadmium acetate and 11.5 wt. of zinc acetate on activated carbon of the same type as in Example 1. 5.7 cm ³ / h of liquid methanol and 6.0 dm ³ / h of gaseous C3-fraction are added to the reactor, which corresponds to a molar ratio of methanol: methylacetylene with propadiene = 1 , 9: 1.

The reactor maintains a pressure of 0.55 MPa and a temperature of 180 ° C, which, however, can be gradually increased to 220 ° C over a long period of time in order to maintain a constant conversion. The degassed synthesis mixture per reactor contained (w / w) 30.1 of 2-methoxypropene, 2.0.2 of acetone and 0.45 of hydrocarbons in methanol. This mixture is fed through the second stage of synthesis at a rate of 96 g / h through 150 cm ^{3 of a} strong cation exchange resin in the H-form (Wofatit Ok-80, macroporous type) and 50 cm ^{3 of} anion exchanger Wofatit SBK.

The thermostat maintains a temperature of -3-8 ^? C on the bottom of the reactor ^and -30 C. The product comprises (% wt.) In addition to hydrocarbon and water f 2-methoxypropene, 2,2-dimethoxypropane 58.3, 11.5 26.7 acetone and methanol.

. "69295

The conversion of 2-methoxypropene is practically 100% and the conversion of acetone is 42%.

Example 3

The procedure is similar to that of Example 1 and 2 in the same apparatus. In the first step of the synthesis, 13 g of an ion exchange resin catalyst and a feed of 3.0 cm ³ / h of liquid methanol and 5.5 dm ³ / b of gaseous pyrolysis gas are used. fraction at 0.4 MPa and reactor temperature 120 ° C. Methanol: mole ratio

The propadiene methylacetylene is 1.1: 1. The catalyst is prepared from a cation exchanger Ostion KS and artichoate chloride or sulfate by replacing 50% of the H ⁺ ions with Hg ^{with +} ions. The resulting reaction mixture after degassing contains (by weight) 10.0 acetone and 0.5 hydrocarbons, the remainder being methanol.

The reaction mixture from the first stage of synthesis is fed at a rate of 470 g / h through 150 cm ^{3 of} cation exchange resin (Ostion Ks) in H-form and 50 cm ^{3 of} anion exchange resin (Ostion AO) at thermostat temperature of -44 ° C and top of reactor -31 ° C. The product contains (by weight) 10.7 2,2-dimethoxypropane, 3.9 acetone, 83.1 methanol, water and hydrocarbons, corresponding to conversion! acetone 60%,

Example 4

Using the same equipment and in a similar manner as in Examples 1-3, the first stage injects 7.0 cm ³ per hour of liquid methanol and 5.5 dm ³ / h of pyrolysis C3-fraction (mole ratio of methanol: methylacetylene with propanediene). is 2.6: 1 per 9.8 g of catalyst having a grain size of 0.36 to 0.63 mm and a specific surface area of 229 m ² / g. The catalyst is prepared by applying 30 wt. cadmium acetate onto the carbon of the same type as in Example 1. At a pressure of 0.55 MPa and at 180 ³ C to give a product containing (wt.%) 20.0 2-methoxypropene, 7.0, and 0.48 of acetone hydrocarbons in methanol. As the activity of the catalyst decreases, the reaction temperature can be gradually increased to 200-220 ° C.

The product of the first stage of synthesis is passed through a 150 cm ³ thick cation exchanger in the H-form of the goal type Vartou KS and 50 cm ³ anion exchanger Varion AD at a temperature of -4 'degrees Celsius in a thermostat and -31 ° C at the top of the reactor. .

The resulting mixture contains (wt%) 0.24 2-methoxypropene, 32.91 2,2-dimethoxypropene, 4.49 acetone, 61.07 methanol, water and hydrocarbons. The conversion of 2-methoxypropene is 99%, the acetone conversion is 35%.

Example 5

The zinc and cadmium catalysts described in Example 2 are charged to the pressure apparatus described in Example 1. The procedure is similar to that of Example 1, but after the reactor has been heated to 160 ° C, 15 cm ³ / h of liquid butanol are started. 5 dm ^{3 of} C3 gas fraction from pressure tank. The composition of the C3-fraction is also given in Example 1. The pressure in the reaction system is maintained at 0.6 to 0.65 MPa. After reaching steady state conditions the temperature of 180-185 ° C for 1 h and was increased to 200-220 DEG C. After ³ hours a further 3 to settled continuously) operation of "degassed" vzorrka product contains (wt.%) 20.2 2 (n -butoxy] propene, 15.3 acetone, and 0.35 hydrocarbons in n-butanol.

This mixture is fed over 150 cm ^{3 of} strong acid cation exchanger and 50 cm ^{3 of} anion exchanger (both ionites specified in Example 2) at a rate of 100 g / h in the second stage of synthesis. The reaction temperature is maintained at -30 to -28 C. The product contains traces of 2- (n-butoxy jpropene, 25.5 2,2-di- (n-butoxy jipropane) and 10% by weight) in addition to hydrocarbons and water. The conversion of 2- (n-butoxy) propene is practically 100% and acetone is 35.2%.

Example 6

The catalyst specified in Example 4 is charged to the high pressure microreactor described in Example 1. Similar to Example 1, 7.0 cm ³ / h of methanol, 11 dm ³ / h of pyrolysis C3-fraction (mole ratio of methanol: methylacetylene: alene) are charged. = 1.3: 1) at a pressure of 0.55 MPa and a reactor temperature of 180 ³ C. During a long run of the reactor, the temperature can be raised to 200 to 220 ^? C. In the "degassed" reaction mixture, 2.2 wt. % acetone, 10.3 wt. 2-methoxypropene. and 0.4 wt. hydrocarbons.

The product from the first stage of the synthesis was cooled to -40 degrees Celsius in a batch reactor and 3% mole was added. p-toluenesulfonic acid monohydrate, calculated together with acetone and 2-methoxypropene. The reaction mixture was stirred under the above conditions for 3 h. The reaction is terminated by neutralizing the catalyst with potassium hydroxide in a 10% excess. The acetone conversion reached 16.6% and the 2-methoxypropene 91.8% to the 2,2-dimethoxypropane formed. Similar results in the second stage are obtained with. the use of mineral acids, in particular sulfuric acid, phosphoric acid, and also boron trifluoride methanolate as catalysts.

Example 7

The procedure is similar to that of Example 0, except that the product from the first stage synthesis in the batch reactor is replaced with 3% mol. p-toluenesulfonic acid monohydrate add 0.5 mol%. sulfuric acid and 2% mol. trihydrogenphosphoric acid. Acetone conversion reached 17.4% and 2-methoxypropene 92.7% to 2,2-dimethoxypropane.

Example 8

Using the same apparatus and procedure as in Examples 1-3, using 10 g of a catalyst consisting of 40 wt. sodium hydroxide on activated carbon. Using the feed of the raw materials specified in Example 1, a product of the following composition is obtained (in wt.%): 11.1 wt. 2-methoxypropene, 4.2% acetone, 0.5% hydrocarbon. The remainder is methanol. The reaction mixture is further processed according to Example 1 by low temperature condensation. A product containing 0.2 wt. % Of 2-methoxypropene, 17.1 wt. % of dimethoxypropane, 3.6 wt. acetone and the remainder being methanol.

Example 9

Using the same apparatus and otherwise in a similar manner to that of Examples 1 to 3, only potassium hydroxide impregnated χ-alumina containing 30 wt. KOH. Using the feedstocks and process parameters as in Example 1, a product having the composition (in wt.%) Is obtained: 13.1% 2-methoxypropene, 2.2% acetone, 0.5% hydrocarbon and the remainder being methanol. The reaction mixture is further processed according to Example 1 by low temperature condensation to give a crude product of the following composition (in percent by weight): 0.1% 2-methoxypropene, 17.3% 2,2-dimethoxypropane, 3.7% acetone and the remainder being methanol .

Example 10

A similar apparatus and procedure was used as in Example 1, except that the feed methanol contained 0.5 wt. water. The intermediate obtained from step I contains (in% by weight): 3.1% 2-methoxypropene, 12.4% acetone, 0.6% hydrocarbons and the remainder methanol. The reaction mixture was treated according to Example 1 by low-temperature condensation to give a product (% by weight): 0.05% 2-methoxypropene, 15.5%

2,2-dimethoxypropane, 5.6% acetone and the remainder being methanol.

Example 11

The procedure is similar to that of Example 10, except that the acetone / methanol mixture is added to the intermediate by adjusting its composition to (in wt.%): 2.48% 2-methoxypropene, 21.9% acetone, 0.48% hydrocarbons and 75.1% methanol. The reaction mixture is treated according to Example 1 by low-temperature condensation, only a similar amount of sulfonated polypropylene having a grain size of 0.5 to 1 mm is used instead of the sulfonated styrene-divinylbenzene copolymer copolymer. The product of the composition (in wt.%) Is formed: 0.03% 2-methoxypropene, 28.4% 2,2-dimethoxypropane, 3.9% acetone and the remainder being methanol.

Claims (5)

EXAMPLE 8 The same apparatus is used as described in Examples 1 to 3, using 10 g of a catalyst consisting of 40 wt. sodium hydroxide on activated carbon. Using the feedstocks specified in Example 1, the product of this composition (in wt.%) Is obtained: 11.1 wt.%. 2-methoxypropene, 4.2% acetone, 0.5% hydrocarbon. The remainder consists of methanol. Further, the reaction mixture is worked up as in Example 1 by low temperature condensation. A product containing 0.2% by weight of 2-methoxypropene, 17.1% by weight, is obtained. % dimethoxy-propane, 3.6 wt. acetone and the remainder is methanol. EXAMPLE 9 Working on the same apparatus and in a similar manner to that of Examples 1-3, only γ-alumina-containing potassium hydroxide containing 30% by weight is used as the first-stage catalyst and process. KOH. Using sprays and technological parameters as in Example 1, the composition of the composition (in wt.%) Is 13.1% 2-methoxypropene, 2.2% acetone, 0.5% hydrocarbon and the remainder is methanol. The reaction mixture is further processed as in Example 1 by condensation to give the crude product of this composition (in percentages): 0.1% 2-methoxypropene, 17.3 12 percent 2,2-dimethoxyprapane, 3.7% acetone and the remainder being methanol. EXAMPLE 10 A similar apparatus is used and a similar procedure to that described in Example 1, except that the metered methanol contains 0.5 wt. The obtained intermediate from stage I contains (in% by weight): 3.1% of 2-methoxypropene, 12.4% of acetone, 0.0% of hydrocarbons, and the remainder being methanol. % by weight to produce a composition of composition (in% by weight): 0.05% 2-methoxypropene, 15.5% 2,2-dimethoxypropane, 5.6% acetone and residual methanol. as in Example 10, only a mixture of acetone and methanol is added to the intermediate so that its composition is adjusted to (in% by weight): 2.48% 2-methoxy-propene, 21.9% acetone, 0.48% The reaction mixture according to Example 1 is treated with a lower temperature condensation, using a similar amount of sulfonated poly (propylene) of 0.5 to 1 mm instead of the sulfonated co-polymeric styrene-divinylbenzene resin. : 0.03% 2-methoxypropene, 28.4% 2,2-dimethoxypropane, 3.9% acetone and the rest are methanol. MET A process for producing 2,2-dialkoxypropane of the formula OR 1 / (CH 3) 2 C OR 2 wherein R 1 and R 2 = C 1 -C 8 alkyl, wherein R 1 and R 2 may be the same or different, characterized in that the hydrocarbon mixture containing the alene and / or methylacetylene of 2 to 98 wt. is reacted with and mixed with one aliphatic alcohol Cž Cs Cs or at least one aliphatic C až Cs Cs s alcohol with admixtures of 0.01 to 25% by weight. water at a catalytic effect of at least one metal compound Ia and / or II.b subgroup of the periodic system at a temperature of 100 to 250 ° C, a molar ipomereal alcohol to a total alene and / or methyl acetylene content of 1: 6 to 6: 1 and a pressure of 0.1 to 1 MPa wherein the reaction product as such or after separation of the hydrocarbons, including non-maltone converted alene and / or methylacetylene, comprising mainly acetone, unconverted alcohol or alcohols, 2-alkoxypropene or a mixture of 2-alkoxypropenes is condensed at - &Lt; 50 to 35 ° C, to render the acid catalyst or combination acidic with a basic catalyst. 2. Process according to claim 1, characterized in that the hydrocarbon mixture is a residual C3-fraction from the separation of pyrolysis gases containing 2 to 55 wt. mixtures of alkene with ethyl acetylene. 3. Process according to claim 1, characterized in that the catalyst at the first stage of the reaction of the alene and methylacetylene with an aliphatic alcohol C1 to Cs or an aliphatic alcohol C1 to Cs with at least one straight chain is at least one metal compound of the first and second groups of the periodic system of elements preferably sodium hydroxide or potassium hydroxide on the carrier and / or subgroup IIb, preferably zinc oxide, cadmium oxide, zinc acetate, cadmium acetate, or a mixture thereof on carriers. 260295 13 4. A process for producing the compounds of claim 1, wherein further oxygenated intermediate, such as acetone, alcohol or 2-, is added to the reaction product of any or all of the hydrocarbons including non-converted alene and / or methyleneacetylene. and α-14 coxypropene and is condensed to a temperature of 5050 to 35 ° C. 5. The method of manufacture according to clauses 1 to 4, characterized in that the 2,2-dialkoxypropane formed is isolated, such as by extraction and / or recrystallization and / or extraction rectification.