DE1138758B - Process for the preparation of conjugated diolefins - Google Patents

Description

The conjugated diolefins are known starting materials for the production of plastics and in particular synthetic rubbers through polymerization. They can be polymerized, copolymerized or with dienophiles, e.g. B. maleic anhydride, to intermediate products in the synthesis of plastics, Resins and synthetic rubbers are condensed. Condensations of this type include in particular the Diels-Alder condensations, for example in Organic Reactions, Vol. 4 (John Wiley ίο and Sons, New York).

The present invention relates to a method for the production of conjugated diolefins, in which a stream of oxygen or an oxygen-containing Gas at a temperature below 150 ° C into a liquid, one carbon chain of at least 4 carbon atoms containing olefin of the aliphatic or cycloaliphatic series for conversion it leads into its hydroperoxide, the formed Hydroperoxide by treatment with a decomposing agent or reducing agent at a Temperature of below 150 ° C transferred into the olefin alcohol, whereupon the latter after heating allows a dehydration catalyst to act at a temperature between 100 and 375 ° C and that formed diolefin isolated, which is characterized in that the degree of conversion of the Olefin keeps between 2 and 20% during the oxidation and that the olefin is not converted dissolved olefin hydroperoxide converted into the olefin alcohol.

The process can be very economical, starting from petroleum-derived olefins, which optionally can also be used in the form of olefin mixtures in a certain petroleum fraction are included. In addition, the reagents used are also inexpensive.

It is already known to convert olefins by means of molecular oxygen with conversion into olefin hydroperoxide, optionally using the hydroperoxide formed as initiator ("Angewandte Chemie", 69, pp. 313 to 321 [1957]). It is also known from the same literature reference and German patent specification 943 705 to reduce the olefins to the corresponding alcohols which, according to British patent specification 577 365, are dehydrated to diolefins. In "Angewandte Chemie", 69, p. 318 (1957), it is stated that hydroperoxides of alkyl aromatic hydrocarbons can be treated with decomposing agents, in particular with basic agents, and that this results in the formation of aldehydes and ketones from the primary production process
of conjugated diolefins

Applicant:

Institut Francais du Petrole,
des Carburants et Lubrifiants, Paris

Representative: Dr. F. Zumstein,

DipL-Chem. Dr. rer. nat. E. Assmann

and Dipl.-Chem. Dr. R. Koenigsberger,

Patent attorneys. Munich 2, Bräuhausstr. 4th

Claimed priority:
France of March 3, 1958 (No. 759 544)

Genevieve Clement and Jean Claude Balaceanu,

Paris,
have been named as inventors

and secondary hydroperoxides and of alkali salts of the hydroperoxides from the tertiary hydroperoxides results.

The present process differs from the known processes in that the degree of conversion the olefins is kept at a value between 2 and 20% in the oxidation reaction. at In a preferred embodiment, the method also differs from the known ones in that that the olefin hydroperoxides are treated with bases, resulting in olefinic alcohols, a result which could not be foreseen on the basis of the known methods.

According to the invention. Procedure is for example Cyclohexene converted into conjugated cyclohexanediene (cyclohexadiene-1,3) while it was after the known methods, especially those in which halogenated or hydroxyl or Acetoxy group-containing derivatives of cyclohexane are used, only mixtures of cyclohexadiene-1,3 and cyclohexadiene-1,4 are obtained could contaminated by dehydration and cracking products; these various minor

209 679/313

products are unusable and with different, Uses of the cyclohexadiene-1,3 harmful, z. B. in the polymerization or in Diels-Alder condensations.

The first stage of autoxidation of the olefin with an oxygen-containing gas takes place in liquid form Phase at atmospheric pressure by introducing the oxygen-containing gas into the liquid OMn, since this under the applied temperature conditions

In all cases the reaction temperature is below the boiling point of the mixture.

The autoxidation reaction is favored by the presence of initiators, more advantageously-5 wisely the hydroperoxide formed in the reaction performs this function. With one continuously performed procedure it is enough to concentrate of the reaction product in the reaction vessel to keep constant "to allow a certain initiator usually is in a liquid state. If this amount is present in the reaction mixture, where If not the case, then such a large partial pressure will, however, increase the rate of conversion in the oxygen or the oxygen-containing gas must be taken into account. The agile that the olefin speed under the operating conditions with which the olefin is introduced, remains in a liquid state. depends on the capacity of the reactor

The reaction temperature depends on the type 15 tion vessel and is set so that the hydrodes each olefin used. Temperatures above peroxide concentration in it remains constant. The 150 ° C are avoided, however, since the olefin hydroperoxide containing the hydroperoxide in this concentration is decomposed with the formation of an undesired reaction mixture at a rate. 20 of the reaction vessel and the hourly conversion reasons are not applied. In most of the degree of conversion of olefins in these hydroperoxides cases, the reaction temperature is between 50
and 125 ° C.

The oxygen partial pressure has no influence on
the speed of reaction when he is 25
exceeds the agreed minimum value, which depends on the
treated product varies, but in each case below
Vs atmosphere is. If an oxygen partial pressure of more than Vs atmosphere is used, there is therefore a guarantee that the reaction peroxides in the reaction vessel with y, then results in speed will not be restricted. There is no upper limit for the amount of the reaction oxygen partial pressure subtracted every hour, mixture D from the following equation, but for economic reasons it is always preferable to keep it at or slightly above the limit value below which there is a risk of 35
that the reaction rate is reduced.
Under these conditions and especially in the case
If light olefins are used, the total pressure is approximately the same as the vapor pressure of the

represents and the concentration of hydroperoxides in the withdrawn mixture is inversely proportional is.

If the weight of the liquid kept constant in the reaction vessel is denoted by P, the ratio of the hydroperoxides formed per hour to the total weight of the reaction mixture is denoted by χ and the constant concentration of the hydroperoxides

= ρ -

It is essential to keep the degree of conversion of olefins to hydroperoxides to a relatively low level Values, e.g. B, on the order of 2 to

ten olefin at the reaction temperature. With the same 40 to limit 20% to thereby every possibility Temperature, this total pressure can be reduced to eliminate the occurrence of side reactions, The reaction mixture is still liquid. Under these conditions it is possible to obtain yields remains, if one achieves a solution of the olefin in one of hydroperoxides, which is close to IQO%>, Higher boiling point solvents used. based on the consumed © olefin. In the With the help of such a solution it is possible in certain 45 practical implementation the conversion cases even possible the implementation at atmospheric degrees and the feed rates of the pressure to carry out, The here usable action participants with advantage in the way specified Solvents must meet two conditions: they are that one must remain the same in the reaction vessel once non-oxidizable and very general concentration of hydroperoxides in the I do not react under the work conditions, 50 order of magnitude from 2 to 20 * / »depending on the treatment. H. do not decompose or change, and if olefins are present, if the percentages obtained others they have to have a boiling point for products to be very pure.

that over that of the olefin employed and in The importance of maintaining a general is above 60 ° C. The degree of conversion between 2 and 20 ° / o is determined by the

The following experiments are shown for the solutions that meet these requirements.

agents include benzene and its man conducts one at a temperature of 75 ° C

Chlorine derivatives as well as with nitrobenzoi ¹ in a concentration stream of oxygen in 1 kg of liquid cyclohexene, which contains from 2 to ΙΟ ¹ "/» benzene (to prevent 0.8% cyclohexene hydroperoxide and prevent polymer formation). The amount of oxygen absorbed is correct as a function

If the olefins to be treated are like this, most of the time, one can derive the weight of the hydroperst is the case, a sufficiently high boiling point oxide, according to the theoretical yield possess (olefins with at least 6 carbon atoms, the following equation:

eg the methyl pentenes, cyclohexene, methylcyclo- q ^ + O -> CH ■ OOH

hexen, heptene and dodecene), the autoxidation β jo · g - * "β 9

derived in the liquid phase according to the invention 65.

driving can be carried out at atmospheric pressure. It is also determined periodically by adding

It is then sufficient if the applied oxygen is potassium iodide to a sample of the reaction mixture

amount is so large that the liquid phase is saturated. and determination of the released iodine with sodium

hyposulfite the amount of hydroperoxydine present in the mixture.

According to theory, the absorption of 1 mole of oxygen corresponds to the formation of 1 mole of hydroperoxide. Since oxygen is practically insoluble in the reaction mixture when it is. to no chemical If the reaction occurs, the total consumption of excess oxygen corresponds to the oxidation of the cyclohexene to undesired connections.

The selectivity of the reaction can therefore be expressed in each case by the following relationship:

Weight of the hydroperoxide formed / theoretical hydroperoxide weight

Salts which, in the presence of peroxides, change from a lower valence to a higher valence pass over.

To those used in the present process, preferably at a temperature between 0 and 4O ⁰ C decomposition catalysts include either metal in powdered solid state, such as cadmium, lead, tin, bismuth, silver, copper or a mixture thereof, or ίο heavy metal salts, z. B. the salts of cobalt, manganese, lead, copper, iron or mercury, or inorganic bases such as sodium hydroxide, potassium hydroxide, barium hydroxide or calcium hydroxide, or organic bases such as the amines or the Al-

Educated Theoretical selectivity Time Hydro Hydroperoxide peroxide lot (Vo) (Hours) (G) (G) 100 1 56 56 100 2 100 100 90 3 144 160 77 4th 198 258 73.5 5 270 368 72.5 6th 346 478 71 7th 420 590 68.5 8th 465 680 66 9 490 740 64 10 500 780 62 11 495 800 60 12th 490 820

The results obtained are in the following i§ kylamine (e.g. ethanolamine), which are in aqueous solution Table listed. be applied, or adsorbents, e.g. B. Active

money.

The excellent results obtained by using a base are completely unexpected since ao by no means the formation of olefin alcohols would have been expected, but of aldehydes and ketones or alkali salts of hydroperoxides, as described in "Angewandte Chemie", Vol. 69, p. 318 (1957) for alkyl aromatic hydroperoxides is indicated. The use of these bases is another characteristic Feature, although it is not mandatory for the present procedure.

Of the above catalysts, because of their cheapness, aqueous 3Q solutions of sodium hydroxide solution or potassium hydroxide solution of varying concentrations, e.g. B. from 0.05 to 2n. It is advisable not to exceed a concentration of 2n if the formation of residues is to be avoided which would reduce the yield of alcohol which is separated by distillation and unsaturated in the results obtained with cyclohexene. The catalytic Bedaß it is essential to keep the degree of conversion low, preferably at temperatures between, the cyclohexene peroxide with an appearance of 0 and 1O ⁰ C, so as largely as shown yield is obtained and the possible formation of By-products are avoided by separation problems that result from the thermal decomposition of the hydroperoxides to the presence of secondary products. avoid. Thus, for example, hydroperoxide solutions with concentrations of 10 to 50% appear in measured, it is possible to add the treated olefin when the reactants are gradually poured in, based on the volume in normal aqueous potassium hydroxide solution a volume of the reaction vessel in such a way that from two fifths to two times the hydropoints that there is still a sufficient constant peroxide solution which, taking into account the exo-

The concentration of hydroperoxides in the re - "- ■■ - - -

action vessel is present. Regardless of how it was obtained, the solution of the hydroperoxides in the can treated olefin, which is withdrawn from the reaction mixture, if necessary, in vacuo at ordinary Temperature are concentrated, with the separated olefin returned to the reaction vessel can be.

The solution or the concentrate of the Hydroper 55 separates, to remove traces of sodium hydroxide with oxyds, the water is then washed neutral in the course of the second stage, subjected to the action of a decomposition catalyst over sodium sulfate or in a known manner to the action of a reducing agent. To the
usable reducing agents, which are preferably
at a temperature between 30 and 80 ° C include potassium and
Sodium iodide, sodium and potassium sulfite, sodium
and potassium sulfhydrate, iron thioeyanate and titanium sulfate, which are preferably used in a mixture, a mixture of the stannous and titanochlorides, the

thermity of the reaction is maintained at a temperature of about 10 ° C, within about one Reduced hour without stirring or shaking the mixture.

The alcohol formed, which is insoluble in the aqueous basic solution and has a double bond in the α position accumulates in the hydrocarbon phase during the catalytic process. She will be

Arsenite, the salts of lead, iron, mercury, Copper, manganese, cobalt, and all of them in general

dries and distilled. In this way, the alcohols unsaturated in the α-position are obtained in excellent, Yields coming very close to the theoretical values. The recovered olefin can be returned to the reaction vessel used in carrying out the first process stage will.

The α-unsaturated alcohols obtained by the second process stage are then used in subjected to the third stage of dehydration, the corresponding conjugated diolefins in excellent yields can be obtained.

The dehydration can be carried out in the vapor phase by evaporating the Alcohol with a double bond passes through a fixed bed of a dehydration catalyst. The dehydration catalyst used is, for example, anhydrous metal oxides, such as aluminum oxide, Thorium oxide, chromium oxide, tungsten oxide, clays, kaolin, alum and aluminum and sodium phosphates. The temperature used is

a temperature of 75 ° C into the liquid mass, stirring well until it is reached a concentration of 6% of hydroperoxide in the reaction mixture is maintained. The mixture will then withdrawn at a rate of 65 kg per hour while the olefin feed is adjusted is that the reaction volume remains constant. The resulting solution of the heptenyl peroxides in the Hepten- (3) is then used in a vacuum at ordinary

concentrated between 200 and 375 ° C and in all cases above io temperature until the concentration> 30% the boiling point of the to be dehydrated in, and the concentrate is in a normal, α-position of unsaturated alcohol, since the dehydrated aqueous solution of sodium hydroxide, which on a ization takes place under atmospheric pressure. Temperature of 50 ° C is maintained, poured. the

It should be noted that the mixture used is stirred for one hour, after which time Temperatures are significantly below those that are separated from the hydrogen layer, with them In the process of direct dehydration of water washes to neutral point, via sodium monoolefins sulphate dries to diolefins in the vapor phase and distilled. You win on this are required. Way Heptenus unconverted and get one

The dehydration can also be carried out in the liquid phase mixture of isomeric heptenols with an output With the help of suitable catalysts, a yield of 70%, based on the converted heptene, is carried out. the, z. B. the strong mineral acids and acid anhy- This mixture is heated to 330 ° C and one

drides, such as phosphoric acid and sulfuric acid, subject to dehydration in the vapor phase, in-hydrohalic acids, such as hydrochloric acid, bromine-bromine acid, Hydroiodic acid, which conducts the corresponding oxide. This gives a mixture of hepta salts, such as zinc chloride, acidic potassium or sodium 25 diene (1,3) and heptadiene (2,4) in a yield of sulfates and phosphates, aniline hydrobromide and 86%, with the remainder being completely unconverted Alcohol exists, which is recycled after separation from the diolefin. Since then the The yield of the dehydration stage is 100%, 30 is the total yield of diolefin, based on converted. Monoolefin, at 70%.

other catalysts known for dehydration in the liquid phase, such as iodine or some of the Catalysts mentioned above for the reaction in the vapor phase, such as aluminum oxide or clays.

Even if dehydration in the vapor phase often leads to better yields than that Dehydration in the liquid phase, the latter offers certain advantages, especially because because lower temperatures need to be used. Because of this, it becomes dehydrated in the liquid phase preferred if the alcohol can be dehydrated sufficiently easily, what

Example 2

200 l of dodecene (2) to which 3 to 41 dodecenyl hydroperoxide are added as initiator are introduced into the reaction vessel described in Example 1. Oxygen is passed in a closed circuit into the mixture, which is kept ^{at 100 ° C. and atmospheric pressure}

is especially the case with the tertiary alcohols.

The dehydration in the liquid phase takes place in the 40 until a hydroperoxide concentration is achieved

generally at temperatures at or slightly below 3.4%. Then the reaction mixture

half the boiling point of the Aiko to be treated with continued further introduction of oxygen

hols, but in all cases above the boiling temperature at a rate of 6 kg per minute.

temperature of the diolefin and water (100 ° C), so that the olefin feed is adjusted so that

these two reaction products are distilled off 45 so that the reaction volume remains constant. By

can. When treating in the vapor phase, evaporation in a vacuum to a concentration of

in some cases, when dehydrating the approximately 20% hydroperoxide solution,

lower alcohols, the risk of cracking as described in Example 1, treated, and you

forming products. receives a mixture of dodecenols in one

The dehydration of 98% of the un- 50%, based on the converted olefin,

This mixture is then obtained in the vapor phase at

subjected to fractional distillation to the formed Separate diolefin from the unreacted alcohol, which is recycled. The following examples illustrate the invention.

example 1

A one-capacity reaction vessel is used from 2501, that with a stirrer and in its upper part with an opening for introduction of the olefin to be treated and at its lower part with an opening for the introduction of Oxygen and an opening to withdraw the re-

Dehydrated 350 ° C by passing it through a catalyst bed of 10 kg of aluminum oxide at a rate of 1 kg per minute. A mixture of dodecadiene (2,4) and ¹ dodecadiene (3,5) is obtained in a yield of 80%, based on the dodecenol mixture. The diolefin yield, based on the converted monoolefin, is accordingly about 78.5%.

Example 3

In 2001, 2-methyl-pentene- (2), the 4 to 5 liters, are introduced into the reaction vessel described in Example 1 Contain 2-methylpentenylhydroperoxides, which as

action mixture is provided. One leads 200 1

Hepten- (3), which act 4 to 5 liters of a heptenyl hydroper- 65 initiator. The reaction oxide mixture heated to 60 ° C contained, which is used as an initiator for the remixing then under a partial pressure of oxygen action works. Oxygen is passed in a shaken or stirred under 1 atm. The total pressure Atmospheric pressure closed circuit and below is then about 1.5 at. The reaction continues

leads until the hydroperoxide concentration is 12%. Then the reaction mixture is at a rate subtracted from 48 kg per hour, the olefin feed being regulated so that the volume of the reaction mixture remains constant. The hydroperoxide solution in the olefin is then in vacuo evaporated to a concentration of about 40%. Then it is, as described in example 1, treated, but instead of sodium sulfite 50% potassium sulfite is used. After separation by distillation, a mixture of 2-methyl pentenols is obtained in one yield of 85% of theory, based on the converted olefin. This mixture is then in the liquid Phase in the presence of phosphoric acid as a catalyst at a temperature of 140 to 150 ° C dehydrated.

By distilling the product obtained, a mixture of 2-methyl-pentadiene- (2,4) and ¹ 2-M & -thyl-pentadiene- (1,3) is obtained in a yield of 78%, based on the converted 2-methyl- pentene (2), separated.

Example 4

200 liters of 4-methyl-hepten- (3), the 5 to 61, are introduced into the reaction vessel described in Example 1 contain a 4-methyl-heptenyl-hydroperoxide mixture, that acts as an initiator. Oxygen is passed into the closed circuit at one temperature of 75 ° C and kept under atmospheric pressure until the hydroperoxide concentration is 7% amounts to. The reaction mixture is then drawn in at one rate with continued introduction of oxygen from 150 kg per hour, adjusting the olefin feed so that the volume of the Reaction mixture remains constant. The withdrawn hydroperoxide solution is then evaporated in the Vacuum brought to a concentration of about 30% and, as described in example 1, treated further, however, the sodium sulfite solution by a potassium iodide solution containing 0.5 to 1 kg per 1 replaced. This gives a mixture of 4-methyl-heptenols with a yield of 82%, based on the olefin converted. This mixture is then 'in the liquid phase in the presence of Phosphoric acid, which acts as a catalyst, is dehydrated at a temperature of around -150 ° C. You get a mixture of 4-methyl-heptadiene- (2,4) and 4-methyl-heptadiene- (3,5) in a yield of 85%, based on the 4-methyl-'heptenol mixture.

Example 5

In the reaction vessel described in Example 1, 3-methyl-butene (1) is introduced in 2001, the 2 to 3 liters Contain 3-methyl-butenyl-hydroperoxide as initiator. The mixture, heated to a temperature of 80 ° C., is then subjected to partial pressure of oxygen stirred by 1 at. The total pressure is then about

7.5 at. The reaction is continued until a hydroperoxide concentration of 5 ° / »is available. The reaction mixture is at a rate of

6.6 kg per minute deducted, the olefin feed being adjusted so that the volume of the reaction mixture remains constant. Then the solution of the Hydroperoxide in the olefin evaporated in vacuo until the concentration is about 10%. she is, as described in Example 1, treated further, but using the aqueous sodium sulfite solution replaced by an aqueous sodium iodide solution with a content of 2 kg per liter.

After separation by distillation, the 3-methyl-butenols are obtained in a yield of 85% of theory, based on the olefin. They are then dehydrated in the liquid phase at a temperature of about 120 ^° C. by passing them through a catalyst bed at a rate of 1.51 per minute, which consists of 20 to 25 kg of pumice stone and 4 to 5 kg of sodium bisulfate ( NaHSO ₄ ). The isoprene is separated off from the dehydration product by distillation and is obtained in a yield of 90%, based on the converted alcohol, the remainder mainly consisting of polymers.

The 3-methyl-butenols can also be dehydrated in such a way that they are by a 10% aqueous oxalic acid solution, which is kept at 60 ° C, conducts.

Example 6

In 2001 cyclohexene is introduced into the reaction vessel described in Example 1, the 5 to 61 cyclohexenyl (3) hydroperoxide contains as initiator. Air is fed into the one in a closed circuit Temperature of about 55 ° C and under atmospheric pressure maintained mixture until the hydroperoxide concentration is 16%. With continued initiation the reaction mixture is then withdrawn from air at a rate of 18 kg per hour, the olefin feed being regulated in such a way that the volume of the reaction mixture remains constant. The hydroperoxide solution is then gradually poured into aqueous n-sodium hydroxide solution, which is maintained at a temperature of 40 ° C. during the entire reaction time, which is approximately 80 minutes. After pouring and separating the The hydrocarbon phase is washed to remove traces of the sodium hydroxide solution to neutrality with water and dry over sodium sulfate. The distillation of the solution obtained provides the cyclohexene (1) -ol- (3) in a yield of 97%, based on the converted olefin. That Product is dehydrated in the vapor phase by blowing it at a speed of 300 ecm per minute at a temperature of 270 ° C through a catalyst bed of 3 kg at 350 ° C activated aluminum oxide directs. This gives a mixture from which the cyclohexadiene (1,3) is separated off by distillation will. The yield is 85%, based on the converted cyclohexen- (1) -ol- (3).

Example 7

200 liters of 1-methylcyclohexene (2) are introduced into the reaction vessel described in Example 1 to 6 11-methyl-cyclohexenyl-hydroperoxide as initiator contains. Air is passed in a closed circuit into the room which is kept at 55.degree. C. under atmospheric pressure Mix in until a constant concentration of hydroperoxide of 17% in the reaction vessel is present. Then, with continued bubbling of air, the reaction mixture increases at one rate subtracted from 42 kg per hour, the olefin feed being adjusted so that the volume of the reaction mixture remains constant. The drawn off solution is by evaporation in vacuo to a Concentration of 60% brought and the concentrate

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gradually in aqueous 0.5 N potassium hydroxide solution poured, which is kept at a temperature of 10 ° C during the entire reaction time. To The reaction has ended in about 20 minutes, and the solution obtained is, as described in Example 6, further treated. This gives a mixture of 1-methyl-cyclohexenols in a yield of 99%, based on the converted olefin. This mixture is dehydrated in the vapor phase by making it at a rate of 200 ecm per minute at a temperature of 280 ° C through a catalyst bed derives from 6 kg of alum. After the mixture has been distilled, the methylcyclohexadiene is obtained in a yield of 96%, based on the methylcyclohexene.

In most of the examples given above, the first stage of the autoxidation of the olefins takes place Atmospheric pressure under simple and economical conditions. It should be noted that Such a treatment without the use of solvents is only possible in the case of olefins which have a Have boiling point of over 65 ° C, with a temperature of about in the reaction mixture 50 ° C.

In general, in the case of oxidation under atmospheric pressure, it is advantageous to use a reaction temperature apply, which is at least 15 ° C below the temperature at which the treated olefin boils. This range of 15 ° C was determined experimentally and applies to the entire range of reaction temperatures, which are preferably between 50 and 125 ° C. when carrying out the process according to the invention.

Although the preceding examples all relate to the treatment of well-defined olefins in order to to be able to specify more precisely by the essential characteristics of the method according to the invention, so It goes without saying that the method according to the invention also applies to the treatment without modification of olefin mixtures can be used, in which case a mixture of conjugated diolefins is formed, optionally by any known separation process, e.g. B. fractional distillation, from each other can be separated.

In some cases, however, depending on the intended use, the mixtures of the conjugated diolefins can be used directly without a separation of the different diolefins of the mixture is necessary.

Claims (5)

PATENT CLAIMS: 1. A process for the preparation of conjugated diolefins, in which a stream of oxygen or an oxygen-containing gas at a temperature below 150 ° C in a liquid, a carbon chain of at least 4 carbon atoms containing olefin of the aliphatic or cycloaliphatic series to convert the same into its hydroperoxide conducts, the hydroperoxide formed is converted into the olefin alcohol by treatment with a decomposition agent or reducing agent at a temperature below 150 ° C., whereupon a dehydration catalyst is allowed to act on the latter after heating to a temperature between 100 and 375 ° C., and the diolefin formed is isolated characterized in that the degree of conversion of the olefin during the oxidation is kept between 2 and 20% and that the olefin hydroperoxide dissolved in the unconverted olefin is converted into the olefin alcohol. 2. The method according to claim 1, characterized in that the decomposition agent is aqueous Solutions of inorganic or organic bases used. 3. The method according to claim 2, characterized in that that the inorganic base, sodium hydroxide, potassium hydroxide, barium hydroxide or calcium hydroxide is used. 4. The method according to claim 2, characterized in that one is used as the organic base Amine used. 5. Process according to claims 1 to 4, characterized in that the concentration of the olefin in the reaction mixture keeps exactly constant by continuously adding olefin admitting exactly the same speed with which it is implemented and by having an equal Amount of reaction mixture removed. Considered publications:
German Patent No. 943 705;
British Patent No. 577,364;
Angewandte Chemie, 69 (1957), p. 313 fi. © 209 679/313 10.62