EP0000534A1 - Process for the preparation of vinyl oxiranes - Google Patents

Abstract

1. Process for the preparation of vinyloxirane and substituted vinyloxiranes from polyenes and percarboxylic acids, characterised in that a polyene of the formula see diagramm : EP0000534,P9,F5 wherein R1 , R2 , R3 , R4 , R5 and R6 independently of one another denote hydrogen, C1 - to C4 -alkyl, vinyl, C3 - to C7 -cycloalkyl or phenyl, and wherein R1 and R3 , R1 and R4 or R1 and R5 can form a carbocyclic ring with up to 12 carbon atoms, is reacted with a solution of a percarboxylic acid containing 3 to 4 carbon atoms in an aromatic hydrocarbon with 6 to 12 carbon atoms or in a chlorinated hydrocarbon containing 1 to 8 carbon atoms, which solution contains up to 5% by weight of water, up to 2% by weight of hydrogen peroxide and less than 50 ppm of mineral acid, at a molar ratio of polyene to percarboxylic acid of 1.5:1 to 5:1 and at a temperature of -20 degrees C to +100 degrees C.

Description

The present invention relates to a process for the preparation of vinyloxiranes from polyenes and percarboxylic acids.

Vinyloxiranes are particularly important as monomers because of their bifunctional structure. They are therefore used both in the field of paints and plastics and as organic intermediates. To a large extent, no technical use of vinyloxiranes has taken place since no satisfactory technical process has yet been available for their production.

Many methods for converting olefins to oxiranes are known and attempts have been made to use these methods to produce vinyl oxiranes. For example, US Pat. No. 3,232,957 proposes converting olefins with molecular oxygen in the liquid phase into the epoxides. In column 10, line 15, example 8 of the patent mentioned, the reaction of butadiene with oxygen at 150 ° C. in dicyclopropyl ketone as a solvent is described. However, the vinyl oxirane yield achieved was low; it was only 25%. The use of acetophenone instead of dicyclopropyl ketone as solvent also only yielded a slightly higher yield of vinyl oxirane; it was only 28% (U.S. Patent 3,232,957, column 12, line 15).

The halohydrin method, which has long been known for the production of oxiranes from olefins, has also been used for the production of vinyl oxiranes. For example, the published Japanese patent application 23 545/64 describes the preparation of isoprene oxide from isoprene monochlorohydrin and alkali metal hydroxide. However, this method has the disadvantage of the formation of undesired chlorinated by-products and environmentally harmful salt waste (Ullmanns Encyklopadie d. Techn. Chemie, Vol. 10, p. 565, left column, line ff .; DAS 1 543 174, column 2, line 15 ff. ).

Another method for producing epoxy compounds is based on the reaction of olefins with hydrogen peroxide in the presence of catalysts. The use of this method for the production of vinyloxiranes from polyenes and hydrogen peroxide is described in DAS 2 012 049, p. 15, line 7, example 18, in particular Table I (continued). It reports on the reaction of butadiene with 70% hydrogen peroxide in the presence of trimethyltin hydroxide and the molybdenum salt of acetylacetone as a catalyst. Ethanol was used as the solvent. But even after stirring for 20 hours at 40 ° C., vinyloxirane was only obtained in a yield of 21.7%, based on the hydrogen peroxide used.

Another principle of synthesis is based on the reaction of olefins with organic hydroperoxides with the aid of catalysts. The use of this synthetic principle for the production of vinyloxiranes from polyenes and tert-butyl hydroperoxide or cumene hydroperoxide in the presence of molybdenum hexacarbonyl as a catalyst is described by MN Sheng and JGZajacek (J.Org. Chem. 35, No. 6, (1970) S. 1840, Table I; USA-PS 3 538 "24). Although yields of 84-90% are obtained for the conversion of butadiene, isoprene and piperylene into the monoepoxides, this synthesis principle has the decisive disadvantage that the organic hydroperoxide ROOH, where R is a low molecular weight organic The residue, such as tert-butyl or cumyl, is converted into the corresponding alcohol ROH during the reaction according to the following equation:

Thus it falls of the hydroperoxide used (ROCH) corresponding alcohol as co ^p pelprodukt to what a function of the economics of this process of the usability of this alcohol (ROH) entails. If this alcohol cannot be used, it must be converted back into the corresponding hydroperoxide (ROOH) over several process steps.

Another method for the production of vinyloxirane from butadiene is described in DAS 1 593 306 on page 8 in Example 3. Here butadiene is reacted with tri- (cyclohexylperoxy-) borane at a pressure of 20 bar and a temperature of 100 ° C. Working up the reaction mixture by distillation gave a fraction boiling between 70 ° C. and 126 ° C. which contained vinyloxirane in an amount which corresponded to a yield of 81.7%. Obviously there are problems with the separation of the vinyl oxirane from the reaction mixture with this method. The stated yield of vinyloxirane is also unsatisfactory.

Pummerer and Reindel described the reaction of polyenes with percarboxylic acids for the first time in 1933 (R. Pummerer and W. Reindel, Ber. Dtsch. Chem. Ger. 66, pp. 334-339 (1933)). On page 335, line 16 ff., They report on the epoxidation of isoprene with perbenzoic acid in ethyl chloride as a solvent. The only product you get is 2-methyl-2-vinyloxirane in a yield of 30 to 42%. In the reaction of butadiene with perbenzoic acid, they achieve a yield of about 40% for vinyloxirane.

F.C. Frostick et. al. (J.Am. Chem. Soc, 81, 3354, Table IV) cannot be achieved. In the reaction of butadiene with peracetic acid, which was produced by oxidation of acetaldehyde, in ethyl acetate or acetone as solvent, he achieved a yield of vinyl oxirane of 56%.

The use of special procedural measures as proposed in German PS 1 216 506 for carrying out epoxidations also does not produce satisfactory yields. Example 3, column 8, lines 60 ff. Of this patent describes the reaction of butadiene with peracetic acid in ethyl acetate. Vinyloxirane is obtained in 68% yield.

The use of ferroacetic acid, which was also prepared by oxydation of acetaldehyde, in acetic acid as the solvent is described in Japanese Patent I 74 046-284, and the use of perisobutyric acid, which was obtained by oxidation of isobutyraldehyde, in isobutyric acid as the solvent is proposed in Japanese PS I 74 040-202 for the epoxidation of butadiene. The use of carboxylic acid as as a solvent in the production of oxiranes, however, has the disadvantage that many oxiranes react with carboxylic acids with ring opening to give the acylates (D. Swern, "Organic Peroxides", Wiley Interscience, 1971, Vol. 2, p. 376, line 10 ff .), which can lead to considerable losses in yield.

In DAS 1 190 926 the percarboxylic acid is generated "in situ" during the reaction with butadiene. However, the yield achieved here is also unsatisfactory. Column 15, line 5 ff., Describes the reaction of butadiene at 73-76 ° C in ethyl acetate as a solvent with oxygen in the presence of n-butyraldehyde and cobalt naphthenate as a catalyst. The yield of epoxy is given as 55%. 45% of this is accounted for by butadiene monoxide and 10% by butadiene dioxide.

A further possibility for the production of vinyl oxiranes is described in British PS 735 974. In Example 13, column 8, lines 31 ff., The reaction of butadiene with acetaldehyde monoperacetate prepared by oxidation of acetaldehyde in acetone as solvent at 70 ^° C. is described therein. However, vinyloxirane is only obtained in a yield of 33%.

Another synthesis principle for the epoxidation of polyenes is described in US Pat. No. 3,053,856. The reaction of butadiene with hydrogen peroxide is carried out in the presence of acetonitrile, vinyloxirane being obtained as the main product (Example XII). However, in this process it must be accepted that the carboxylic acid amide formed from the nitrile during the reaction is obtained as a by-product, which is either Appropriate use supplied or must be subjected to dehydration in order to be returned to the process.

worin R₁, R₂, R₃, R₄, R₅ und R₆ unabhängig voneinander Wasserstoff, C₁- bis C₄-Alkyl, Vinyl, C₃- bis C₇-Cycloalkyl oder Phenyl bedeuten und worin R₁ mit R₃, R₁ mit R₄, oder R₁ mit R₅ einen carbocyclischen Ring mit bis zu 12 Kohlenstoffatomen bilden können,
mit einer Lösung einer 3 bis 4 Kohlenstoffatome enthaltenden Percarbonsäure in einem aromatischen Kohlenwasserstoff mit 6 bis 12 Kohlenstoffatomen oder in einem chlorierten, 1-8 Kohlenstoffatome enthaltenden Kohlenwasserstoff bei einem Molverhältnis von Polyen zu Percarbonsäure wie 1,1:1 bis 10:1 und bei einer Temperatur von -20°C bis +100°C umsetzt.In contrast, it has now been found that vinyloxirane and substituted vinyloxiranes can be prepared from polyenes and porcarboxylic acids in organic solution in high yields and high purity if a polyene of the formula

wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ independently of one another are hydrogen, C ₁ - to C ₄ -alkyl, vinyl, C ₃ - to C ₇ -cycloalkyl or phenyl and in which R ₁ with R ₃ , R ₁ with R ₄ , or R ₁ with R _{5 can form} a carbocyclic ring with up to 12 carbon atoms,
with a solution of a percarboxylic acid containing 3 to 4 carbon atoms in an aromatic hydrocarbon with 6 to 12 carbon atoms or in a chlorinated hydrocarbon containing 1-8 carbon atoms at a molar ratio of polyene to percarboxylic acid such as 1.1: 1 to 10: 1 and one Temperature from -20 ° C to + 100 ° C implemented.

worin R₇, R₈, R₉ und R₁₀ unabhängig voneinander Wasserstoff, C₁- bis C₄-Alkyl, Vinyl, C₅- bis C₇-Cycloalkyl oder Phenyl bedeuten und worin R₇ mit R₈, R₇ mit R₉ oder R₇ mit R₁₀ einen carbocyclischen Ring mit bis zu 12 Kohlenstoffatomen bilden können.

worin R₁₁, R₁₂ und R₁₃ unabhängig voneinander Wasserstoff, C₁- bis C₄-Alkyl, Vinyl, C₁- bis C₅-Cycloalkyl oder Phenyl bedeuten und n für eine ganze Zahl von 3 bis 6 steht;

worin R₁₄, R₁₅, R₁₆ und R₁₇ unabhängig voneinander Wasserstoff, C₁- bis C₄-Alkyl, Vinyl, C₅- bis C₇-Cycloalkyl oder Phenyl bedeuten und n für eine ganze Zahl von 2 bis 5 steht;

wobei R₁₈, R₁₉, R₂₀ und R₂₁ unabhängig voneinander Wasserstoff, C₁- bis C₄-Alkyl, Vinyl, C₅- bis C₇-Cycloalkyl oder Phenyl bedeuten und n für eine ganze Zahl von 1 bis 4 steht.In the context of the compounds of the formula (I), compounds of the following formula (II-V) are particularly suitable:

wherein R ₇ , R ₈ , R ₉ and R ₁₀ independently of one another are hydrogen, C ₁ - to C ₄ -alkyl, vinyl, C ₅ - to C ₇ -cycloalkyl or phenyl and in which R ₇ with R ₈ , R ₇ with R ₉ or R ₇ with R _{10 can form} a carbocyclic ring with up to 12 carbon atoms.

wherein R ₁₁ , R ₁₂ and R ₁₃ independently of one another are hydrogen, C ₁ to C ₄ alkyl, vinyl, C ₁ to C ₅ cycloalkyl or phenyl and n is an integer from 3 to 6;

wherein R ₁₄ , R ₁₅ , R ₁₆ and R ₁₇ independently of one another are hydrogen, C ₁ to C ₄ alkyl, vinyl, C ₅ to C ₇ cycloalkyl or phenyl and n is an integer from 2 to 5;

wherein R ₁₈ , R ₁₉ , R ₂₀ and R ₂₁ independently of one another are hydrogen, C ₁ - to C ₄ -alkyl, vinyl, C ₅ - to C ₇ -cycloalkyl or phenyl and n is an integer from 1 to 4.

• Butadien, Isopren, Piperylen, Cyclopentadien, Methyl-cyclopentadien, 2,4-Dimethyl-1,3-butadien, 1,3-Dimethyl-1,3-butadien, 2,4-Hexadien, 1,3-Hexadien, 1,3,5-Hexatrien, Dimethyl-cyclopentadien, 2-Methyl-1,3-pentadien, 3-Methyl-1,3-pentadien, 4-Xethyl-1,3-pentadien, 2-Äthyl-1,3-butadien, 1,3-Cyclohexadien, Methylen-2-cyclopenten, Methylen-2-cyclohexen, 3,4-Dimethyl-1,3-pentadien, 2,4-Dimethyl-1,3-pentadien, 2-Methyl-2,4-hexadien, 2-Methyl-1,3-hoxadien, 2-Methyl-1,3,5-hexatrien, 3-Methyl-1,3-hexadien, 4-Mehyl-1,3-hexadien, 3-Methyl-1,3,5-hexatrien, Methyl-1,3-cyclohexadien, 1,3-Cycloheptadien, 1,3,5-Cycloheptatrien, Dimethyl-1,3-cyclohexadien, 1-Vinyl-1-cyclohexen, Methyl-1,3-cycloheptadien, 2,5-Dimethyl-1,3-hexadien, 2,5-Dimethyl-2,4-hexadien, 2,5-Dimethyl-1,3,5-hexatrien, 2-Äthyl-1,3-hexadien, 2-Äthyl-1,3,5-hexatrien, 1,3-Cyclooctadien, Cyclooctatetraen, 2,4-Dimethyl-1,3,5-hexatrien, 2,4-Dimethyl-1,3- hexadien, 5,5-Dimethyl-1,3-hexadien, 5,5-Dimethyl-1,3,5-hexatrien, 1,3,7-Octatrien, 2-Methyl-1,3,7-octatrien, 2-Methyl-1,5,7-octatrien, Methyl-1,3-cyclooctadien, 1-Cyclopentyl-1,3-butadien, 2-Cyclopentyl-1,3-butadien, 1,2,3,4-Tetramethyl-cyclopentadien, 2,6-Dimethyl-1,3,7-octatrien, 3,7-Dimethyl-1,3,7-octatrien, 1-Cyclo- hexyl-1,3-outadien, 2-Cyclohexyl-1,3-butadien, 1-Phenyl-1,3- butacien, 2-Phenyl-1,3-butadien, 1,3,9,11-Dodecatetraen, 1,2,3,4-Tetramethyl-cyclooctatetraen.

The following may be mentioned as polyenes:

• Butadiene, isoprene, piperylene, cyclopentadiene, methyl-cyclopentadiene, 2,4-dimethyl-1,3-butadiene, 1,3-dimethyl-1,3-butadiene, 2,4-hexadiene, 1,3-hexadiene, 1, 3,5-hexatriene, dimethyl-cyclopentadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-xethyl-1,3-pentadiene, 2-ethyl-1,3-butadiene, 1,3-cyclohexadiene, methylene-2-cyclopentene, methylene-2-cyclohexene, 3,4-dimethyl-1,3-pentadiene, 2,4-dimethyl-1,3-pentadiene, 2-methyl-2,4- hexadiene, 2-methyl-1,3-hoxadiene, 2-methyl-1,3,5-hexatriene, 3-methyl-1,3-hexadiene, 4-methyl-1,3-hexadiene, 3-methyl-1, 3,5-hexatriene, methyl-1,3-cyclohexadiene, 1,3-cycloheptadiene, 1,3,5-cycloheptatriene, dimethyl-1,3-cyclohexadiene, 1-vinyl-1-cyclohexene, methyl-1,3- cycloheptadiene, 2,5-dimethyl-1,3-hexadiene, 2,5-dimethyl-2,4-hexadiene, 2,5-dimethyl-1,3,5-hexatriene, 2-ethyl-1,3-hexadiene, 2-ethyl-1,3,5-hexatriene, 1,3-cyclooctadiene, cyclooctatetraene, 2,4-dimethyl-1,3,5-hexatriene, 2,4-dimethyl-1,3-hexadiene, 5.5- Dimethyl-1,3-hexadiene, 5,5-dimethyl-1,3,5-hexatriene, 1,3,7-octatriene, 2- Methyl-1,3,7-octatriene, 2-methyl-1,5,7-octatriene, methyl-1,3-cyclooctadiene, 1-cyclopentyl-1,3-butadiene, 2-cyclopentyl-1,3-butadiene, 1,2,3,4-tetramethyl-cyclopentadiene, 2,6-dimethyl-1,3,7-octatriene, 3,7-dimethyl-1,3,7-octatriene, 1-cyclohexyl-1,3- outadiene, 2-cyclohexyl-1,3-butadiene, 1-phenyl-1,3-butaciene, 2-phenyl-1,3-butadiene, 1,3,9,11-dodecatetraene, 1,2,3,4- Tetramethyl-cyclooctatetraene.

worin R₂₂ und R₂₃ unabhängig voneinander Wasserstoff, Methyl, Äthyl, Vinyl oder Phenyl bedeuten.Polyenes of the formula are particularly suitable for reaction with fercarboxylic acids according to the process of the invention

wherein R ₂₂ and R _{23 are} independently hydrogen, methyl, ethyl, vinyl or phenyl.

• Butadien, Isopren, Piperylen, 1,3-Hexadien, 1,3,5-Hexatrien, 2-Athyl-1,3-butadien, 1,3-Dimethyl-1,3-butadien, 2,4-Hexadien, 1-Phenyl-1,3-butadien, 2-Phenyl-1,3-butadien, 1-Methyl-1,3- hcxadien, 1-Methyl-1,3,5-hexadien, 2-Methyl-1,3-pentadien, 2-Methyl-1,3-hexadien, 2-Methyl-1,3,5-hexatrien, 2-Äthyl-1,3-hexadien, 2-Äthyl-1,3,5-hexatrien, 2-Phenyl-1,3,5-hexatrien, 2-Phenyl-1,3-hexadien, 2-Phenyl-1,3-pentadieng

The following may be mentioned in particular as compounds of the formula VI:

• Butadiene, isoprene, piperylene, 1,3-hexadiene, 1,3,5-hexatriene, 2-ethyl-1,3-butadiene, 1,3-dimethyl-1,3-butadiene, 2,4-hexadiene, 1- Phenyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1-methyl-1,3-hexadiene, 1-methyl-1,3,5-hexadiene, 2-methyl-1,3-pentadiene, 2-methyl-1,3-hexadiene, 2-methyl-1,3,5-hexatriene, 2-ethyl-1,3-hexadiene, 2-ethyl-1,3,5-hexatriene, 2-phenyl-1, 3,5-hexatriene, 2-phenyl-1,3-hexadiene, 2-phenyl-1,3-pentadiene

Butadiene, isoprene, piperylene, cyclopentadiene, 1,3,5-hexatriene and 1,3,7-octatriene are very particularly suitable for reaction with percarboxylic acids by the process according to the invention.

A wide variety of chlorinated hydrocarbons can be used as solvents, such as methylene chloride, chloroform, carbon tetrachloride, 1-chloroethane, 1,2-dichlorocretane, 1,1-dichloroethane, 1,1,2,2-tetrachloroethane, 1-chloropropane, 2-chloropropane , 1,2-dichloropropane, 1,3-dichloropropane 2,3-dichloropropane, 1,2,3-trichloropropane, 1,1,2,3-tetrachloropropane, butyl chloride, 1,2-dichlorobutane, 1,4-dichlorobutane, 2,3-dichlorobutane 1,3-dichlorobutane, 1,2,3,4-tetrachlorobutane, tert-butyl chloride, amyl chloride, 1,2-dichloropentane, 1,5-dichloropentane, 1,2,3,4-tetrachloropentane, Cyclopentyl chloride, 1,2-dichlorocyclopentyl chloride, hexyl chloride, 1,2-dichlorohexane, 1,6-dichlorohexane, 1,2,3,4-tetrachlorohexane, 1,2,5,6-tetrachlorohexane, cyclohexyl chloride, 1,2-dichlorohexane, Chlorobenzene, heptyl chloride, 1,2-dichloroheptane, 1,2, 1,2,3,4-tetrachloroheptane, cycloheptyl chloride, 1,2-dichloroheptane, octyl chloride, 1, 2-dichloroctane, 1,2,3,4-tetrachloroctane , Cyclooctyl chloride or 1,2-dichloroctane, and aromatic hydrocarbons substances such as benzene, nitrobenzene, toluene, ethylbenzene, cumene, diisopropylbenzene, xylene or chlorobenzene.

Preferred solvents are the chlorinated hydrocarbons methylene chloride, chloroform, carbon tetrachloride and 1,2-dichloropropane, the aromatic hydrocarbons benzene, nitrobenzene. Toluene and chlorobenzene.

Of the chlorinated hydrocarbons, 1,2-dichleropropane and of the aromatic hydrocarbons benrol and chlorobenzene are particularly preferred solvents.

Solvent mixtures of chlorinated hydrocarbons and solvent mixtures of aromatic hydrocarbons can also be used. Mixtures of chlorinated and aromatic hydrocarbons can also be used as solvents.

Peracids which can be used according to the invention are perpropionic acid, per-n-butyric acid and perisobutyric acid. Perpropionic acid and perisobutyric acid are preferably used. Perpropionic acid is particularly preferred. The preparation of the mineral acid-free peracids in one of the organic solvents mentioned can e.g. according to the procedure described in DOS 2 262 970.

In general, the process according to the invention is carried out in a temperature range from 20 to 100 ° C. It is preferred to work at 0-60 ° C, particularly preferably at 10-40 ° C. In special cases, the specified temperatures can also be exceeded or fallen short of.

In addition to working under isothermal conditions, ie maintaining a uniform temperature throughout the reaction mixture, the reaction can also be carried out with the formation of a so-called temperature gradient, which generally increases with the progress of the reaction. However, the reaction can also be carried out in such a way that a gradient of falling temperature is formed as the reaction proceeds.

According to the invention, the molar ratio of olefin to peracid is 1.1: 1 to 10: 1. A molar ratio of 1.5: 1 to 5: 1 is preferably used. It is particularly advantageous to use a molar ratio of 2.0 to 3.0 moles of polyene per mole of peracid.

The method according to the invention can be carried out at a wide variety of pressures. Generally one works at normal pressure; however, the method can also be carried out under negative or positive pressure.

The water content of the percarboxylic acid used for the epoxidation should generally be as low as possible. Small amounts of water up to 5% by weight are generally not disturbing. For example, a percarboxylic acid with a water content of up to 1% by weight is suitable. A percarboxylic acid solution which contains less than 0.5% by weight of water is preferably used. A water content of less than 0.1% by weight, e.g. a water content of 0.01-0.1% by weight

The hydrogen peroxide content of the percarboxylic acid used should generally be as low as possible. It can be up to 2% by weight. It is advantageous to work with a content of less than 1% by weight. It is particularly advantageous to carry out the reaction with a percarboxylic acid solution which has a hydrogen peroxide content below 0.3% by weight, for example an H ₂ O ₂ content of 0.01-0.3% by weight.

The mineral acid content of the percarboxylic acid solution to be implemented should be as low as possible. It is advantageous to carry out the reaction with a percarboxylic acid solution which has a mineral acid content below 50 ppm. A mineral acid content is particularly advantageous less than 10 ppm.

The reaction can be carried out batchwise or continuously in the apparatuses customary for reactions of this type, such as stirrer boilers, boiling reactors, tubular reactors, loop reactors or loop reactors.

Glass, stainless steel or enamelled material can be used as materials for carrying out the processes.

Heavy metal ions in the reaction mixture catalyze the decomposition of the percarboxylic acid. Substances are therefore generally added to the percarboxylic acid solution which inactivate the heavy metal ions through complex formation. Known substances of this type are sluconic acid, ethylenediaminetetraacetic acid, sodium silicate, sodium pyrophosphate, sodium hexametaphosphate, disodium dimethyl pyrophosphate or Na ₂ (2-ethylhexyl) ₅ (P ₃ O ₁₀ ) ₂ (DAS 1 056 596, column 4, line 60 ff.).

The polyene can be introduced into the device used for the reaction in various ways. It can be added to the reactor together with the percarboxylic acid solution, or the two components can be fed to the reactor separately. It is also possible to feed the olefin and the percarboxylic acid solution into the reactor unit at various points. When using several ge in cascade _- switched reactors, it may be advantageous to incorporate all of the olefin in the first reactor. However, the olefin can also be divided between the various reactors.

The heat of reaction is dissipated by internal or external coolers. To remove the heat of reaction, the reaction can also be carried out under reflux, i.e. in boiling reactors.

The reaction is expediently carried out with the most complete possible conversion of the percarboxylic acid. In general, more than 95 mol% of the percarboxylic acid is reacted. It is expedient to convert more than 98 mol% of peracid.

When carrying out the reaction between the polyene and the peracid according to the invention, oxirane yields of 90% of theory and above, based on the percarboxylic acid used, can be achieved.

The reaction mixture is worked up in a manner known per se, for example by distillation. In a preferred implementation of the process, an approximately 20% by weight perpropionic acid solution in 1,2-dichloropropane or benzene is added with stirring to the double molar amount of polyene, which is thermostated at 30 ° C. The perpropionic acid solution contains less than 10 ppm mineral acid; it has a water content of less than 0.1% and a hydrogen peroxide content of less than 0.3%. To complex heavy metal ions, about 0.05% by weight of Na ₅ ( _2- ethylhexyl) ₅ (P ₃ O ₁₀ ) _{2 was} added to the perpropionic acid before the reaction. The progress and the end of the reaction are checked by taking samples from the reaction solution at intervals and determining the still present content of percarboxylic acid by titration. After the reaction has ended, the reaction mixture is fractionated.

The following examples illustrate the invention. Unless otherwise stated, all percentages are percentages by weight.

example

Reaction of isoprene with perpropionic acid in 1,2-dichloropropane.

A solution of 235 g (0.5 mol) of perpropionic acid as a 20% solution in 1,2-dichloropropane was added dropwise to 20.15 ° C. to 85.15 g (1.25 mol) of isoprene with stirring at 20 ° C. After the dropping had ended, the mixture was stirred at this temperature for a further 1.5 hours; then the titrimetric analysis showed a peracid conversion of 99%. Gas chromatographic analysis showed that the two isomeric oxiranes 2-methyl-2-vinyl-oxirane and 2- (1-methylethenyl -) - oxirane were formed in a ratio of 4: 1. The overall selectivity of the two oxiranes was 90.5%, based on the perpropionic acid used.

Example 2

Production of vinyl oxirane from butadiene and perpropionic acid.

To 145.8 g (2.7 mol) of butadiene in 730 g of benzene, 450 g (1 mol) of perpropionic acid was added dropwise at 40 ° C. with stirring as a 20% solution in benzene. After the dropping had ended, stirring was continued for a further 2 hours; then the peracid conversion was 99%. The selectivity of the _V inyloxirans formed was, based on the starting peracid, 95% (GC analysis).

Example 3

Continuous production of vinyl oxirane from butadiene and perpropionic acid.

umgesetzt. Die Reaktion warde bei Druck von 2 bar durchgeführt. Butadien wurde gasförmig in den ersten Reaktor eingegeben. Der Überschuß an Butadien, bezogen auf in die Reaktion eingesetzte Perpropionsäure, betrug insgesamt 170 Mol.-%. Die in das Reaktienssystem stündlich eingegebenen Mengen betrugen 482 g Butadien und 1438 g benzolische Perpropionsäure. Der erste Reaktor dieser vierstufigen Kaskade, der ebenso wie die drei nachfolgenden Reaktionsgefäße mit einer Rührvorrichtung versehen ist und einen Inhalt von 1600 ml besitzt, wird bei einer Temperatur von 35°C, der zweite, dritte und vierte Reaktor bei einer Temperatur von jeweils 40°C betrieben. Die eingesetzte Perpropionsäure wird unter diesen Reaktionsbedingungen zu 99,8 % umgesetzt. Hinter dem vierten Reaktor wurde das Reaktionsgemisch, das mit einer Menge von 1920 g pro Stunde anfiel und im Mittel die Zusammensetzung: 16,52 % Butadien, 11,67 % Vinyloxiran, 21,46 % Propionsäure und 50,08 % Benzol sowie 0,13 % Wasser besaß, nach Abkühlen auf 30°C in einem Abschneider auf Normaldruck entspannt, wobei ein geringer Teil des Butadiens (37 g/h) ausgaste und wieder dem Reaktionssystem zugeführt wurde. Das nach dem Entspannen erhaltene Gemisch wurde mit 2 g/h 4-tert.-Butyl-brenzkatechin versetzt und einer ersten Destillationskolonne zugeführt. Dabei wurde das gesamte Vinyloxiran zusammen mit Butadien und einem Teil des Benzols als Destillat erhalten. Dieses Destillat besaß im Mittel eine Zusammensetzung von 32,6 % Butadien, 27,25 % Vinyloxiran, 39,9 % Benzol und geringen Mengen Wasser Es fiel in einer Menge von

22 g pro Stunde an und wurde anschließend in einer zweiten Destillationskolonne vom Butadien abgetrennt. Man erhielt als Destillat 268 g Butadien pro Stunde, das in das Reaktionssystem zurückgeführt wurde.20.71% benzene perpropionic acid was mixed with excess butadiene in a four-stage cascade

implemented. The reaction was carried out at a pressure of 2 bar. Butadiene was introduced into the first reactor in gaseous form. The excess of butadiene, based on the perpropionic acid used in the reaction, totaled 170 mol%. The amounts entered into the reactant system every hour were 482 g butadiene and 1438 g benzene perpropionic acid. The first reactor of this four-stage cascade, which, like the three subsequent reaction vessels, is equipped with a stirrer and has a content of 1600 ml, is at a temperature of 35 ° C., the second, third and fourth reactors at a temperature of 40 ° each C operated. The perpropionic acid used is converted to 99.8% under these reaction conditions. Behind the fourth reactor, the reaction mixture, which was produced at a rate of 1920 g per hour, and on average the composition: 16.52% butadiene, 11.67% vinyl oxirane, 21.46% propionic acid and 50.08% benzene and 13% water had, after cooling to 30 ° C relaxed in a cutter to normal pressure, with a small part of the butadiene (37 g / h) outgassing and was returned to the reaction system. The mixture obtained after the expansion was mixed with 2 g / h of 4-tert-butyl catechol and fed to a first distillation column. The entire vinyloxirane was obtained together with butadiene and part of the benzene as a distillate. This distillate had an average composition of 32.6% butadiene, 27.25% vinyl oxirane, 39.9% benzene and small amounts of water

22 g per hour and was then separated from the butadiene in a second distillation column. The distillate obtained 268 g of butadiene per hour, which was returned to the reaction system.

From the butadiene-free bottom product, 224 g of vinyloxirane in a purity of 99 were obtained as distillate in a third column. The Suryf product of this. Column was combined with the bottom product of the first column and separated in a fourth column. 361 g of benzene were obtained as the distillate per hour. From the bottom product, 415 g / h of propionic acid were obtained as distillate in a fifth column, while 15 g of a mixture of higher-boiling compounds were obtained per hour at the bottom of this column. These higher boiling compounds consisted essentially of the mono- and dipropionates of 3,4-dihydroxy-1-butene. The yield of vinyloxirane, based on the perpropionic acid used in the reaction system, was 96.7%.

Claims (10)

1. A process for the preparation of vinyloxirane and substituted vinyloxiranes on polyenes and percanon trees, characterized in that a polyene of the formula

wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ independently of one another are hydrogen, C ₁ - to C ₄ -alkyl, vinyl, C ₃ - to C ₇ -cycloalkyl or phenyl and in which R ₁ with R ₃ , R ₁ with R4 or R ₁ with R _{5 can form} a carbocyclic ring having up to 12 carbon atoms,
with a solution of a percarboxylic acid containing 3 to 4 carbon atoms in an aromatic hydrocarbon with 6 to 12 carbon atoms or in a chlorinated hydrocarbon containing 1 to 8 carbon atoms with a molar ratio of polyene to percarboxylic acid such as 1.1: 1 to 10: 1 and one Temperature from -20 ° C to + 100 ° C implemented. 2. The method according to claim 1, characterized in that an olefin of the formula as the polyene

wherein R ₇ , R ₈ , R ₉ and R ₁₀ independently of one another are hydrogen, C ₁ - to C ₄ -alkyl, vinyl, C ₅ - big-C ₇ -cycloalkyl or phenyl and in which R ₇ with R ₈ , R ₇ with R ₉ or R ₇ with R _{10 can form} a carbocyclic ring with up to 12 carbon atoms. 3. The method according to claim 1 and 2, characterized in that an olefin of the formula as the polyene

wherein R ₁₁ , R ₁₂ and R ₁₃ independently of one another are hydrogen, C ₁ - to C ₄ -alkyl, vinyl, C ₁ - to C ₅ -cycloalkyl or phenyl and n is an integer from 3 to 6. 4. The method according to claim 1 to 3, characterized in that an olefin of the formula as the polyene

in which R ₁₄ , R ₁₅ , R ₁₆ and R ₁₇ independently of one another are hydrogen, C ₁ -C ₄ -alkyl, vinyl, C ₅ -C ₇ -cycloalkyl or phenyl and n is an integer from 2 to 5, starts. 5. The method according to claim 1 to 4, characterized in that an olefin of the formula as the polyene

wherein R ₁₈ , R ₁₉ , R ₂₀ and R ₂₁ independently of one another are hydrogen, C ₁ - to C ₄ -alkyl, vinyl, C ₃ - to C ₇ -cycloalkyl, or phenyl and n is an integer from 1 to 4 , begins. 6. The method according to claim 5, characterized in that the polyene is an olefin of the formula

wherein R ₂₂ and R ₂₃ independently of one another are hydrogen, methyl, ethyl, vinyl or phenyl. 7. The method according to claim 1 to 6, characterized in that the polyene used is butadiene, isoprene, piperylene, cyclopentadiene, 1,3,5-hexatriene or 1,3,7-octatriene. 8. The method according to claim 1 to 7, characterized in that perpropionic acid or perisobutyric acid is used as the percarboxylic acid. 9. The method according to claim 1 to 8, characterized in that the solvent used is benzene, chlorobenzene or 1,2-dichloropropane. 10.The method according to claim 1 to 9, characterized in that one carries out the reaction at a molar ratio of olefin to peracid such as 1.5 to 3: 1.