EP0000535B1 - Process for the preparation of vinyl oxiranes substituted by halogen - Google Patents

Description

The present invention relates to a process for the preparation of halogen-substituted oxiranes from halogen-substituted polyenes and percarboxylic acids and to new 2-chloro-2-vinyl and 2-chloro-3-vinyl-oxiranes.

Due to their bifunctional structure, vinyl oxiranes substituted on the oxirane ring or on the vinyl group by halogen are particularly important as monomers. They can therefore be used in the field of paints and plastics, organic intermediates and in crop protection, which is particularly important for the new compounds with 2-chloro-2-vinyl-oxirane and 2-chloro-3-vinyl oxirane structure is of interest.

Various proposals have already been made for the preparation of (1-haloethenyl) oxirane. In 1939, Petrov reported on the production of (1-chloroethenyl) oxirane by reacting chloroprene with hypobromous acid and then dehydrobrominating it with potassium hydroxide. (AA Petrov, J. Gen. Chem. 9, 2232-43 (1939))

In 1957, two synthetic patents (US Pat. No. 2,907,774 and British Pat. No. 864882) published a synthetic route in which (1-chloroethenyl) oxirane was synthesized by dehydrochlorination of (1,2-dichloroethyl) oxirane with alkyl hydroxide has been:

These methods can be used to synthesize (1-haloethenyl) oxiranes; However, their applicability for the production of vinyl oxiranes halogen-substituted on the oxirane ring has not yet been reported.

Furthermore, the French patent application with publication no. 2,300,085 and the literature reference J. Org. Chem. 41, No. 9, 1648 (1976) of interest.

The French patent application relates to the reaction of ethylene, propylene, chlorine- or hydroxy-substituted propylene, butene, pentene and higher alkenes with percarboxylic acid to form oxiranes. No information is given on the quality of the percarboxylic acid used. The only halogen-containing feed described is allyl chloride. In contrast to the compounds which can be used according to the invention, this contains halogen on a saturated carbon atom. From D. Swem, Organic Peroxides, vol. 11, page 490 it is known that epoxides which contain a chlorine atom on the epoxy ring rearrange extremely easily into α-chloro ketones and in many cases that epoxide cannot be isolated. It was therefore not obvious to consider the reaction of halogen-substituted polyenes with percarboxylic acids in order to produce halogen-substituted vinyloxiranes in good yields or to transfer the process known from the French patent application to halogen-substituted polyenes. Methodicum Chimicum, Georg Thieme Verlag, Stuttgart, Volume 5, pages 167/168 (1975) furthermore shows that halogen as a substituent makes epoxidation to a great extent difficult and favors subsequent reactions. With vinyl halides in particular, the primary products (epoxides) are often unstable and rearrangements in carbonyl compounds and polymerizations are frequently observed. It is also surprising with regard to this literary position that according to the invention it is possible to epoxidize compounds which contain the structural element "vinyl halide" in good yields.

According to the literature from J. Org. Chem., It is assumed that 4-chloro-3,4-epoxy-3-methyl-1-butene could occur as an intermediate in a reaction. One way of establishing and isolating this connection is not described.

worin

• R₁ und R₆ unabhängig voneinander Wasserstoff, C₁- bis C₄-Alkyl, Vinyl oder Phenyl bedeuten,
• R₂, R₃, R₄ und R₅ unabhängig voneinander für Wasserstoff, C₁- bis C₄-Alkyl, Vinyl, C₃- bis C₇-Cycloalkyl, Phenyl, Fluor, Chlor oder Brom stehen und wobei mindestens einer der Reste R₂ bis R₅ Fluor, Chlor oder Brom bedeutet und wobei R₁ mit R₂ oder R₁ mit R₃ oder R, mit R₄ oder R, mit R₅ oder R₃ mit R₄ einen carbocyclischen Ring bilden können, mit einer Lösung einer Percarbonsäure in einem organischen Lösungsmittel bei einem Molverhältnis von halogensubstituiertem Polyen zu Percarbonsäure von 1,0:1,0 bis 10, oder von 1,0 bis 10:1,0 und bei einer Temperatur von -20°C bis + 100°C umsetzt, wobei die Percarbonsäure bis zu 5 Gew.-% Wasser, bis zu 2 Gew.% Wasserstoffperoxid und die Percarbonsäurelösung weniger als 50 ppm Mineralsäure enthält. i

In contrast, it has now been found that halogen-substituted vinyl oxiranes can be prepared from halogen-substituted polyenes and percarboxylic acids in organic solution on the oxirane ring and / or on the vinyl group if a halogen-substituted polyene of the formula

wherein

• R ₁ and R ₆ independently of one another are hydrogen, C ₁ -C ₄ -alkyl, vinyl or phenyl,
• R ₂ , R ₃ , R ₄ and R ₅ independently of one another represent hydrogen, C ₁ - to C ₄ -alkyl, vinyl, C ₃ - to C ₇ -cycloalkyl, phenyl, fluorine, chlorine or bromine and at least one of the radicals R ₂ to R _{5 is} fluorine, chlorine or bromine and where R ₁ with R ₂ or R ₁ with R ₃ or R, with R ₄ or R, with R ₅ or R ₃ with R ₄ can form a carbocyclic ring, with a Solution of a percarboxylic acid in an organic solvent at a molar ratio of halogen-substituted polyene to percarboxylic acid from 1.0: 1.0 to 10, or from 1.0 to 10: 1.0 and at a temperature from -20 ° C to + 100 ° C reacts, the percarboxylic acid containing up to 5% by weight of water, up to 2% by weight of hydrogen peroxide and the percarboxylic acid solution containing less than 50 ppm of mineral acid. i

worin

• R_7' R₈, R₉ und R₁₀ unabhängig voneinander Wasserstoff, C₁- bis C_4-Alkyl, Vinyl, C₅- bis C_7-Cycloalkyl, Phenyl, Fluor, Chlor oder Brom bedeuten, wobei mindestens einer der Reste R₇ bis R₁₀, Fluor, Chlor oder Brom darstellt und worin R₇ mit R₈ oder R₈ mit R₉ oder R₉ mit R₁₀ oder R₈ mit R₉ einen carbocyclischen Ring bilden können;
  
• worin R₁₁, _R12 und R₁₃ unabhängig voneinander für Wasserstoff, C₁- bis C₄-Alkyl, Vinyl, C₅- bis C₇-Cycloalkyl, Phenyl, Fluor, Chlor oder Brom stehen, wobei mindestens einer der Reste R₁₁ bis R₁₃ Fluor, Chlor oder Brom bedeutet, und
• R,₄ Wasserstoff, C,- bis C_4-Alkyl, Vinyl oder Phenyl bedeutet,
• n für eine ganze Zahl von 2 bis 10 steht;
  
  worin
• R₁₅, R₁₆ und R₁₇ unabhängig voneinander für Wasserstoff, C₁- bis C₄-Alkyl, Vinyl, C₃- bis C₇-Cycloalkyl, Phenyl, Fluor, Chlor oder Brom stehen, wobei mindestens einer der Reste R₁₅ bis R₁₇ Fluor, Chlor oder Brom bedeutet,
• R₁₈ Wasserstoff, C₁- bis C_4-Alkyl, Vinyl oder Phenyl bedeutet und
• n für eine ganze Zahl von 1 bis 9 steht;

wobei

• R₁₉, R₂₀, R₂₁ unabhängig voneinander Wasserstoff, C,- bis C₄-Alkyl, Vinyl, Phenyl, C₅- bis C₇-Cycloalkyl, Fluor, Chlor oder Brom bedeuten, wobei mindestens einer der Reste R₁₉ bis R₂₂ für Fluor, Chlor oder Brom steht.
• Besonders geeignet zur Umsetzung mit Percarbonsäuren gemäß dem erfindungsgemäßen Verfahren sind Polyene der Formel

worin

• R₂₃, R₂₄, R₂, und R₂₆ unabhängig voneinander Wasserstoff, C,- bis C_4-Alkyl, Vinyl oder Chlor bedeuten, wobei mindestens einer der Reste R₂₃ bis R₂₆ für Chlor steht.

In the context of the compounds of the formula (I), compounds of the following formulas (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, phenyl, fluorine, chlorine or bromine, at least one of the radicals R ₇ to R _{10 represents} fluorine, chlorine or bromine and wherein R ₇ with R ₈ or R ₈ with R ₉ or R ₉ with R ₁₀ or R ₈ with R ₉ can form a carbocyclic ring;
  
• wherein R ₁₁ , _R12 and R ₁₃ independently represent hydrogen, C ₁ - to C ₄ -alkyl, vinyl, C ₅ - to C ₇ -cycloalkyl, phenyl, fluorine, chlorine or bromine, at least one of the radicals R ₁₁ to R ₁₃ denotes fluorine, chlorine or bromine, and
• R _{4 is} hydrogen, C ₁ -C ₄ -alkyl, vinyl or phenyl,
• n represents an integer from 2 to 10;
  
  wherein
• R ₁₅ , R ₁₆ and R ₁₇ independently of one another are hydrogen, C ₁ -C ₄ -alkyl, vinyl, C ₃ -C ₇ -cycloalkyl, phenyl, fluorine, chlorine or bromine, at least one of the radicals R ₁₅ to R ₁₇ denotes fluorine, chlorine or bromine,
• R _{18 is} hydrogen, C ₁ - to C ₄ -alkyl, vinyl or phenyl and
• n represents an integer from 1 to 9;

in which

• R ₁₉ , R ₂₀ , R ₂₁ independently of one another denote hydrogen, C 1 -C ₄ -alkyl, vinyl, phenyl, C ₅ -C ₇ cycloalkyl, fluorine, chlorine or bromine, at least one of the radicals R ₁₉ to R _{22 represents} fluorine, chlorine or bromine.
• Polyenes of the formula are particularly suitable for reaction with percarboxylic acids according to the process of the invention

wherein

• R ₂₃ , R ₂₄ , R ₂ and R ₂₆ independently of one another are hydrogen, C _{1 -C 4} -alkyl, vinyl or chlorine, at least one of the radicals R ₂₃ to R _{26 being} chlorine.

1,3-dichlorobutadiene, 2,3-dichlorobutadiene, 1-chlorobutadiene and 2-chlorobutadiene are very particularly suitable for reaction with percarboxylic acids by the process according to the invention.

The various hydrocarbons can be used as organic solvents, for example aliphatic and cycloaliphatic hydrocarbons such as hexane, heptane, octane, 2-ethylhexane, decane, dodecane, cyclohexane, methylcyclopentane, petroleum ether; aromatic hydrocarbons such as benzene, nitrobenzene, toluene, ethylbenzene, cumene, diisopropylbenzene, xylene, chlorobenzene; oxygen-containing hydrocarbons such as diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, dioxane, pyran, acetone, Methyläthyliketon, ethyl acetate, methyl acetate, propyl acetate, butyl acetate, methyl propionate, propionic acid, ethyl ester, propyl propionate, methyl butyrate, Buttersäureäthylester, Buttersäurepropylester, butyrate, and chlorinated hydrocarbons such as methylene chloride, chloroform, Carbon tetrachloride, 1-chloroethane, 1,2-dichloroethane, 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, 1,2,3,4-tetrachloroheptane, Cycloheptyl chloride, 1,2-dichloroheptane, octyl chloride, 1,2-dichloroctane, 1,2,3,4-tetrachloroctane, cyclooctyl chloride, and 1,2-dichloroctane.

Preferred solvents are the chlorinated hydrocarbons methyl chloride, chloroform, carbon tetrachloride and 1,2-dichloropropane, the aromatic hydrocarbons benzene, nitrobenzene, toluene and chlorobenzene, the hydrocarbons 2-ethyl-hexane, cyclohexane, methyl-cyclopentane and the oxygen-containing hydrocarbons Acetone, tetrahydrofuran, ethyl propionate.

Particularly preferred solvents are 1,2-dichloropropane and carbon tetrachloride from the chlorinated hydrocarbons, benzene and chlorobenzene from the aromatic hydrocarbons, cyclohexane from the hydrocarbons and ethyl propionate from the oxygen-containing hydrocarbons.

Solvent mixtures of the various organic solvents specified above can also be used.

Peracids which can be used according to the invention are perpropionic acid, perbutyric 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.

The process according to the invention is carried out in a temperature range of -20-100 ° 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, i.e. Maintaining a uniform temperature in the entire 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 halogen-substituted polyene to percarboxylic acid is 1.0: 1.0 to 10 or 1.0 to 10: 1.0. A molar ratio of ofefin to percarboxylic acid of 1.0: 1.0 to 5 or 1.0 to 2: 1.0 can also be used. A molar ratio of 1.0: 1 to 5 is preferably used. It is particularly advantageous to use a molar ratio of 2.0 to 3.0 moles of halogen-substituted 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 process can also be carried out under negative or positive pressure.

The water content of the percarboxylic acid used for the epoxidation is up to 5% by weight. 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. 0.01 to 0.1% by weight.

The hydrogen peroxide content of the percarboxylic acid used is 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%, e.g. 0.01 to 0.3% by weight.

The mineral acid content of the percarboxylic acid solution being implemented is less than 50 ppm. A mineral acid content of less than 10 ppm is particularly advantageous.

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

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 gluconic acid, ethylenediaminetetraacetic acid, sodium silicate, sodium pyrophosphate, sodium hexametaphosphate, disodium dimethyl pyrophosphate or Na ₂ (2-ethylhexyl), (P _l o _ll ) ₂ (DAS 1 056 596, column 4, line 60 ff.).

The halogen-substituted 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 reactors connected in cascade, it may be expedient to introduce all of the olefin into 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 advantageously carried out with the most complete possible conversion of the percarbonic acid. In general, more than 95 mol% of the percarboxylic acid is reacted. It is expedient to convert more than 98 mol% of peracid.

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 benzene is added with stirring to the double molar amount of halogen-substituted polyene which is thermostatted 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 content of percarboxylic acid still present by titration. After the reaction has ended, the reaction mixture is fractionated.

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

example 1

Conversion of chloroprene with perpropionic acid into carbon tetrachloride.

A solution of 225 g (0.5 mol) of perpropionic acid as a 20% strength solution in carbon tetrachloride was added dropwise at 40 ° C. to 88.54 g (1 mol) of chloroprene over 30 minutes while stirring. After the dropping had ended, stirring was continued for a further 4 hours at this temperature, and then the titrimetric analysis showed a peracid conversion of 98%. Gas chromatographic analysis showed that the two isomeric oxiranes 2-chloro-2-vinyl-oxirane and (1-chloroethenyl) oxirane were formed in a ratio of 3: 2. The overall selectivity of the two oxiranes was 83.5%, based on the perpropionic acid converted.

Example 2

Conversion of chloroprene with perpropionic acid in benzene. 88.54 g (1 mol) of chloroprene were, as described in Example 1, reacted with 225 g (0.5 mol) of perpropionic acid as a 20% solution in benzene at 40 ° C.

The peracid conversion was 99%. The two oxiranes were again formed in a ratio of -3: 2 with an overall selectivity of 84.5%.

The reaction mixture was worked up by distillation. First, chloroprene, benzene and the two oxiranes were taken off as top product in a distillation column equipped with a thin-layer evaporator, while propionic acid was obtained at the bottom. The two oxiranes, 2-chloro-2-vinyl-oxirane and (1-chloroethenyl) oxirane, were isolated in a purity of more than 99% by further fractionation under reduced pressure.

Example 3

Reaction of 2,3-dichloro-1,3-butadiene with perpropionic acid in benzene. 123 g (1 mol) of 2,3-dichloro-1,3-butadiene were reacted at 30 ° C. with 225 g (0.5 mol) of perpropionic acid as a 20% solution in benzene as described in Example 1. After a reaction time of three hours, the peracid conversion was 98.7%. GC analysis showed that 2-chloro (1-chloroethenyl) oxirane was formed with a selectivity of 78%.

Example 4

Reaction of 1-chloro-1,3-butadiene with perpropionic acid in benzene. 88.54 g (1 mol) of 1-chloro-1,3-butadiene were reacted at 40 ° C. as described in Example 1 with a solution of 225 g (0.5 mol) of perpropionic acid as a 20% solution in benzene. After 4 hours of reaction, the peracid conversion was 99%. The two oxiranes 2-chloro-3-vinyl-oxirane and (2-chloroethenyl) oxirane were formed with an overall selectivity of 87%.

Example 5

Reaction of 1,4-dichloro-1,3-butadiene with perpropionic acid in 1,2-dichloropropane.

123 g (1 mol) of 1,4-dichloro-1,3-butadiene were reacted at 30 ° C. with 225 g (0.5 mol) of perpropionic acid as a 20% solution in dichloropropane as described in Example 1.

After a reaction time of 4 hours, the peracid conversion was 99%. 2-Chloro-3- (2-chloroethenyl) oxirane was formed with a selectivity of 81%.

Claims (7)

1. Process for the preparation of vinyloxiranes which are halogen-substituted on the oxirane ring and/or on the vinyl group from halogen-substituted polyenes and percarboxylic acids in organic solution, characterised in that a halogen-substituted polyene of the formula

wherein

R¹ and R⁶ independently of one another denote hydrogen, C₁- to C_4-alkyl, vinyl or phenyl and R₂, R₃, R₄ and R₅ independently of one another represent hydrogen, C₁- to C_4-alkyl, vinyl, C₃- to C_7-cycloalkyl, phenyl, fluorine, chlorine or bromine, at least one of the radicals R₂ to R₅ denoting fluorine, chlorine or bromine,
and wherein

R₁ and R₂, or R₁ and R₃, or R, and R₄, or R, and R₅, or R₃ and R₄ can form a carbocyclic ring, is reacted with a solution of a percarboxylic acid in an organic solvent at a molar ratio of halogen-substituted polyene to percarboxylic acid of 1.0:1.0 to 10 or 1.0 to 10:1.0 and at a temperature of -20°C to +100°C, the percarboxylic acid containing up to 5% by weight of water and up to 2% by weight of hydrogen peroxide and the percarboxylic acid solution containing less than 50 ppm of mineral acid.

2. Process according to Claim 1, characterised in that a polyene of the formula

wherein

R₁₁, R₁₂ and R₁₃ independently of one another represent hydrogen, C₁- to C_4-alkyl, vinyl, C₅- to C₇ cycloalkyl, phenyl, fluorine, chlorine or bromine, at least one of the radicals R₁₁ to R₁₃ denoting fluorine, chlorine or bromine, R₁₄ denotes hydrogen, C₁- to C_4-alkyl, vinyl or phenyl and

n represents an integer from 2 to 10,

is employed as the halogen-substituted polyene.

3. Process according to Claim 1 and 2, characterised in that a polyene of the formula

wherein

R_15' R₁₆ and R₁₇ independently of one another represent hydrogen, C₁- to C₄-alkyl, vinyl, C₃- to C₇- cycloalkyl, phenyl, fluorine, chlorine or bromine, at least one of the radicals R₁₅ to R₁₇ denoting fluorine, chlorine or bromine,

R₁₈ denotes hydrogen, C,- to C₄-alkyl, vinyl or phenyl and

n represents an integer from 1 to 9,

is employed as the halogen-substituted polyene.

4. Process according to Claim 1 to 3, characterised in that a polyene of the formula

wherein

R₁₉, R₂₀, R₂₁ and R₂₂ independently of one another denote hydrogen, C₁- to C₄-alkyl, vinyl, phenyl, C₅- to C₇-cycloalkyl, fluorine, chlorine or bromine, at least one of the radicals R₁₉ to R₂₂ representing fluorine, chlorine or bromine,

is employed as the halogen-substituted polyene.

5. Process according to Claim 1 to 4, characterised in that a polyene of the formula

wherein

R₂₃, R₂₄, R₂₅ and R₂₆ independently of one another denote hydrogen, C₁- to C₄-alkyl, vinyl or chlorine, at least one of the radicals R₂₃ to R₂₆ representing chlorine,

is employed as the halogen-substituted polyene.

6. Process according to Claim 1 to 5, characterised in that 1,3-dichlorobutadiene, 2,3-dichlorobutadiene, 1-chlorobutadiene or 2-chlorobutadiene is employed as the halogen-substituted polyene.

7. Process according to Claim 1 to 6, characterised in that benzene, chlorobenzene, 1,2-dichloropropane, carbon tetrachloride, propionic acid ethyl ester or cyclohexane is employed as the solvent.