Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D301/00—Preparation of oxiranes
  • C07D301/02—Synthesis of the oxirane ring
  • C07D301/03—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds
  • C07D301/14—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with organic peracids, or salts, anhydrides or esters thereof
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D303/00—Compounds containing three-membered rings having one oxygen atom as the only ring hetero atom
  • C07D303/02—Compounds containing oxirane rings
  • C07D303/08—Compounds containing oxirane rings with hydrocarbon radicals, substituted by halogen atoms, nitro radicals or nitroso radicals

Definitions

• the present invention relates to an improved process for the preparation of haloalkyl-substituted oxiranes from haloalkyl-substituted olefins and percarboxylic acids.
• Haloalkyl-substituted oxiranes are used in the field of paints and plastics and as organic intermediates.
• Haloalkyl-substituted olefins can therefore not be done without percarboxylic acids further epoxidize.
• high temperatures and long reaction times are required, which give rise to undesired by-products such as dihydroxy and hydroxynyloxy derivatives of the starting products gives.
• the structure and method of preparation of the percarboxylic acid used is of great importance, in particular with regard to the type and implementation of the reaction between a halogen alkyl-substituted olefin and a percarboxylic acid.
• Performic acid can be prepared from hydrogen peroxide and formic acid without an additional catalyst (S. N. Lewis in R. L. Augustin, "Oxidation", Vol. I, p. 217, first paragraph, Marcel Dekker, New York 1969).
• the reaction of ⁇ -chloroalkyl-substituted olefins with this mineral acid-free percarboxylic acid also gave the corresponding epoxide only in low yields.
• performic acid prepared from 90 t strength formic acid and 85% hydrogen peroxide was used for the epoxidation of 3,4-dichlorobutene- (1).
• DAS 1 056 596 a process for the production of aliphatic chlorine epoxides by reacting an allyl chlorohydrocarbon, which has a chlorine atom adjacent to the double bond, with an organic per-compound which is free from inorganic impurities.
• the per compounds used are "pure peracetic acid, perpropionic acid or acetaldehyde monoperacetate in a mixture with acetaldehyde and / or acetone".
• DAS 1 056 596 Epoxidation in accordance with the DAS 1 056 596 process of allyl-chlorine-substituted olefins with acetaldehyde monoperacetate yields the corresponding oxiranes in yields based on the per compound between 17 and 56, depending on the olefin %.
• DAS 1 056 596 columns 5 to 7, lines 35 ff., Examples 1, 3, 4 and 6).
• peracetic acid and perpropionic acid used for this epoxidation process are dissolved in an inert solution organic solvents used.
• typical inert solvents in this process include acetone, ethyl acetate, butyl acetate, and dibutyl ether (U.S. Pat. No. 3,150,154, column 3, cells 1-3).
• Allyl chlorohydrocarbons can be epoxidized with the peracids produced according to the process of DAS 1 056 596; however, the yields of oxiranes are low; the peracid conversion is incomplete. In the examples given, it is only about 90 and the purity of the isolated oxiranes is insufficient for industrial use.
• the DAS 1 056 596 in Example 5, column 7, lines 5 ff. Describes the epoxidation of 3-chloro-1-butene with a solution of peracetic acid in acetone. The peracid conversion is 91% after a reaction time of ten hours. The oxirane is isolated with a purity of 90.5% in a 68% yield.
• 1,4-dichloro-2-butene, 1,4-dibromo-2-butene and 3,4-dichloro-1-butene are very particularly suitable for reaction with percarboxylic acids by the process according to the invention.
• aromatic hydrocarbons having 6 to 12 carbon atoms can be used as solvents, which can also be substituted.
• solvents include benzene, nitrobenzene, toluene, xylene, ethylbenzene, diethylbenzene, cumene, diisopropylbenzene and chlorobenzene.
• Aromatic hydrocarbons with 6 to 8 carbon atoms such as benzene, nitrobenzene, chlorobenzene, toluene, xylene and ethyl benzene are particularly suitable.
• Preferred solvents are benzene and toluene. Benzene is a particularly preferred solvent. Mixtures of various aromatic hydrocarbons can also be used.
• Peracidic acid, perbutyric acid and perisobutexic acid can be used according to the invention.
• Perpropionic acid and perisobutyric acid are preferred.
• Perpropionic acid is particularly preferred.
• the preparation of the mineral acid-free peracids in one of the organic solvents mentioned can, for. B. after dea in the DOS 2 262 970 described procedures In general, the process is carried out in practice in a temperature range of 30-100 ° C. It is preferred to work at 60-80 ° C, particularly preferably at 65-75 ° C. In special cases, the specified temperatures can also be fallen below or exceeded.
• 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.
• the reaction can also be carried out in such a way that a gradient of falling temperature is formed as the reaction proceeds.
• the molar ratio of olefin to peracid is 1.1: 1 to 10: 1.
• a molar ratio of 1.25: 1 to 5: 1 is preferably used. It is particularly advantageous to use a molar ratio of 1.5 to 3.0 moles of olefin 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 should generally be as low as possible. Small amounts of water up to 5% by weight are generally not disturbing. For example, a percabonic acid with a water content of up to 2% by weight is suitable. A percarboxylic acid solution which contains less than 1 part by weight of water is preferably used. A water content of less than 0.1% by weight is particularly preferred.
• the hydrogen peroxide content of the percarboxylic acid used should generally be as low as possible. It can be up to 2% by weight. Is advantageous to work at a level of less than 1 G ew .-%. It is particularly advantageous to carry out the reaction with a percarbonate solution which has a hydrogen peroxide content below 0.3%.
• 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 of less than 1C 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.
• 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 gluconic acid, ethylenediaminetetraacetic acid, sodium uriculate, sodium pyrophosphate, sodium hexamethane phosphate, disodium dimethyl pyrophosphate or Na 2 (2-ethylhexyl) 5 (P 3 O 10 ) 2 (DAS 1 056 596, column 4, ropes 60 ff.).
• the haloalkyl-substituted olefin can be introduced into the device used for the reaction in various ways become. 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.
• the reaction can also be carried out under reflux (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.
• the reaction mixture is worked up in a manner known per se, for. B. by distillation. It is particularly advantageous to extract the reaction mixture with water before the work-up by distillation to separate off the carboxylic acid formed during the reaction and corresponding to the percarboxylic acid.
• the extraction can be carried out in the usual extractors, such as mixer-separators, sieve tray extractors, pulsating sieve tray columns, turntable extractors or extraction centrifuges.
• an approximately 20% by weight perpropionic acid solution in benzene is added with stirring to the triple-molar amount of haloalkyl-substituted olefin, which is thermostatted at 70.degree.
• 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 cooled and washed three times with the same amount of water to remove the propionic acid. The propionic acid-free reaction mixture is then fractionated.
• reaction mixture was washed several times with water to remove the propionic acid, benzene was distilled off and then fractionated in a 10 cm packed column filled with 4 mm glass Rasching rings. 18.9 g of 2- (1,2-dichloroethyl) oxirane with a purity of 99.4% were isolated.
• This reaction system was fed 2,137.5 g perpropionic acid as a 20% solution in benzene (4.75 mol) and 1,781.25 g (14.25 mol) 1,4-dichloro-2-butene per hour, which had an average residence time of corresponded to about 8 hours. Under these reaction conditions, 96.8% of the perpropionic acid was converted. The selectivity of the 2,3-bis (chloromethyl) oxirane formed was 96%, based on the perpropionic acid used.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Epoxy Compounds (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=6015053

Family Applications (1)

Country Status (6)

Cited By (1)

Citations (2)

• 1977
  • 1977-07-28 DE DE19772734086 patent/DE2734086A1/de not_active Withdrawn
• 1978
  • 1978-07-20 EP EP19780100457 patent/EP0000555B1/fr not_active Expired
  • 1978-07-20 DE DE7878100457T patent/DE2861620D1/de not_active Expired
  • 1978-07-26 DD DD20695678A patent/DD138066A5/xx unknown
  • 1978-07-26 CA CA000308194A patent/CA1120048A/fr not_active Expired
  • 1978-07-26 JP JP9056878A patent/JPS5427514A/ja active Granted
  • 1978-07-26 AT AT544678A patent/AT358058B/de not_active IP Right Cessation

Patent Citations (2)

Also Published As

Similar Documents

Legal Events