CS270178B1 - Method of 3-oxo till 12-oxo-alkano-carboxylic acids production - Google Patents

Abstract

solution the bull section"} organic chemistry and organic technology. solves training oxoalkanoic carboxylic ky Selin ozonation each cycloalk new Moon containing at least 3 carbon alpha pyrrolinyl, pyrrolidinyl in molecule and having duplex bond between two terciáraymi carbon. / Ozoni- sation the going in environment reactive solvent. Product ozonolysis the extended dispersed or zemulguje water la hydro lyses the on the oxoalkanoic of general him of formula I H > - (° H 2> x - ΌΗ. / / I and h. The essence is a it that ozonation cycloalk new Moon and hydrolytic decomposition product the ozone ation underway and preferably in relaktoroch with scraped film liquid. solution is a possible use for training oxo-alkanes dumping carboxylic acid from cycloalkenes. reactions underway with high selectivity.

Description

The present invention relates to a process for the preparation of 3-oxo- to 12-oxo-alkanoic carboxylic acids by ozonation of cycloalkenes and subsequent hydrolytic decomposition of the ozonation product and isolation of the target product from the reaction mixture.

NSR patent δ. No. 3,005,514 protects the ozonolysis of 1- and 2-alkenes containing 8 to 30 carbon atoms in the molecule by treating ozone to an aqueous emulsion of a solution of the starting material in an organic solvent, followed by hydrolytic decomposition of the ozonation product. The liquid and gaseous reactants are simultaneously brought into contact in the reactor, where aa forms a turbulently flowing liquid film. The gaseous reactant moves in the reactor in a turbulent zigzag flow over or through the film of liquid at a faster rate calculated on an empty scale of at least 2 ms ^-1 with a residence time of at most 2 seconds. The reactor is filled with geometrically regular filler bodies with a surface area of more than 10 m .m. The resulting heat of reaction is removed by evaporating water in situ. Preferably, reactors are applied consisting of a bundle of tubes.

The author's certificate CSRR 249 240 heats the process for the simultaneous production of aldehydes and monocarboxylic acids by ozonation of organic substances containing a double bond on the secondary and tertiary carbon or on the tertiary carbons of the hydrocarbon chain.

The ozonation takes place in a reactor with a wiped film of liquid in a reactive solvent medium. After emulsification with water, the ozonation product is hydrolyzed in a second reactor, preferably a liquid film wiper reactor, and the monocarboxylic acids and aldehydes are isolated from the reaction mixture by physical processes or a combination thereof.

The present invention relates to a process for the preparation of 3-oxo- to 12-oxo-alkanoic carboxylic acids of the general formula

H O

- r - c ^ (Γ OH, where R is one to ten -CH 2 - and / or

- groups, wherein R ₁ is an alkyl, cycloalkyl or phenyl chain containing one to 8 carbon atoms.

The object of the invention is that the individual cycloalkenes in the molecule having a double bond between two tertiary carbons, or mixtures thereof, are dissolved in a reactive solvent and the resulting solution is brought into contact with ozone. Subsequently, the reaction mixture is hydrolyzed with water to give oxoalkanoic acids.

The starting material for this process can be individual cycloalkenes containing three to twelve carbon atoms in the cycloalkene ring or mixtures thereof. Examples are cyclopropene and its alkyl derivatives, cyclobutene and its alkyl derivatives, cyclopentene, cyclohexene, cycloheptene, cyclononene, cyclodecene, cycloundecene and cyclododecene and their alkyl and / or cycloalkyl and / or phenyl derivatives. The alkyl, cycloalkyl and phenyl radicals contain one to eight carbon atoms.

The reactive solvent may be either individual carboxylic acids containing 1 to 6 carbon atoms in the molecule or any mixtures thereof such as methane to hexanoic acid or mixtures thereof, dicarboxylic aliphatic acids or mixtures thereof. Individual alcohols containing 1 to 6 carbon atoms in the molecule can also be used as reactive solvents, for example methanol to hexanol or mixtures thereof or individual diols or mixtures thereof such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, or mixtures of acids and alcohols. Where physicochemical properties allow, generic oxoalkane carboxylic acids or mixtures thereof with C ₁ to C 8 acids and / or alcohols are preferably used as the reactive solvent. If generic aldehyde acids are used as the reactive solvent, it is not necessary to isolate them from the ozonation product, but only to remove part of them from the process.

CS 270 ’3 Bl

The choice of reactive solvent is determined by its physical properties such as solidification temperature, boiling point and its chemical reactivity. The low solidification temperature of the reactive solvent allows the ozonation of the starting material at low temperatures even in the presence of water, which is important in the ozonation of volatile substances or substances in which volatiles are formed. The boiling point of the reactive solvent should preferably differ by at least 20 ° C from the boiling point of the target product.

The reactive solvents should be able to react with ozonide to form more chemically stable ester hydroperoxides and / or alkoxyhydroperoxides.

The concentration of the starting material in the reactive solvent can be in the range from 5 to 50% by weight. The working limit of the concentration of the starting material in the reactive solvent is given by the economics of the process, possibly soluble by one hundred starting materials, intermediates and ozonation products in the reactive solvent in order to avoid the formation of two liquid phases. The upper limit of 50% by weight of the starting material in the reactive solvent is given by the preference for ozonation by the mechanism of formation of ester hydroperoxides and / or alkoxyhydroperoxides.

Ozone formed at a concentration of 0.5 to 10% by weight. it can be diluted with oxygen, air, an inert gas such as argon, krypton, xenon, neon, helium or CO 2. Nitrogen can also be used to dilute ozone. However, undesirable nitrogen oxides are formed in its presence. The zone can also be diluted with a mixture of oxygen, inert gases, nitrogen and carbon dioxide. The upper limit of the ozone concentration in the diluting gas is given both by the economics of its preparation and by the possibility of removing heat of reaction.

The ratio of ozone to cycloalkene or cycloalkene moiety may be in the range of 0.8 to 1.2, preferably 1.05 to 1.15. A certain excess of ozone is to compensate for its recombination to oxygen, thus reducing the consumption of ozone for the side reaction.

The temperature in the ozonation reactor depends on the molar mass of the starting material and on the type of reactive solvent used. When varying from -60 ° C to 60 ° C.

The pressure in the ozonation reactor depends on the molar mass of the reactive solvent, on the molar mass of the target oxoalkanoic carboxylic acid, on the temperature in the ozonation reactor and on the strength of the glass parts of the ozonator. It can range from 0.01 MPa to 0.5 MPa.

The product withdrawn from the ozonation reactor is heated to a temperature above 0 ° C and dispersed or emulsified with water if the ozonation takes place at a temperature below 0 ° C. The dispersion or emulsification of the water and the ozonation product can be carried out mechanically, optionally with the aid of anionic or nonionic surfactants. The molar ratio of ozonation product to water can range from 1: 1 to 1:50.

The dispersion or emulsion of water with the ozonation product is pumped into a hydrolysis reactor in which the temperature is maintained between 70 ° C and 120 ° C and the pressure is between 0.1 and 0.5 MPa.

The hydrolysis product can be drawn into the condenser * from there either. to a fractionation column, or to a set of fractionation columns, or for purification. The target product can be purified by adsorption, extraction or crystallization. After its separation from the target product, the reactive solvent is returned to the reaction.

The products of the process according to the invention are 3-oxo-propane, 4-oxo-butane, 5-oxo-pentane, 6-oxo-hexane, 7-oxo-heptane, e-oxo-octane, 9-oxo-nonane, 10- oxo-decanoic, 11-oxo-undecanoic and 12-oxo-dodecanoic carboxylic acid, mixtures thereof and their derivatives.

The advantage of the process according to the invention is that complete conversion of the cycloalkenes is achieved and the selectivity for the formation of oxo-alkanoic carboxylic acids exceeds well over 90%.

The following examples are provided by way of illustration and not by way of limitation.

CS 270 178 Bl 3

Examples 1 to 5

In all examples, a unified procedure is used, generally described in the following text.

The conditions of ozonation, hydrolysis of the ozonation product and analysis of the target products are given in the table. .

The cycloalkene J soluble in the reactive solvent 2 at a concentration of 3 is pumped in an amount of 4 into an ozonation reactor with a liquid film wiping.

Ozone in the molar ratio to the cycloalkene 5 with a concentration of 6 in the noene gas 7 flows countercurrent to the feedstock.

The temperature in the liquid wiped film is 8 and the pressure in the ozonation reactor is 9.

The ozonation product decomposes hydrolytically with water. The free ratio of ozonation product to water is J0, the temperature of the liquid film of the hydrolysis reactor is JJ and the pressure is J2.

The conversion is complete, the acid yield is J3, their purity is J4.

The name of the oxoalkanoic carboxylic acid as the separation product is J5.

Table 'Preparation of oxoalkanoic carboxylic acids in

Ozonation J Hydrolysis Analysis

Entrance. Pads. Entry Conditions Products

Example note ______ cycloalkene • reactive solvent concentration of the cycloalkene in the solvent 'raw material' spray 'molar ratio of ozone' to cycloalkene 1 concentration of ozone. carrier gas. 1 temperature in the film of ozonized raw material pressure in the ozonation reactor 1 molar ratio of ozonation product to water · The temperature in the film drops hydr. reactor pressure in the hydrolysis reactor oxoalkanoic acid extract purity of oxoalkanoic acid flax ...... the name of the oxoalkanoic carboxylic acid of the general formula H 2 O ' ^S C - R - C 0 ^ ^X 0H % wt kgjcycloalkene _m 2 h “m» n : h · i ^In C MPa ’C 1 Pa % wt % wt • • 1 ·; 2 3 4Í ' 5 6 7 8 9 10 11 2 ’3 H 15 1 cyclododecene ! cyclooctene 3 cyclohexene 4 cyclopentene > cyclo- | xitene kys. ' hexanoic acid. butenoic acid. ethanoic acid. methane acid. new goal 25 15 30 15 10 30 as: 32 15 10 1.10 1.05 1.00 1.2 1.05 5.0 8.0 3.5 9.4 8.0 cysltk cyšl i kyslfk argon oxygen 20 25 30 -15 -30 0.11 0.15 0.20 °, i 0.4 16 l »30 1:10 1:50 Ii5 95 100 110 85 80 1.12 1.15 > 3 1.4 1.5 98.5 99. 99.5 97.5 97 99 98.5 98.5 97 98 12-oxo-dodecane 8-oxo-octane 6-oxo-hexane 5-oxo-pentane 4-oxo-butane

CS 270 178 Bl

Claims (1)

P R E D Μ E T OF THE INVENTION Process for the preparation of 3-oxo- to 12-oxo-alkanoic carboxylic acids of general formula wherein R is one to ten -CH 2 - and / or. · -CH- groups, wherein R ₁ is an alkyl, cycloalkyl or phenyl chain containing up to eight carbon atoms, characterized in that by introducing individual cycloalkenes containing 3 to 12 carbon atoms in the cycloalkene chain and having a double bond between the court tertiary carbons, or mixtures thereof, in a reactive solvent type of individual organic carboxylic acids and / or alcohols containing 1 to 6 carbon _{atoms (} atoms). in the molecule, and / or individual generic oxoalkanoic acids and / or mixtures thereof with a concentration of cycloalkene raw material in a solvent of 5 to 50% by weight, in contact with ozone in a molar ratio of ozone to cycloalkene raw material of 0.8 to 1.2 at -60 ° C to 60 ° C, at a pressure of 0.01 MPa to 0.5 MPa, then the ozonation product is hydrolyzed with water in a molar ratio of water to ozonation product of 1.0 to 50: 1, at a temperature of 70 ° C to 120 ° C. C and at a pressure of 0.1 to 0.5 MPa and the reactive dispersant is returned to the process after separation from the reaction mixture.