Method of producing high-purity, halogen-free o- phthalaldehyde

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing high-purity, halogen-free o-phthalaldehyde, having gas chromatography (GC) purity >99.5% of area, which can be used as an intermediate compound in production of paint, optical clarifying agent, in biocidal industry or photography. The disclosed method comprises the following steps: a) hydrolysis of tetrahalo-o-xylene at temperature 155-160°C and pressure 2-5 bars to o-phthalaldehyde which is b) converted in an acidic alcohol solution at temperature ranging from 0°C to boiling point with a reflux condenser to the corresponding dialkoxyphthalane and further, c) acetal is decomposed via acid hydrolysis at pH ranging from >1.5 to 7, thereby obtaining highly pure, halogen-free o-phthalaldehyde.

EFFECT: efficient method of producing high-purity, halogen-free o-phthalaldehyde.

5 cl, 1 ex

 

Phthalaldehyde, such as o-phthalaldehyde (OFA), is used in many areas as intermediates for producing paints, optical brighteners or special polymers, biocide or photographic industry, and for the synthesis of farmakonisi drugs. Some variants of the method described. Thus, phthalaldehyde (OFA) can, for example, according to EP-B-0147593, get ozonolysis of naphthalene in methanol and a catalytic recovery of the resulting peroxides and their subsequent extraction or crystallization. The disadvantage of this method is that the ester, which is formed as a by-product, it is difficult separates from OFA.

In addition, OFA is a reactive compound which is thermally unstable and to oxidation, and which, if prolonged storage is prone to clumping, thus making it necessary to conduct long-term dissolution processes, which can lead to discoloration OFA. The opportunity described in EP-A1-0522312 to protect the aldehyde from undesirable reactions is the use of tetraalkylated o-phtalaldehyde, obtained by electrochemical oxidation, as compounds capable of long-term storage.

EP-IN-0839789 additionally describes the transformation OFA with the formation of the acetal is ri catalysis acid, with subsequent distillation in a suitable storage connection, such as, for example, dialogtitle or tetraalkylated, from which, if necessary, get soggy OFA with a purity of more than 99.5% after complete decomposition of the acetal acid hydrolysis.

However, raw OFA, for example, obtained according to EP-B-0 839 789, has a reddish-orange color, and the necessary subsequent recrystallization to bleaching, for example, activated carbon or Tonsil.

Fine powder OFA with a melting point of 57°C, which is obtained by crystallization, it is also prone to clumping. In addition, the different parties do not show a permanent colour and quality.

U.S. patent 5107032 describes the receipt OFA using was tetragona-o-xylene, followed by hydrolysis at 90 to 146°C. Is carried out, for example, by hydrolysis was tetragona-o-xylene with sodium acetate in aqueous acetic acid solution at a maximum temperature of 146°C and 3.5 bar, then 5-fold extraction with toluene and subsequent distillation of the combined organic phases gives the output OFA 87%. However, the disadvantage of this method is that the resulting product is not free from halogen.

Therefore, the aim of the present invention was to find an improved method of obtaining high purity, free from Halogens OFA.

Suddenly it was possible to achieve specified the second hydrolysis was tetragona-o-xylene at temperatures above 155°C, subsequent acetalization in the corresponding acetal o-phtalaldehyde, cleaning acetal by distillation and decomposition of the acetal at pH >1,5.

The invention, therefore, relates to a method for producing high-purity, free from halogen on-phthalaldehyde, which includes:

a) hydrolysis was tetragona-o-xylene at a temperature of from 155°C to 160°C and a pressure of from 2 to 5 bar, if appropriate, in the presence of a phase transfer catalyst, o-phthalaldehyde,

b) turning on-phthalaldehyde in acidic alcohol solution at a temperature of from 0 the boiling point under reflux in an appropriate dialogtitle and then

(C) decomposition of the acetal acid hydrolysis at a pH of >1.5 to pH 7 with getting vysokochastotnogo free from halogen on-phthalaldehyde.

High-purity, free from halogen on-phtalaldehyde (OFA) are obtained according to the method of the invention.

The original substance is was tetragona-o-xylene. Fit was tetragona-o-xylenes are, for example, the compounds of formula

in which X can be Cl, Br or I.

Was tetragona-o-xylene (THC), in addition, may be optionally substituted by one or more suitable radicals. Suitable radicals are1-C4alkyl, C5-C20aryl, HE, NO2CN, Cl, Br or CO2N.

PR is doctitle, if used unsubstituted THC compounds, and X preferably represents chlorine.

Suitable THC compounds commercially available (with X equal to Cl or Br) or can be obtained in a known manner, for example, by the reaction of o-xylene with elemental chlorine in the light or using free-radical initiators, such as AIBN, PCl3and Dibenzoyl peroxide, etc.

THC hydrolized according to the invention at a temperature of from 155°C to 160°C and a pressure of from 2 to 5 bar, preferably from 3 to 4 bar, the corresponding o-phthalaldehyde.

The hydrolysis is carried out in an aqueous system consisting of a1-C4carboxylic acids in the presence of a base, such as NaOH, LiOH, KOH, etc. is Preferable to use acetic acid in the presence of NaOH (40 to 50%).

For this purpose carboxylic acid or an aqueous solution of carboxylic acid and THC, preferably, mix and then add an aqueous solution of a base and water. The sequence of addition can be changed.

The amount of carboxylic acid is from >4 to 20 molar equivalents, based on TGC. Preferably from 8 to 10 molar equivalents, based on TGC.

The amount of base is from 4.0 to 5.0 molar equivalents, based on TGC.

Can be added to the reaction mixture catalysts interfacial transfer is to achieve higher speeds (IFC) (from 1 to 5 mol.%, based on TGCs). Suitable IFC are conventional compounds such as, for example, Quaternary ammonium salts and postname salts, for example salts of tetraalkylammonium and tetraallylsilane or salt of arylalkylamine. Preferred salts in this context are the halides, for example chloride or bromide tetrabutylammonium, chloride ethyltrichlorosilane, chloride of benzyltriethylammonium etc.

After hydrolysis of the corresponding crude o-phtalaldehyde (OFA) was isolated by extraction conventional extractants, such as, for example, methyl tertiary butyl ether, toluene, ethyl acetate, etc. and the subsequent distillation of the solvents and extractants.

Then, in stage b) raw OFA converted into acetal, dialogtitle, acetalization acid catalyzed with alcohol.

The preferred alcohol in this case is1-C4alcohol especially preferred methanol or ethanol.

Raw OFA for this purpose is dissolved in alcohol. The solution is then adjusted to a pH of from 0 to 3, preferably from 0.5 to 2, the addition of acid.

Suitable acids are mineral acids, such as HCl, H2SO4H3PO4such organic acids, such as formic acid, acetic acid, p-toluensulfonate or methansulfonate acid or acid ion is exchangers.

The temperature at this stage is from 0°C to the boiling temperature under reflux, preferably to 50°C.

After acetalization aqueous solution of alkali added to the solution to neutralize the acid or acidic organic compounds. NaOH or KOH suitable as alkali.

The alcohol used as solvent is removed by distillation and then or simultaneously.

Dialogtitle, in turn, emit extraction and subsequent distillation. Selected OFA acetals in this case are very high, free from Halogens quality (>99,5 GC % of the area) and very high yield of more than 92%.

Decomposition of acetals in stage C) is also carried out in the usual way known from the prior art by acid hydrolysis.

the pH is >1.5 to 7, preferably from 1.6 to 2.5, according to the invention.

Used acid are mineral acids such as HCl, H2SO4H3PO4or such organic acids as acetic acid, formic acid and p-toluensulfonate or methansulfonate acid. The reaction temperature, preferably from room temperature to 60°C. At the same time Argonauts remove the alcohol and, where possible, in acid. Data obtained by means OFA can then be further cleaned, where suitable, for example, extraction, otravlyaly crystallization.

OFA receive very high, free from Halogens quality (>99,5 GC % of the area) and very high output up to over 92% of the cleanup method of the invention. In addition, OFA, purified according to the invention, shows a constant color and does not need any discoloration by using Tonsil or coal. In addition, using the method of the invention avoids the loss of output OFA.

The method of the invention additionally is reaction time, which is shorter than that of the prior art, thus making possible a continuous process.

Example 1

Step (a)

61 g (0.25 mole) of tetrachloro-o-xylene (TCA) (purity 99%) was introduced into the autoclave and added 300 g (5 mol) of acetic acid. Then was slowly added a solution of 44 g (1.1 mol) of NaOH and 198 g of deionized water.

The reaction mixture was heated to 160°C. and kept at the specified temperature for 1 h, the Reaction pressure was 3,8-3,9 bar.

Then the mixture was cooled to 40°C. and was discharged from the autoclave (606 g=525 ml of reaction solution).

A sample of 2 ml was collected and analyzed.

The result: 99,43 GC % area raw OFA.

Extraction of crude OFA:

606 g of the crude solution OFA first was mixed with 50 ml of deionized water and then was extracted 4 times with 93 g of MTBE.

The organic phases were combined and concentrated on a rotary evaporator in vacuum 400-450 MB the R and 34-72°C to stop the distillation.

After evaporation was obtained 54 g of residue.

Step b)

All the residue after evaporation was mixed with 375 ml of methanol was added 2 ml conc. H2SO4to bring the pH to 0.5.

After 2 hours at 50°C. was added 50% NaOH solution. The reaction mixture was then concentrated on a rotary evaporator and then was mixed with 175 ml of deionized water and was extracted with 3×80 ml MTBE at 25°C.

The organic phases were combined and concentrated on a rotary evaporator.

The final weight 42,4,

The crude acetal was distilled at a bath temperature of 135-140°C, the temperature of the cube 113-114°C and the temperature of the upper shoulder strap 110-111°C. the Pressure ranged from 8 to 10 bar.

Final weight: 41,2 g OFA of dimethoxyacetate (91% of theory).

Step C) decomposition OFA of dimethoxyacetate:

200 g of OFA dimethoxyacetate was added to 500 g of deionized water, which was brought to a pH of 2.0 with sulfuric acid, and the pressure was reduced to about 150 mbar. Then started heating up. The selection of distillate was started when the temperature of the cube 53°C and 155 mbar. Total received 270 ml of distillate. IPC-GC analysis of the organic phase after 4 h showed 99.89 per cent of the area OFA.

After adding 500 ml of DIPE OFA was extracted at 50°C. After separation of the phases the organic phase every time washed 2×100 ml deionized water.

Washed pale yellow coloured organic solution was boiled with reverse, chilling the nick and water, remaining in the organic phase were removed as azeotrope at atmospheric pressure. Total received to 9.5 ml of water.

Then began the slow cooling. Crystallization OFA began at 42°C. Additional cooling is continued up to 15°C.

Crystal OFA filtered through G-2 a Frit, washed with 150 ml of DIPE and dried in vacuum at 40-45°C during the night. Allocated 91,5 g dry OFA content >99.8 per cent and 450 ml stock solution. The output amounted to 61.5% of theory.

Missing up to 100% of theory OFA was present in the mother solution in the water after decomposition in water after washing, all of which could be reused in the next cycle of deacetylases, due to the high purity and the pale color of the solutions. Quantitative deacetylase was in this way possible.

1. The method of obtaining high-purity o-phtalaldehyde, free from Halogens, having a purity of >99,5 GC % area, which includes:
a) hydrolysis was tetragona-o-xylene at a temperature of 155-160°C and a pressure of from 2 to 5 bar to about-phthalaldehyde, which
b) turn in acidic alcohol solution at a temperature from 0°C to the boiling point under reflux in an appropriate dialogtitle, and then
c) acetal is decomposed by acid hydrolysis at a pH of >1.5 to pH 7, obtaining high-purity free from halogen on-phthalaldehyde.

2. Ways who according to claim 1, in which stage a) is carried out in C1-C4carboxylic acid in the presence of a base and water.

3. The method according to claim 2, in which the number of applied carboxylic acid is from >4 to 20 molar equivalents, based on was tetragona-o-xylene.

4. The method according to claim 1, wherein stage b) is carried out at a pH of from 0 to 3.

5. The method according to claim 1, in which stage C) is carried out at a pH of from 1.6 to 2.5.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: present invention relates to a method for synthesis of 3,3,3-trifluoropropanal, which is used in production of herbicides, various pharmaceutical preparations and fluorine-containing polymers. The method involves a stage where alcohol reacts with halogenated hydrocarbon in the presence of a base, obtaining 3,3,3-trifluoromethylvinyl ether at temperature not above 50°C, and a stage for hydrolysis of 3,3,3-trifluoromethylvinyl ether in the presence of sulphuric acid as a catalyst at high temperature. The halogenated hydrocarbon used at the first stage is 1,2-dibromo-3,3,3-trifluoropropane, and the alcohol used is isopropyl alcohol to obtain isopropyl-3,3,3-trifluoromethylvinyl ether, which is subjected to hydrolysis at the second stage. As a rule, the catalyst used at the second stage is concentrated sulphuric acid, and the base used at the first stage is a hydroxide of an alkali metal, selected from potassium or sodium hydroxide.

EFFECT: obtaining an end product with high output using cheaper starting compounds and the method does not require additional stages for purifying starting compounds.

3 cl, 3 ex

The invention relates to a new method for the preparation of 3-(n-propyl)ALK-3-EN-2-ones of General formula CH3C(O)C(C3H7)=СНR, where R=n-C6H13n-C8H17the interaction of compounds RCH=C=CH2with AlEt3when a molar ratio of 10:(10-14), in the presence of a catalyst Cp2ZrCl2taken in the amount of 2-6 mol.% in relation to the original Allen in an argon atmosphere at room temperature and normal pressure in methylene chloride for 5 h, and then adding to the reaction mass acetonitrile (CH3N), taken in a 3-fold excess relative to triethylaluminium, stirring at a temperature of 40oC for 4-8 h and subsequent acid hydrolysis of the reaction mass

FIELD: chemistry.

SUBSTANCE: present invention relates to a method for synthesis of 3,3,3-trifluoropropanal, which is used in production of herbicides, various pharmaceutical preparations and fluorine-containing polymers. The method involves a stage where alcohol reacts with halogenated hydrocarbon in the presence of a base, obtaining 3,3,3-trifluoromethylvinyl ether at temperature not above 50°C, and a stage for hydrolysis of 3,3,3-trifluoromethylvinyl ether in the presence of sulphuric acid as a catalyst at high temperature. The halogenated hydrocarbon used at the first stage is 1,2-dibromo-3,3,3-trifluoropropane, and the alcohol used is isopropyl alcohol to obtain isopropyl-3,3,3-trifluoromethylvinyl ether, which is subjected to hydrolysis at the second stage. As a rule, the catalyst used at the second stage is concentrated sulphuric acid, and the base used at the first stage is a hydroxide of an alkali metal, selected from potassium or sodium hydroxide.

EFFECT: obtaining an end product with high output using cheaper starting compounds and the method does not require additional stages for purifying starting compounds.

3 cl, 3 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing high-purity, halogen-free o-phthalaldehyde, having gas chromatography (GC) purity >99.5% of area, which can be used as an intermediate compound in production of paint, optical clarifying agent, in biocidal industry or photography. The disclosed method comprises the following steps: a) hydrolysis of tetrahalo-o-xylene at temperature 155-160°C and pressure 2-5 bars to o-phthalaldehyde which is b) converted in an acidic alcohol solution at temperature ranging from 0°C to boiling point with a reflux condenser to the corresponding dialkoxyphthalane and further, c) acetal is decomposed via acid hydrolysis at pH ranging from >1.5 to 7, thereby obtaining highly pure, halogen-free o-phthalaldehyde.

EFFECT: efficient method of producing high-purity, halogen-free o-phthalaldehyde.

5 cl, 1 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing high-purity, halogen-free o-phthalaldehyde, having gas chromatography (GC) purity >99.5% of area, which can be used as an intermediate compound in production of paint, optical clarifying agent, in biocidal industry or photography. The disclosed method comprises the following steps: a) hydrolysis of tetrahalo-o-xylene at temperature 155-160°C and pressure 2-5 bars to o-phthalaldehyde which is b) converted in an acidic alcohol solution at temperature ranging from 0°C to boiling point with a reflux condenser to the corresponding dialkoxyphthalane and further, c) acetal is decomposed via acid hydrolysis at pH ranging from >1.5 to 7, thereby obtaining highly pure, halogen-free o-phthalaldehyde.

EFFECT: efficient method of producing high-purity, halogen-free o-phthalaldehyde.

5 cl, 1 ex

FIELD: chemistry.

SUBSTANCE: terephthalic aldehyde is obtained from α,α,α',α'-tetrabromo-p-xylene while heating, followed by extraction of the end product. The method includes reacting α,α,α',α'-tetrabromo-p-xylene with O,O-dimethyl methylphosphonate at 180°C, and the end product is extracted from the reaction mass with isooctane.

EFFECT: method enables to obtain an end product with high output using a simple technique.

2 ex

FIELD: chemistry.

SUBSTANCE: method is to interact α,α,α',α'-tetrabrom-p-xylene with dimethyl acetal of benzaldehyde in the presence of the catalytic amount of zinc chloride at the temperature of 80°C, followed by isolation of the desired product by extraction from the reaction mixture with hot isooctane.

EFFECT: producing the desired product with high yield.

2 ex

FIELD: chemistry.

SUBSTANCE: method is to interact α,α,α',α'-tetrabrom-p-xylene with dimethyl acetal of benzaldehyde in the presence of a catalytic amount of zinc chloride at the temperature of 50°C, followed by isolation of the desired product by extraction from the reaction mixture with hot isooctane.

EFFECT: producing the desired product with high yield.

3 ex

Up!