HU202466B - Process for purifying and stabilizing 2-(trifluoro-methyl)-phenol and 4-(trifluoro-methyl)-phenol - Google Patents

Abstract

According to the invention, the purification process is carried out by distillation at a temperature of from 50 to 150 ° C in the presence of at least 0.1% silicone oil, and a 1 part silicone oil additive is used for stabilization at 10,000 parts by weight of 2-trifluoromethyl or 4 - (for trifluoromethyl-phenol. HU 202466B Scope of the description: 3 pages, without figure -1-

Description

The present invention relates to a process for the purification and stabilization of 2- (trifluoromethyl) phenol and 4- (trifluoromethyl) phenol.

The literature (J. Am. Chem. Soc. 69, 2346-50) and our own experience show that 2- (trifluoromethyl) phenol and 4- (trifluoromethyl) phenol are extremely labile compounds. In the presence of trace amounts of alkali or hydrogen fluoride, polymerization processes take place. Given that the moisture content of the air results in the formation of hydrogen fluoride during the hydrolysis of the trifluoromethyl group, the polymerization processes present problems both during purification by distillation and during storage.

It is an object of the present invention to provide a method for stabilizing 2- (trifluoromethyl) phenol and 4- (trifluoromethyl) phenol by which the polymerization processes can be inhibited or delayed, allowing for vacuum distillation purification and long-term storage without deterioration.

The stabilization method of the present invention is based on the discovery that the stability of 2- (trifluoromethyl) phenol and 4- (trifluoromethyl) phenol can be significantly increased by the addition of a silicone oil additive to trace hydrogen fluoride.

In the purification process of the invention, 2- (trifluoromethyl) and 4- (trifluoromethyl) phenol containing at least 0.1% silicone oil are distilled in vacuo at 50-150 ° C.

In the stabilization process of the invention, at least 1 part by weight of silicone oil is added to 10,000 parts by weight of 2- (trifluoromethyl) and 4- (trifluoromethyl) phenol.

The purification and stabilization methods can be used to prevent or delay polymerization processes, regardless of the method of preparation of the phenol derivatives. In a preferred embodiment of the purification process of the invention, the crude product containing 1-3% silicone oil is distilled at a head temperature of 70-100 ° C by condensing the distillates at 50-60 ° C.

An advantage of the purification and stabilization process of the present invention is that the use of silicone oil as a stabilizer enables the safe purification of crude 2- (trifluoromethyl) phenol and 4- (trifluoromethyl) phenol by vacuum distillation, a high quality product. production and storage without deterioration.

The invention is illustrated by the following non-limiting examples.

Example 1

Vacuum distillation purification of 2- (trifluoromethyl) phenol and 4- (trifluoromethyl) phenol

In our study vacuum distillation experiments were carried out with 1000 g of 84% crude 430 - (trifluoromethyl) phenol (substance A) and 85% crude 2 - (trifluoromethyl) phenol (substance B). was performed at different distillation head temperatures using different amounts of silicone oil additive. A commercially available silicone oil, Silorol-M, was used for the test series.

Our results are summarized in Table I below.

spreadsheet

First

Sign of the test substance Silorol-M Quantity added to 1000 g of raw material (G) Vacuum distillation head temperature (° C) The final product Cleanliness (Wt%) The starting material Yield based on phenol content (%, THE 0 50-55 95 42 THE 0 80-85 92 18 THE 0.5 80-85 97 69 THE 1 80-85 99 95 THE 20 50-55 99 98 THE 20 80-85 98.5 98.5 THE 100 80-85 99 98 B 0 90-95 97 68 B 0 140-150 94 47 B 0.5 90-95 98 76 B 1 90-95 99 96 B 20 90-95 98.5 98.5 B 20 140-150 98 94 B 100 90-95 99 98

Example 2

Investigation of the stabilizing effect of silicone oil during storage

For our studies, 97% by weight (substance C) and 99% by volume of 4- (trifluoromethyl) phenol (substance D) and 98 tX of 2-trifluoromethylphenol (substance E) We were used.

Samples of the materials used in the experiment were prepared using commercially available silicone oil, Silorol-M, containing 0.1-5.0 tX of silicone oil.

2 g of samples prepared using materials C and D were heat treated at 100 ° C and samples made from material E at 120 ° C. Materials without silicone oil were used as standard. The induction time required to start the polymerization was determined. The measured induction times (in. Minutes) are shown in Table II. are summarized in Table.

II. spreadsheet

Symbol of the material used for the sample Concentration of Silorol-M 0% 0.1% 0.5% 1.0% 2.0 tX 5.0 tX C 60 115 300 - 850 > 1200 D 45 55 - 225 - - E 60 60 - 180 - > 1200

Storage materials were tested at 40 room temperature using materials A and C. Samples containing 10 g of Silorol-M weighing 0.1 g and 0.01 tX were prepared and the induction times were determined. Ten replicate measurements were performed, which resulted in samples containing 0.1 tX silicone oil for 2-3 months and samples containing 0.01 tX silicone oil for 3-4 weeks without deterioration, whereas the standards without silicone oil had 50 time was only 3-7 days.

Claims (7)

PATENT CLAIMS A process for the purification of 2- (trifluoromethyl) phenol and 4- (trifluoromethyl) phenol, characterized in that it contains 2- (trifluoromethyl) - or 4- (trifluoromethyl) containing at least 0.1 tX of silicone oil. ) -phenol is distilled in vacuo at 50-150 ° C. 2. A process for stabilizing 2-trifluoromethylphenol and 4- (trifluoromethyl) phenol, wherein at least 10,000 parts by weight of 2- (trifluoromethyl) or 4- (trifluoromethyl) phenol are present. 1 part by weight of silicone oil was added. Published by the National Office for Inventions, Budapest Responsible: dr. Gabriella Swaboda Head of Department R 4991 - KJK 91.3994.66-13-2 Alföldi Nyomda Debrecen - Chief Executive Officer: Viktor Szabó Chief Executive Officer -3 (19) Country Code: HU PATENT DESCRIPTION (11) 202467 B (22) Filed on 06.05.1987. (21) 2023/87 (30) Notification priority: (P 36 16 057.1) 13.05.1986. DE (51) Int Cl ⁵ C 07 C 45/50 C 07 F 9/50 B 01 J 31/02 ENGLISH (40) REPUBLIC NATIONAL INVENTIONS (45) OFFICE Posted on Mar 28, 1988 Date of Publication of the Publication in the Patent Gazette: 28.03.1991. (72) Inventors: dr. BACH Hanswilhelm, Duisburg, dr. BAHRMANN Helmut, Hamminkeln-Brünen, dr. CORNILS Boy, Hofheim, dr. KONKOL Werner, WIEBUS Ernst Oberhausen, (DE) (73) Ruhrchemie AG., Oberhausen, (DE) (54) PROCESS FOR THE PRODUCTION OF ALDEHYDES (57) The present invention relates to the preparation of aldehydes by reacting olefinically unsaturated compounds with an aqueous medium in the presence of water-soluble rhodium complex compounds as a catalyst. In order to shorten the reaction time of the initial phase and to avoid loss of precious metal, the catalyst is pre-formed under defined reaction conditions. HU 202467 B 1 description scope: 5 pages, 1 drawing, 1 figure HU 202167 Β The present invention relates to an improved process for the preparation of aldehydes from olefinically unsaturated compounds by reaction with an aqueous medium in the presence of a water-soluble rhodium complex compound as a catalyst. It is an object of the present invention to shorten the reaction time in the initial stage of the reaction by pre-forming the catalyst and preventing the precious metal from being released during this stage of the reaction. It is known that aldehydes and alcohols can be prepared by reacting olefins with carbon monoxide and hydrogen. The reaction is catalyzed by hydrocarbon-carbonyls, especially hydrocarbonyl compounds of the metals of the Group 8 of the Periodic Table. Cobalt catalysts have been used in various technical solutions of the classical process. Recently, the use of rhodium catalysts has become increasingly popular. The rhodium catalyst component, unlike cobalt, allows the reaction to be carried out at low pressure, and preferably straight chain n-aldehydes are formed while the isoaldehydes are formed only in a minor amount. A further advantage is that the further hydrogenation (side reaction) of olefins to saturated hydrocarbons in the presence of rhodium catalysts is substantially less than that of cobalt catalysts. In the prior art, modified hydride rhodium carbonyl is used as the rhodium catalyst, i.e. compounds containing hydrogen and carbon monoxide in addition to rhodium and at least one additional ligand. Organic compounds of the group Va of the periodic table and esters (e.g., esters of phosphoric acid or arsenic acid) may be used as ligands. Particularly preferred are tertiary phosphines or phosphites. These compounds are generally used in excess and form part of the reaction medium. Among the hydroformylation processes employing modified hydrideorodium carbonyls as catalysts, U.S. Pat. No. 2,627,354. The process described in the German patent specification of the Federal Republic of Germany deserves special mention. The process involves the reaction of olefin, carbon monoxide and hydrogen in a liquid phase in the presence of water and water-soluble rhodium complex. The solubility of rhodium complex compounds is ensured by using sulfonated triarylphosphines as one component of the complex. This method has a number of significant advantages. The reaction product and catalyst can be separated very easily and the rhodium is almost perfectly recovered. The catalyst is separated from the reaction product simply by separating the aqueous phase from the organic moieties so that no distillation is required and the resulting aldehydes and alcohols are not subjected to heat treatment. Since the catalyst is only slightly soluble in aldehyde and alcohol, the noble metal is hardly carried by the reaction product. The catalyst system is prepared separately and introduced into the reaction zone or is formed in situ. The first method for reacting the starting materials (rhodium or rhodium compound, water soluble phosphine, carbon monoxide and hydrogen) requires special equipment and additionally the aqueous solution of the reaction product has to be transferred to the reactor. Therefore, the second method, i.e. in situ preparation of the catalyst system in the hydroformylation reactor, proved to be more advantageous. In the latter process, a mixture of rhodium, rhodium oxide or an inorganic rhodium salt, a water-soluble phosphine and water (a solvent, is treated with carbon monoxide and hydrogen at the usual temperature and pressure for the hydroformylation reaction. The disadvantage of rhodium and rhodium oxides is They react only when water-soluble inorganic rhodium salts (eg rhodium chloride or rhodium sulfate) are used only in exceptional cases due to their corrosive action .Rhodium salts soluble in organic solvents may be used instead of water soluble rhodium salts. therefore, rhodium losses should be taken into account in the pre-reaction reaction, since the rhodium, together with the aldehyde formed, is removed from the reactor as long as the organic solvent contains precious metal. SUMMARY OF THE INVENTION It is an object of the present invention to provide a process for the preform formation of a catalyst system consisting of a rhodiura complex compound and a water soluble phosphine in a hydroformylation reactor while eliminating corrosion, precious metal loss and disproportionately long reaction time. The present invention relates to a process for the preparation of aldehydes by reacting olefinically unsaturated compounds, carbon monoxide and hydrogen, at a temperature of 20-150 ° C and a pressure of 0.1-20 MPa in a liquid phase with water and a water-soluble rhodium complex as catalyst. complex compound from a rhodium salt, dissolved in an aliphatic, cycloaliphatic or aromatic hydrocarbon, with a carbon monoxide and hydrogen, before use in the hydroformylation reaction, by reaction with carbon monoxide and hydrogen at 0.1-1.8 MPa and 5-100 ° C. the reaction being carried out in the presence of an aqueous solution of a water-soluble triarylphosphine or after the reaction of the previously prepared rhodium complex compound. Surprisingly, it has been found that under the reaction conditions of the present invention, the active catalyst system EN 202467 Β is formed within a few hours. Although the central atom and the ligands are located in different phases of the biphasic heterogeneous system, the reduction of rhodium and its migration from the organic solvent to the aqueous phase occurs at a satisfactory rate. The carbon monoxide / hydrogen mixture acts as a reducing agent against rhodium, especially water-soluble arylphosphines dissolved in the aqueous phase. These are oxidized to pentavalent phosphorus compounds which do not form complex compounds with catalytic activity with rhodium and are lost as ligands. Therefore, it is expedient to add the aqueous solution of the substituted arylphosphine to the organic phase after the reaction of the rhodium salt, carbon monoxide and hydrogen. The catalyst system is prepared using rhodium salts of organic acids having from 2 to 18 carbon atoms. For this purpose, mono- or polyvalent, linear or branched acids can be used. Saturated or unsaturated aliphatic carboxylic acids and aromatic carboxylic acids can be used. The salts may be prepared by treating the aqueous rhodium salt solution [e.g. rhodium (III) nitrate or rhodium (III) sulfate) is reacted with an aqueous solution of the salt of the organic acid or reacted with rhodium oxide or rhodium oxide hydrate with the free acid. Particularly preferred compounds of the present invention are salts of rhodium with C2-C10 saturated monocarboxylic acids. Thus, acetic acid, propionic acid, n-butyric acid, isobutyric acid, pentanoic acid, hexanoic acid or 2-ethylhexanoic acid are particularly preferably used as acid for salt formation. Generally, no separate purification step is required after the salts have been prepared. In most cases, the reaction product can be directly incorporated in the organic solvent, which is then reacted with carbon monoxide and hydrogen. Organic solvents include aliphatic, cycloaliphatic or aromatic hydrocarbons. There are no special requirements for the physical properties of hydrocarbons. Naturally, hydrocarbons containing impurities which deactivate the catalytic action of rhodium cannot be used in our process. The concentration of rhodium in the hydrocarbon is not a decisive factor; medium concentration solutions are preferred and solutions having a rhodium concentration of at least 3000 mg / L are preferred. There is no need to use a single hydrocarbon, but mixtures of different hydrocarbons can be used as a solvent for rhodium εό. Particularly preferred are pentane, hexane, naphtha, crude oil, toluene or xylenes. The rhodium salt dissolved in the hydrocarbon is treated with carbon monoxide and hydrogen to convert the catalytic activity form in the step. The composition of the CO / H2 mixture can be varied within wide limits. Mixtures of gas rich in carbon monoxide and hydrogen may be used. Generally, however, carbon monoxide and hydrogen will be present in an amount of about. Mixtures of gas containing 1: 1 can be used which have the same composition as the one used in the subsequent hydroformylation reaction. The reaction of rhodium can be carried out at 50-100 ° C and a pressure of 0.1-1.8 MPa. Preferably, temperatures of 60 to 90 ° C and 0.2 to 0.5 MPa are employed; these reaction conditions ensure optimum reaction. The reaction product forms a rhodium hydrocarbonyl. According to the solubility conditions, the primary rhodiurocarbonyl compound migrates to an aqueous solution of water-soluble triarylphosphine and is converted to a rhodium-phosphine complex. The term "water-soluble triaryl phosphines" refers to water-soluble compounds corresponding to the formula (I) because of the presence of one or more sulfonate or carboxylate groups in the molecule. Ar ¹ , Ar ² and Ar ³ are phenyl or naphthyl; Y ¹ , Y ² and Y ³ are straight or branched C 1 -C 4 alkyl or alkoxy, halogen, hydroxy, cyano or nitro or -NR ¹ R ² wherein R ¹ and R ² each independently represents a straight or branched C 1 -C 4 alkyl group; X ¹ , X ² and X ³ are carboxylate (COO * -) and / or sulfonate (SO 3 * -); mi, m2 and m ₃ may be the same or different and are 0, 1, 2 or 3 with the proviso that at least one of m, m2 and m ₃ is 1, 2 or 3; ni, Π2 and n ₃ are identical or different and is 0, 1, 2, 3, 4 or 5; M is an alkali metal ion, an equivalent alkaline earth metal or zinc ion, an ammonium ion or a quaternary ammonium ion of the formula -N (R ³ R ⁴ R ⁵ R ⁶ ) *; R ³ , R ⁴ , R ⁵ and R ⁴ are each independently straight or branched alkyl having up to 18 carbon atoms). Preferred compounds of formula I are those wherein M is a quaternary ammonium group of the formula -N (R ³ , R ⁴ , R ⁵ R ⁶ ) wherein ^{three of} R ³ , R ⁴ , R ⁵ and R ⁶ are C 1 -C 4 and a fourth C 1 -C 18 alkyl group. Preferably, water-soluble triarylphosphines of formula I wherein Ar ¹ , Ar ² and Ar ³ are phenyl-65 can be used. Group 202 represents X ¹ , X ² , X ^{3 a} sulfonate or carboxylate residue. Thus, the following compounds of formula (I) are particularly preferred: triphenylphosphine trisodium trisulfonate; ~ triphenylphosphine tri (tetraalkylammonium) -triszulfonát; triphenylphosphine trisodium tricarboxylate. The sulfonated or carboxylated arylphosphine may be a single compound of formula (I) or a mixture of several phosphines which may have different numbers of sulfonic acid or carboxylate groups. Thus, mixtures of triarylphosphine trisulfonic acids and triarylphosphine disulfonic acids are advantageously used. The above sulfonates or carboxylates may also contain different cations. Thus, mixtures of salts derived from different metals and / or containing ammonium and / or quaternary alkyl ammonium ions are advantageously used. The concentration of the water-soluble triarylphosphine in the aqueous solution is suitably adjusted to the value required for the subsequent hydroformylation reaction, i.e., about 10% by weight of the solution. 25-30% by weight. As mentioned above, the phosphine solution can be added to the aqueous rhodium salt solution. However, in order to avoid losses of phosphine, it is often expedient to first prepare the rhodium carbonyl compound and then add the phosphine solution. The progress of the reaction between phosphine and rhodium can be monitored by decreasing rhodium concentration in the organic phase. The reaction is usually complete within 5-8 hours. At this point, rhodium is no longer detectable in the organic phase. At this time, the reaction conditions for the hydroformylation reaction (20-150 ° C and 0.1-20 MPa pressure) can be adjusted and olefin is introduced into the reactor. After pre-formation of the catalyst, the organic solvent remaining in the reactor at the start of the reaction of the olefin with the synthesis gas is removed from the reaction system and this solvent is removed during the reaction product processing. The process of the present invention is quite generally applicable to the hydroformylation of olefinically unsaturated compounds. Particular preference is given to olefins having from 2 to 12 carbon atoms, linear or branched, having a double bond in the end position or in a chain. The process according to the invention is e.g. suitable for hydroformylation of the following olefins: ethylene, propylene, 1-butene, 2-butene, 1-pentene, 2-methyl-1-butene, 4,4-dimethyl-1-nonene, 1-dodecene. C2-C8 linear olefins (e.g., ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene) are preferred. The aqueous catalyst solution preferably has a water-soluble phosphine concentration of 25-30% by weight, particularly 26-28% by weight, and a rhodium concentration of 450-800% by weight ppm, preferably 500-600% by weight. The total pressure of hydrogen and carbon monoxide is from 1 to 200 bar (100 to ² x 10 ⁴ kPa), preferably from 10 to 100 bar (1 to 10 ^{3 to} 10 ⁴ kPa). The composition of the synthesis gas, i.e. the ratio of carbon monoxide to hydrogen, can be varied within wide limits. Preferably, a synthesis gas in which the ratio of carbon monoxide to hydrogen is 1: 1 or slightly less than this value is used. The reaction may be carried out at 20-150 ° C and may be carried out in a continuous or batch operation. The following examples further illustrate the process without limiting the invention to the examples. Example 1 Aqueous solution of triphenylphosphine trisulphonate (about 30% w / w of the solution) and a solution of rhodium 2-ethylhexanoate in toluene (about 10 g / l rhodium in an autoclave mixture at about 80 ° C and 0 ° C). Synthesis gas (CO: H2 = 1: 1) at 4 MPa The migration of the rhodium salt in toluene into the aqueous phase is monitored by analyzing the organic solvent at regular intervals After about 5 hours, the organic phase no longer contains rhodium the rhodium content of the aqueous phase corresponds to the amount of rhodium initially fed. Example 2 A solution of rhodium hexanoate in toluene (rhodium content 5 g / l) was treated with synthesis gas (CO: Hz = 1: 1) in an autoclave with stirring at 70 ° C and 0.7 MPa. After 3 hours, the solution of rhodium compound was ca. An aqueous solution of triphenylphosphine trisulphonate (about 28% w / w of the solution) was added in an amount of 100: 1 P (III): Rh. The mixture was stirred for an additional 1 hour. the total amount has passed from the organic phase to the aqueous phase. HU 202467 Β PATENT CLAIMS A process for the preparation of aldehydes by reacting olefinically unsaturated compounds, ethylene monoxide and hydrogen, at a temperature of 20-150 ° C and a pressure of 0.1-20 MPa in a liquid phase with water and a water-soluble rhodium-containing complex as catalyst. is formed by reaction of an aliphatic, cycloaliphatic or aromatic hydrocarbon of a carboxylic acid with carbon monoxide and hydrogen at a pressure of 0.1-1.8 MPa and 50-100 ° C in the presence of an aqueous solution of triarylphosphine, characterized in that: The complex compound is prepared prior to the hydroformylation reaction, wherein an aqueous solution of the water-soluble triarylphosphine is added during or after the reaction of the rhodium compound with carbon monoxide and hydrogen. 2. A process according to claim 1 wherein the rhodium salt is derived from a saturated C 2 -C 10 monocarboxylic acid. 3. The process according to claim 2, wherein the rhodium salt is rhodium (III) -2-ethylhexanoate. 4. A process according to any one of the preceding claims wherein the rhodium salt is dissolved in pentane, hexane, gasoline, toluene or xylene. 5. A process according to any one of claims 1 to 3, characterized in that a solution having a rhodium concentration of at least 3000 mg / l is used. 6. The process according to any one of claims 1 to 3, wherein the reaction of the rhodium salt with carbon monoxide and hydrogen is carried out at 60-90 ° C and a pressure of 0.2-0.5 MPa. 7. A process according to any one of claims 1 to 3, wherein the water-soluble triarylphosphine is a compound of formula (I) Ar ¹ , Ar ² and Ar ³ are phenyl or naphthyl; Y ¹ , Y ² and Y ³ are straight or branched C 1 -C 4 alkyl or alkoxy, halogen, hydroxy, cyano or nitro, or -NR'R ² wherein R ¹ and R ² each independently represent a linear or branched C 1 -C 4 al ² O ² moiety; X ^1, X ² and X ³ is carboxyl te swept (COO ^-) - and / or szulfonátmaradék (SO * 3); what, mz and m3 may be the same or different? 5 and have a value of 0, 1, 2 or 3, provided that at least ten of us, m 2 and m 3 are 1, 2, or 3; ni, m and n can be the same or different 30 and are 0, 1, 2, 3, 4 or 5; M is an alkali metal ion, equivalent alkaline earth metal or zinc ion ammonium ion, or -N (R ³ R ⁴ R ⁵ R ⁶ ) * 35 quaternary ammonium ions; ^{R3, R4, R5} and ^R6 are independently linear or branched up to 18 carbon atoms].