DE2504231A1 - Allylic esters and alcohols prodn - by oxidn and esterification of olefins with acids and conversion of esters to butanediol, then methanolysis - Google Patents

Abstract

Allylic esters and allylic alcohols are prepared by reacting a lower alkyl carboxylate, water and the corresp. carboxylic acid and alcohol with an olefin having an allylic C-H bond, and with oxygen in the presence of an oxidation catalyst and opt. an acid cocatalyst. Allyl acetate (produced from methyl acetate, acetic acid, CH3OH, water, propylene and O2) may be subjected to hydroformylation-hydrogenation to give a mixt. of monoacetates of 1,4- and 1,2-butanediols, 2-methyl-1, 3-propanediol and the corresp. dio and diacetate disproportionation products; this mixt. de-esterified (methanolysis) to give methyl acetate (recycled) and butanediols (products). Allyl acetate is used to make polymers, plasticisers etc. and allyl alcohol to make plasticisers and other org. chemicals.

Description

Process for the preparation of allyl esters of carboxylic acids and allyl alcohols The invention relates to a process for the preparation of allyl esters from carboxylic acids and allyl alcohols, which are the reaction of a mixture of a lower alkyl carboxylic acid ester, Water and the corresponding carboxylic acid and alcohol with an olefin, which contains an allylic carbon-hydrogen bond and oxygen in the presence a catalyst system composed of an oxidation catalyst and an acidic co-catalyst includes. The invention also relates to an improved method of manufacture of butanediol.

Allyl esters of carboxylic acids are already different according to a number Process has been established. A useful process for making Allyl acetate consists, for example, of bringing propylene into contact with a palladium catalyst in the presence of oxygen and acetic acid. This procedure is for example in U.S. Patents 3,190,912, 3,275,607 and 3,670,014 and in the South African U.S. Patent 701,077. Allyl acetate is used as an intermediate for manufacturing of polymers, plasticizers and other valuable materials.

The previously known routes that lead to the allyl alcohols are significantly different from the route described above. Allyl alcohol is an example generally by hydrolysis of allyl chloride, by rearrangement of propylene oxide and made by the dehydration of propylene glycol. It is used as an intermediate used in the manufacture of plasticizers and other organic chemicals.

Butanediol is already available after a number of different processes has been produced, which in our own earlier patent applications (A) P 24 25 653.9 and (B) P 24 25 844.4 are summarized.

The disclosure content of these two own earlier patent applications A and B are incorporated into the present application by this reference.

It has been found that allyl esters of carboxylic acids and allyl alcohols can be prepared by a new process in which a mixture of a lower alkyl carboxylic acid ester, water and the corresponding carboxylic acid and alcohol with an olefin having an allyl carbon-hydrogen bond and Oxygen in the presence of a catalyst system composed of an oxidation catalyst and optionally an acidic cocatalyst is used.

As described above, a useful method for the preparation of allyl esters from carboxylic acids consists in the reaction of the appropriate olefin and the carboxylic acid under oxidizing conditions, as illustrated for the case of the allyl acetate by Equation 1 below: If the allyl carboxylate produced in this way is used in a subsequent process which involves the liberation of the carboxylic acid moiety as part of another ester, then this ester can be hydrolyzed by known methods (equation 2) and gives the carboxylic acid for return to the original oxidation reaction.

However, as indicated in equation 2, hydrolysis is an equilibrium process, wherein the isolation of the carboxylic acid repeated equilibrium adjustments and Requires distillation and is therefore inconvenient.

It has now been found that recycling is more effective can be carried out by subjecting the alkyl carboxylate to hydrolysis and the hydrolyzing mixture itself (which contains the carboxylic acid, alcohol, water and unreacted ester, preferably in equilibrium, contains) directly in the oxidation stage is used. The present alcohol and ester do not cause any adverse Effect on the procedure; rather, they pass the reaction and are unchanged can be used for recycling or in a subsequent stage. By using an acidic co-catalyst can do much more to complete the ester hydrolysis be brought and in competition with the oxidation reaction leads this makes the process more economical.

The joint use of an acidic co-catalyst and a higher temperature leads to the formation of substantial amounts of the allyl alcohols, primarily due to the transesterification process described in equation 3 in the event that allyl alcohol is produced from allyl acetate by methanolysis.

The lower alkyl carboxylate esters which can find use in the present invention are illustrated by the following formula: wherein R1 and R2 can contain 1 to about 8 carbon atoms.

The preferred lower alkyl carboxylate ester is methyl acetate.

The olefins that can be used in the present invention are those that have an allyl carbon-hydrogen bond as represented by the following structural formula: wherein R1, R2 and R3 are independently selected from the group consisting of hydrogen, alkyl with 1 to 8 carbon atoms, aryl with 6 to 10 carbon atoms, aralkyl with 7 to 10 carbon atoms and the radical -CHR4R5, in which R4 and R5 are hydrogen, alkyl with Represent 1 to 8 carbon atoms, aryl of 6 to 10 carbon atoms and aralkyl of 7 to 10 carbon atoms.

Preferred olefins are propylene and isobutylene.

The catalyst system of the present invention comprises an oxidation catalyst and optionally an acidic cocatalyst.

The oxidation component of the catalyst can be selected from the group consisting of a Group VIII noble metal or its salts or its oxides or mixtures thereof. Specific examples of such catalysts include metals such as palladium, ruthenium, rhodium, platinum, osmium and iridium as well as oxides and salts such as palladium-II-propionate> palladium-II-benzoate, palladium-II-chloride, palladium-II-bromide, Palladium II oxides etc., ruthenium acetate etc., rhodium acetate etc., platinum II benzoate, Platinum dichloride, platinum oxide, etc., iridium chloride, etc.

and the like, as well as mixtures thereof.

The preferred oxidation catalyst is a mixture of the noble metal of Group VIII and its salts. A preferred oxidation catalyst is one Mixture of palladium and palladium-II-acetate.

The acidic cocatalyst can be an acidic support material such as aluminum oxide or silica or the like, or it may be added in smaller amounts be more active substance.

A promoter can be added to the catalyst system, which the Activity and selectivity influenced. Among the preferred promoters are the alkali metal and alkaline earth metal carboxylates, the transition metals, their salts, To name gold or copper.

The catalyst can be made by a number of different methods getting produced. For example, a neutral carrier such as carbon or an acidic carrier such as alumina with a palladium acetylacetonate solution impregnated in benzene and dried. The material obtained is then with a solution of Potassium acetate impregnated in water and dried. The catalyst is then treated with propylene, which converts the palladium into the metallic Condition reduced. The catalyst obtained in this way contains palladium metal and potassium acetate in a ratio of about 1:10 parts.

Varying amounts of the catalyst can be used within the scope of the present Invention can be used. Quantities as low as about 0.1 based on the weight of the Carrier, have been shown to be effective.

The working temperature is in the range from about 1000C to about 2000C. For optimal production of the allyl ester, the temperature is in the range of about 125 ° C to about 1600C. At higher temperatures, substantial amounts of allyl alcohol become generated.

The working pressure ranges from about atmospheric pressure to about 10.5 kg / cm (150 psi). Slightly higher or lower temperatures and pressures can however, can also be used in the context of the present invention.

The oxygen used in the present process can be used in pure elemental form or in a mixture with inert gases, for example in the form of Air, can be used. However, it is preferred to use concentrated oxygen to work.

The olefin used in the present process is in pure form or in a mixture with inert compounds, such as with saturated hydrocarbons, used.

In practicing allyl ester formation of the present invention For example, in the case of allyl acetate, a mixture of methyl acetate, water, Acetic acid and methanol and propoles together with oxygen through a bed of Catalyst in a tubular reactor at temperatures from about 1000C to about 160 ° C and a pressure of about 5.6 kg / cm² (80 psi). To leaving the reaction zone, the products are condensed and it becomes a two-phase mixture educated. The upper phase consists of a mixture of in this case methyl acetate, Allyl acetate and methanol. The lower phase consists mainly of water and methanol with a small amount of allyl acetate.

Traces of allyl alcohol are present in both phases. The direct one Distillation of the mixture provides the methanol and methyl acetate for recycle and leaves a two-phase mixture of allyl acetate and water. The allyl acetate phase is decanted in a suitable form for further use.

The amount of allyl alcohol produced can be increased considerably by increasing the temperature and the activity of the hydrolysis-methanolysis component of the catalyst. The alkyl carbolate ester hydrolysis mixture (derived for example of methyl acetate) can be supplemented with additional carboxylic acid (for example Acetic acid) to achieve equally satisfactory results.

The present invention also relates to an improved overall process for the production of butanediol from propylene, which is based on the hydrolysis-oxidation sequence described above and is given in the following equations 4 to 6: H20 ö (4) CH2 = CHCH3 + CH COCH + 1/2 0 11 CH - (2ydrolyzate) 2 2 CHCH2 ° CCH3 + CH3oH 0 0 (6) HO (CH2) 40CCH3 + CH30H> HO (CH2) 4oH + CH3COCH3 (+ Isomers) (+ Isomers) (+ isomers) The methyl acetate formed in the methanolysis reaction (equation 6) can be returned to the hydrolysis-oxidation stage (equation 4). The methyl acetate is preferably isolated and recycled as an azeotropic product together with methanol.

In particular, the improved method for the production of Butanediol the following process steps: (a) Reaction of propylene and a Mixture of methyl acetate, water, acetic acid and methanol with oxygen in the presence a catalyst system comprising an oxidation catalyst and an acidic co-catalyst to form allyl acetate; (b) Conversion of the allyl acetate under hydroformylation-hydrogenation conditions in a mixture containing the monoacetate esters of 1,4-butanediol and 2-methyl-1,3-propanediol and 1,2-butanediol and their corresponding diol and diacetate disproportionation products includes; (c) Deesterification of the mixture of the acetate esters of butanediols thus produced under methanolysis conditions to produce the corresponding butanediols and from Methyl acetate; (d) Isolation of the methyl acetate from the butanediols in a suitable Form for use in step (a).

The Methyl acetate hydrolysis mixture can be supplemented with varying proportions of acetic acid.

In our own earlier patent application u9) P 24 25 653.9 is a method for the production of butanediols by reacting propylene, oxygen and a carboxylic acid to produce an allyl carboxylate which is then hydroformylated is disclosed and claimed to give a mixture of the corresponding aldehydes. Hydrogenation of the mixture gives a mixture of the esters of the corresponding diols. In our own earlier patent application (B) P 24 25 844.4, a method is disclosed and claimed in which the hydrogenation is carried out simultaneously with the hydroformylation reaction carried out will. De-esterification of the diol ester mixture gives the desired butanediols, which can be separated by distillation. The disclosure content of these aforementioned our own earlier patent applications (A) and (B) are incorporated by reference in the present application included.

The process for converting the allyl acetate under hydroformylation-hydrogenation conditions in a mixture containing the monoacetate esters of 1,4-butanediol, 2-methyl-1,3-propanediol and 1,2-butanediol and their corresponding diol and diacetate disproportionation products i.e., step (b) of the overall process for making 1,4-butanediol in our own aforementioned earlier patent applications (A) and (B) and described this process is also incorporated into the present application by this reference recorded.

The methanolysis conditions used in step (c) are detailed in our own older patent application (C) P 24 25 761.2 as well as our own older one Patent application (D) P 24 25 878.4 described. The registration (C) describes this the alcoholysis using a basic catalyst while the application (D) describes alcoholysis in the presence of an acidic cation exchange material. The disclosure content of the aforementioned own earlier patent applications (C) and (P) is incorporated into the present application by this reference.

The following examples serve to explain the principle in more detail and the practice of the present invention. Unless expressly is stated otherwise, the parts or percentages are given by parts or percentages by weight.

Example 1 A stainless steel tube 2.44 in length 8 ft. x 1 inch in diameter was charged with 1 liter (1000 g) of alumina catalyst (3.2 mm (1/8 inch) pellets, Harshaw A1-1802-E 1/8) filled and at temperature kept at 2500C, while a mixture of 910 g of methyl acetate-methanol azeotropic per hour Mixture (composed of 740 g of methyl acetate and 170 g of methanol) and 900 g Water at a pressure 2 of 5.6 kg / cm (80 psi) was passed through. According to the quantitative glpc analysis, the outlet contained 282 g of acetic acid, 320 g of methanol, 392 g of methyl acetate and 815 g of water per hour (the composition was after a second pass essentially the same, showing that equilibrium was reached).

These results show that under these conditions, equation 6 K has a value of 0.2.

The hydrolyzate was cooled to about 150 0C and per hour with 2000 g propylene and 170 g oxygen mixed. The obtained mixture became direct through a second tube with a length of 2.44 m and a diameter of 2.54 m cm passed, contain 1 liter of coal particles with a size of 4 to 8 mesh, those with palladium (0.3%) and. Potassium acetate (3%) were impregnated and which at 160 C and under a pressure of 5.6 kg / cm2 (80 psi). The output per hour from this oxidation zone was a mixture which after cooling off consisted of two liquid phases and according to the quantitative glpc analysis of 355 g not converted methyl acetate (48% recovery), 493 g Allyl acetate (95% yield based on 52 $ conversion), 308 g of methanol, one Trace acetic acid and excess water and propylene consisted.

The above procedure was repeated except that in the second tube the carbon through aluminum oxide (Harshaw Al-1802-E 1/8) was replaced. The output consisted of 333 g of methyl acetate (45% recovery), 519 g of allyl acetate (94% yield based on 55% conversion), 326 g of methanol, Traces of allyl alcohol and acetic acid and excess water and propylene combined.

Example 2 The tubular reactors arranged one behind the other were operated as shown in Example 1, with the amount of water used per hour was doubled to 1800 g. Analysis of the condensed phase showed that per hour 229 g of methyl acetate (31% conversion), 644 g of allyl acetate (93% Yield based on 69% conversion) and 380 g of methanol were obtained if a coal carrier was used in the second tube. The replacement of coal due to aluminum oxide, 215 g of methyl acetate (29% not converted), 673 g of allyl acetate (95% yield due to 71% conversion) and 375 g of methanol was obtained.

Example 3 The tubular reactors arranged one behind the other were operated as in Example 1, instead of the methyl acetate-methanol azeotropic Mixture 740 g of pure methyl acetate per hour were used in. If the second Tube a carbon carrier was used, the analysis of the condensed phase showed, that per hour 254 g of methyl acetate (34% not converted), 607 g of allyl acetate (92% Yield based on 66% conversion) and 19-1 g of methanol (90% yield) were obtained. The replacement of the coal by Alumina led to the fact that 222 g of methyl acetate (30% not converted), 637 g of allyl acetate per hour (91% yield based on 70% conversion) and 197 g of methanol (88 % Yield).

Example 4 The tubular reactors connected in series were operated as in Example 2, instead of the methyl acetate-methanol azeotropic Mixture per hour 740 g of pure methyl acetate were used. If a carbon carrier analysis of the condensed phases showed that 157 per hour were used g methyl acetate (21% unconverted), 705 g allyl acetate (89% yield, based on to 79% conversion) and 227 g of methanol (90% yield). Of the Replacing the coal with aluminum oxide resulted in 141 g of methyl acetate per hour (19% not converted), 753 g of allyl acetate (93% yield based on an 81% Conversion) and 233 g of methanol (90% yield) were obtained.

Example 5 A stainless steel tube 15.2 cm in length and 6.35 cm mm diameter (6 "x 1/4") was sealed with an acidic ion exchange resin (Dowex 50 W X 8) charged and heated to 140 ° C., 546 g of the methyl acetate-methanol azeotropes per hour Mixture (composed of 444 g methyl acetate and 102 g methanol) and 2,540 g of water at a pressure of 9.8 kg / cm (140 psi) was passed through. the The mixture produced was the equilibrium hydrolyzate (K = 0.2) which was suitable for use in the oxidation stage as described in Example 1 was suitable.

Example 6 A mixture of 740 g of methyl acetate, 170 g of methanol and 900 grams of water was combined with 25 grams of acidified aluminum silicate powder (Filtrol 20) and heated to 67 to 72 0C for one hour. The catalyst was filtered off and left an equilibrium hydrolyzate (K = 0.15) which is suitable for use in the oxidation stage, as described in example 1, was suitable.

Example 7 The tubular reactors connected in series and the General procedures described in Example 1 were used with a Operating temperature in the oxidation zone increased to 180 ° C. The analysis the outlet showed that 167 g of allyl alcohol in addition to 577 g of allyl acetate per hour and collecting 236 g of unreacted methyl acetate.

Example 8 A small scale plant was designed and used for manufacture operated by butanediol from propylene according to the disclosed cyclic process. The reactors connected in series for hydrolysis and oxidation and the basic procedure as described in Example 1 was used for the production of the allyl acetate is used at a rate of about 500 g per hour.

The product stream of allyl acetate, methyl acetate, methanol, water and the acetic acid formed two phases after condensation.

The mixture was directly distilled using a conventional one Distillation column. The methyl acetate and methanol were removed overhead and they left the allyl acetate, water, and a small amount of acetic acid as soil products return. The distillation of the products passing over at the top gave methyl acetate-methanol azeotropes Mixture (suitable for direct recycling into allyl acetate production) and methanol (suitable for use in the butanediol acetate-methanolysis reaction to be described). The allyl acetate-water-acetic acid distillation residue was cooled; the upper Phase, essentially pure allyl acetate, was decanted and placed directly in the used in the next stage of the procedure. The aqueous phase contained about 5% des Allyl acetate, which could be removed by distillation.

A 2 liter stirred autoclave was heated to 1250C, with a Mixture of hydrogen / carbon monoxide in a ratio of 2: 1 up to a pressure of 211 kg / cm² (3000 psi) and with a mixture of 400 g of the allyl acetate, Charged 8.0 g of cobalt octacarbonyl and 400 ml of benzene. It found an exothermic reaction and a gas intake takes place. After 15 minutes at a temperature of 125 to 1450C the product mixture was pumped out of the autoclave, cooled and vented. By It was then heated for 10 minutes in a closed vessel at 110 ° C freed from cobalt, the addition of acetic acid was unnecessary because it was already was present as a decomposition product. (The cobalt (II) acetate which formed was filtered off and converted to the cobalt octacarbonyl by it'at elevated temperature and Pressure (1600C, 211 kg / cm2 (5000 psi)) to a hydrogen / carbon monoxide mixture The benzene solution was concentrated and the products were distilled off and gave 447 g (91% yield) of the oxoaldehydes, which were lesser amounts of the butanediol acetate compounds contained. A glpc analysis showed the presence of 4-acetoxybutyraldehyde, 3-acetoxy-2-methyl-propionaldehyde and 2-acetoxybutyraldehyde in a ratio of 7: 1.5 : 1.5 on.

The aldehyde mixture was in a stirred autoclave with 50 g of one 30% cobalt on silica catalyst combined, and a hydrogen pressure of 70 kg / cm² and heated at 1500C for 30 minutes. The reduction of Diol derivatives took place essentially completely in quantitative yield.

After removal of the hydrogenation catalyst by filtration the product mixture was examined by glpc analysis and found to be 4-acetoxybutanol, 3-acetoxy-2-methylpropanol and 2-acetoxybutanol as well as low Contained amounts of their corresponding diacetate and diol disproportionation products.

The low-boiling components of the hydrogenation mixtures (in the Mainly water, acetic acid and hydrogenation products from methacrolein and Allyl acetate) were distilled off under reduced pressure. Of the Residue was with 500 g of methanol, which contained 2.5 g of sodium hydroxide, in a static mixing tube combined leading to a Goodloe distillation column of 1.22 m long and 2.54 cm (4 ft. x 1 inch) in diameter. The methanolysis reaction took place in a 60 cm long filled part below the feed point. Methyl acetate and most of the excess methanol were stripped overhead and then fractionated and gave the methyl acetate-methanol-azeotropic mixture and pure methanol, both of which were suitable for direct recycle.

According to the glpc analysis, the bottom products contained 241 g 1,4-butanediol (67% yield when converted from allyl acetate), 14 g of 2-methyl-1,3-propanediol (4% yield) and 51 g of 1,2-butanediol (14% yield). The mixture was distilled off and left a residue of partially activated catalyst. Fractionation of the diols through a Goodloe column 1.2 m long and 5.08 cm in diameter (4th ft. x 2 inch) gave the three isomers 1,4-butanediol (boiling point 1440 at 20 mm), 2-methyl-1,3-propanediol (boiling point 1320 at 20 mm) and 1,2-butanediol (boiling point 1210/20 mm).

The process described was operated semi-continuously and provided butanediol at a rate of about 0.45 kg (1 pound) per hour.

Claims (10)

Claims 1. Process for the preparation of allyl esters of carboxylic acids and k <Allyl alcohols, g e k e n n n z e i c h n e t d u r c h the reaction of a mixture from a lower alkyl carboxylic acid ester, water and the corresponding carboxylic acid and alcohol with an olefin having an allyl-carbon-hydrogen bond and oxygen in the presence of a catalyst system which is an oxidation catalyst and optionally contains an acidic cocatalyst. 2. Process for the preparation of allyl acetate, d a d u r c h g e k e n g e i n e t> that propylene, a mixture of methyl acetate, water, Acetic acid and methanol and oxygen in the presence of a catalyst system of a Group VIII noble metal or its oxides or mixtures thereof and an acidic cocatalyst are reacted. 3. Process for the production of allyl alcohol, d a d u r c h g e k Note that propylene, methyl acetate, water, acetic acid and methanol as well as oxygen in the presence of a catalyst system which is a noble metal of Group VIII or its salts or its oxides or mixtures thereof and contains an acidic cocatalyst. 4. Improved Process for the Production of Butanediol, g e k e n n z e i c h n e t d u r c h the following process steps: (a) Implementation of Propylene and a mixture of methyl acetate, water, acetic acid and methanol with Oxygen in the presence of a catalyst system which is an oxidation catalyst and contains an acidic cocatalyst to form allyl acetate; (b) Conversion of the allyl acetate under hydroformylation-hydrogenation conditions to a mixture containing the monoacetate esters of 1,4-butanediol, 2-methyl-1,3-propanediol and 1,2-butanediol and their corresponding diol and diacetate disproportionation products includes; (c) Deesterification of the mixture of acetate esters of the butanediols thus produced under methanolysation conditions to produce the corresponding butanediol and of methyl acetate; (d) Isolation of the methyl acetate from the butanediols and conversion the same into a suitable form for use in step (a). 5. The method according to any one of the preceding claims, d a d u r c it is not noted that the oxidation catalyst is a noble metal Group VIII or its salts or its oxides or mixtures thereof. 6. The method according to any one of the preceding claims, d a d u r c h e k e k e n n n z e i c h n e t> that the acidic co-catalyst is an acidic carrier is. 7. The method according to claim 6, d a d u r c h g e k e n n -z e i c h not that the acidic co-catalyst is aluminum oxide or silicon oxide. 8. The method according to any one of the preceding claims, d a d u r c it is not noted that the acidic co-catalyst is aluminum oxide or Is silicon oxide. 9. The method according to any one of the preceding claims, d a d u r c h e k e k e n n n n e i n e t that the process takes place at a temperature of about 1000C to about 2000C is carried out. 10. The method according to any one of the preceding claims, d a d u r c Note that the temperature is kept between 1600C and 2000C.