CA1037488A - Process for preparing tetrahydrofuran - Google Patents
Process for preparing tetrahydrofuranInfo
- Publication number
- CA1037488A CA1037488A CA211,076A CA211076A CA1037488A CA 1037488 A CA1037488 A CA 1037488A CA 211076 A CA211076 A CA 211076A CA 1037488 A CA1037488 A CA 1037488A
- Authority
- CA
- Canada
- Prior art keywords
- silica
- carboxylic acid
- butanediol
- temperature
- catalyst
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Furan Compounds (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A process for preparing tetrahydrofuran which comprises heating a carboxylic acid monoester of 1,4-butanediol in the presence of a dehydroacycloxylation catalyst.
A process for preparing tetrahydrofuran which comprises heating a carboxylic acid monoester of 1,4-butanediol in the presence of a dehydroacycloxylation catalyst.
Description
7~B : ::
This invention relates to a process for preparing tetrahydrofuran which comprises heating a carboxylic acid monoester of 1,4-butanediol in the presence of a dehydro-acyloxylation catalyst.
It is known in the art that tetrahydrofuran may be made by a number of different methods, the more prominent methods are by the catalytic hydrogenation of furan or by the dehydration of 1,4-butanediol.
In practice, the tetrahydrofuran is most often produced by a series of reactions starting with the reaction of formaldehyde and acetylene in the presence of a cuprous acetylide complex to form butynediol. Butynediol is converted on hydroyenation to butanediol. The 1,4-butanediol is con-verted to tetrahydro~uran as indicated boave.
Additionally, tetrahydrofuran is prepared from maleic acid, its esters, maleic anhydride, fumaric acid, its esters, succinic acid, its esters, succinic anhydride, ~ -butyrolactone, or mixtures of these compounds, by hydrogenation over a hydrogenation catalyst.
However, these methods involve considerably expensive equipment and the handling of hazardous materials.
Also, catalysts in some cases may be e~pensive, and in other `
instances may be easily poisoned Tetrahydrofuran is a useful solvent for natur~ and synthetic resins, particularly vinyls. Also, it is used as an intermediate in the manufacture of nylon, 1,4-dichlorobutane and polyurethanes.
It has been discovered that tetrahydrofuran may be inexpensively prepared from a carboxylic acid monoester of 1,4-butanediol by heatin~ it in the presence of a heterogeneous dehydroacyloxylation catalyst. By this method, tetrahydrofuran is produced in essentially quantitative yields. Also, the ' ~ O ~ ~ 8CH-2012 dehydroacyloxylation catalyst of the instant invention is stationary and permanent and therefore may be continually reused~
Another object of t~is invention is to produce tetrahydrofuran from inexpensive starting materials, i.e., propylene, carbon monoxide, hydrogen and oxygen, by way of several intermediate steps.
The dehydroacyloxylation catalysts which may be employed in the practice of this invention are those which promote ring closure and evolution of the carboxylic acid.
In the case of the acetate ester, the catalyst is a de-hydroacetoxylation catalyst. Suitable dehydroacylo~ylation catalystsinclude zeolites, silica, alumina, silica-aluminas, silica-magnesias, acidic clays and t~e like.
The zeolite dehydroacyloxylation catalysts which `; i may be used in the instant invention include the synthetic and natural zeolites, also known as molecular sieves. These zeolites are well kno~n in t~e art and are detailed in Molecular Sieves, Charles ~. ~ersh, Reinhold Publishing -Company, Mew York (1961). Preferably, representative natural zeolites which may be employed in the instant invention include those in Table 3-1, on page 21, of the ~ersh reference ~
while representative molecular sieves include those in Table ;
5-1, on page 54, of the Hersh reference. Ad~tional zeolite catalysts are set forth in Orqanic Catalysts Over Crystalline .
Aluminosilicates, P B Venuto and P S Landis, ~dvances in Catalysis, Vol. 18, pp. 259 to 371 (1968).
The silica-alumina dehydroacyloxylation catalysts which may be used vary in composition from pure silica to pure alumina whereas the silica-magnesias vary in composition from pure silica to predominantly magnesia.
This invention relates to a process for preparing tetrahydrofuran which comprises heating a carboxylic acid monoester of 1,4-butanediol in the presence of a dehydro-acyloxylation catalyst.
It is known in the art that tetrahydrofuran may be made by a number of different methods, the more prominent methods are by the catalytic hydrogenation of furan or by the dehydration of 1,4-butanediol.
In practice, the tetrahydrofuran is most often produced by a series of reactions starting with the reaction of formaldehyde and acetylene in the presence of a cuprous acetylide complex to form butynediol. Butynediol is converted on hydroyenation to butanediol. The 1,4-butanediol is con-verted to tetrahydro~uran as indicated boave.
Additionally, tetrahydrofuran is prepared from maleic acid, its esters, maleic anhydride, fumaric acid, its esters, succinic acid, its esters, succinic anhydride, ~ -butyrolactone, or mixtures of these compounds, by hydrogenation over a hydrogenation catalyst.
However, these methods involve considerably expensive equipment and the handling of hazardous materials.
Also, catalysts in some cases may be e~pensive, and in other `
instances may be easily poisoned Tetrahydrofuran is a useful solvent for natur~ and synthetic resins, particularly vinyls. Also, it is used as an intermediate in the manufacture of nylon, 1,4-dichlorobutane and polyurethanes.
It has been discovered that tetrahydrofuran may be inexpensively prepared from a carboxylic acid monoester of 1,4-butanediol by heatin~ it in the presence of a heterogeneous dehydroacyloxylation catalyst. By this method, tetrahydrofuran is produced in essentially quantitative yields. Also, the ' ~ O ~ ~ 8CH-2012 dehydroacyloxylation catalyst of the instant invention is stationary and permanent and therefore may be continually reused~
Another object of t~is invention is to produce tetrahydrofuran from inexpensive starting materials, i.e., propylene, carbon monoxide, hydrogen and oxygen, by way of several intermediate steps.
The dehydroacyloxylation catalysts which may be employed in the practice of this invention are those which promote ring closure and evolution of the carboxylic acid.
In the case of the acetate ester, the catalyst is a de-hydroacetoxylation catalyst. Suitable dehydroacylo~ylation catalystsinclude zeolites, silica, alumina, silica-aluminas, silica-magnesias, acidic clays and t~e like.
The zeolite dehydroacyloxylation catalysts which `; i may be used in the instant invention include the synthetic and natural zeolites, also known as molecular sieves. These zeolites are well kno~n in t~e art and are detailed in Molecular Sieves, Charles ~. ~ersh, Reinhold Publishing -Company, Mew York (1961). Preferably, representative natural zeolites which may be employed in the instant invention include those in Table 3-1, on page 21, of the ~ersh reference ~
while representative molecular sieves include those in Table ;
5-1, on page 54, of the Hersh reference. Ad~tional zeolite catalysts are set forth in Orqanic Catalysts Over Crystalline .
Aluminosilicates, P B Venuto and P S Landis, ~dvances in Catalysis, Vol. 18, pp. 259 to 371 (1968).
The silica-alumina dehydroacyloxylation catalysts which may be used vary in composition from pure silica to pure alumina whereas the silica-magnesias vary in composition from pure silica to predominantly magnesia.
- 2 - ,~
; :' ~7~ 8CH-2012 The acidic clay dehydroacyloxylation catalysts which may be used in the instant inve~ion include clays containing the minerals kaolinite, halloysite, montmorillonite, illite, quartz, calcite, liminomite, gypsum, muscavite and the like, either in naturally acidic forms or after treatment with acid.
The catalyst is preferably used in the form of a bed through which the reactants are passed.
The carboxylic acid monoesters of 1,4-butanediol which are suitable in the instant invention preferably contain 2 to 8 carbon atoms. A preferred carboxylic acid monoester of 1,4-butanediol is 4-acetoxybutanol. -~
The temperature at which the process can be carried out varies widely. Temperatures ranging from about 125C. to about 300C. are generally adequate although higher temperature~
can be used. Preferably, the reaction is carried out at a temperature of from about 150C. to about 250C. The maximum depends upon destruction of the product, olefin formation occurring under too rigorous conditions.
Although only atmospheric pressure is normally required, it will be of course apparent to those skilled in the art that superatmospheric pressure or subatmospheric pressure may be used where conditions and concentrations so dictate.
The process may be illustrated, taking 4-acetoxy-butanol as an example, by the following equation:
O
HO(CH2)40CCH3 ~ CH2 CH2 + CH3COH
.~ C~ ~CH2 ,, ... ~
In Canadian application Serial No . ~03, a/~ of William E. Smith, filed ~ne ~y, /~ and assigned to the same assignee as the present invention, there is disclosed - . . , . ~ ,, . ,:. : . .. .. : .
~ ~ 8CH-2012 and claimed a process for ma~ing butanediols by reacting propylene, oxygen and a carboxylic acid to produce an allyl carboxylate which is then hydroformylated to produce the mixture of the corresponding aldehydes. Hydrogenation of the mixture produces a mixture of the esters of the corresponding diols. In Canadian application Serial No. 195,892 of William E. Smith, filed March 25, 1974 and assigned to the same assignee as the present invention, there is disclosed and claimed a process wherein the hydrogenation is accomplished concurrently with the hydroformylation reaction. De-esterification of the diol ester mixture produces the desired butanediols which can be separated by distillation.
In carrying out the preparation of tetra~ydro~uran starting ~rom propylene, oxygen and a car~oxylic acid, the procedures disclosed in the above Canadian applications may be used to obtain the carboxylic acid esters of 1,4-butanediol. ;`
These involve ~a) reacting propylene, oxygen and a carboxylic acid to form the corresponding allyl carboxylate; (b) con-verting the allyl carboxylate under hydroformylation-hydrogenation conditions to a mixture comprising the carboxylic acid esters of 1,4-butanediol, 1,2-butanediol and 2-methyl-1,3-propanediol;
(c~ heating the diol esters in the presence of a dehydro-acyloxylation catalyst to form tetrahydrofuran and the carboxylic acid; and (d) isolating the carboxylic acid in a form suitable for recycling to (a).
To varying extents, depending on reaction conditions, the 1,4-butanediol diester is formed in this sequence, either by disproportionation of the monoester (which affords the diester and diol) or by further esterification of the monoester with the carboxylic acid present as a decomposition .. . ..
product.
- 4 - ~
., :,,:, ~` '.,'' ', ~74~ 8CH-2012 Specifically, this overall process for preparing tetrahydrofuran comprises (a) reacting propylene, oxygen and a carboxylic acid in the presence of a catalyst comprising a . :
Group VIII noble metal, or its salts, or its oxide~ or :-mixtures thereof at a temperature sufficiently high to provide ~.
the desired rate of formation of the corresponding allyl carboxylate but below the temperature at which substantial ~ :
deg.radation of khe allyl carboxylate occurs; (b) converting the allyl carboxylate under hydro-formylation-hydrogenation `~
conditions to a mixture comprising the carboxylic acid esters -of 1,4-butanediol, 1,2-butanediol and 2-methyl-1,3-propanediol;
(c) heating said mixture in the presence of a dehydroacyloxy-lation catalyst to convert the 1,4-butanediol monoester present, as well as any diol, to tetrahydrofuran and the carboxyllc acid; and (d) isolating the carboxylic acid in a form suitable or recycling to (a).
More specifically, the process of producing tetra- .
hydrofuran comprises (a) reacting propylene, oxygen and acetic acid in the presence of a catalyst comprising a Group VIII
noble metal, or its salts or its oxides or mixtures thereof at ~:~
a temperature sufficiently high to provide the desired rate of formation of allyl acetate but below the temperature at which -~
substantial degradation of allyl acetate occurs; (b) con~
verting the allyl acetate under hydrogenation-hydroformylation conditions to a mixture comprising 1,4-butanediol monoacetate, 1,4-butanediol diacetate, 1,4-butanediol and the corresponding derivatives of 2-methyl-1,3-propanediol and 1,2-butanediol;
(c) heating said mixture in the presence of a dehydroacetoxy-lation catalyst to convert the monoacetate of l,4-butanediol :
as well as the diol present to tetrahydrofuran and acetic acid; (d) i~olating the acetic acid in a form suitable for recycling to (a) ... ..
The conditions under which the carboxylic acid esters of 1,4-butanediol, 1,2-butanediol and 2-methyl-1,3-propanediol are formed from propylene, oxygen and carboxylic acids by way of intermediate steps are disclosed in Canadian applications discussed above.
The instant process is carried out in the vapor phaseO All of the carboxylic acid monoester is converted directl~ to tetrahydrofuran and the carboxylic acid, the addition of water being unnecessary. The tetrahydrofuran ;
can be easily isolated by distillation. In contrast, the methods in which water is produced or is otherwise present , afford the tetrahydrofuran-water azeotrope, which must be dealt with in another operation to provide anhydrou~ t~tra-hydrouran. ;~
Additionally, if the li~uid phase and strong acid catalyst are used, a side reaction occurs, i.e., the following disproportionation:
o O o ;~
HO(CH2)40CCH3- ~ OH(CH2)40H ~ C~3CO(CH2)40CCH
This process competes with tetrahydrofuran formation.
The diol formed is easily converted to tetrahydrofuran but the diacetate formed is not. Therefore, a considerable excess of `
water must be present to hydrolyze the diacetate to the mono-acetate so it can eliminate acetic acid and form tetrahydro- ;
furan.
The dehydroacyloxylation mixture can be passed over the catalyst in the liquid phase, vapor phase or liquid-vapor phase. Preferably, it is used in the vapor phase.
For most instances, the reaction is carried out by passing a carboxylic acid monoester of 1,4-butanediol through ~ ;
a heated catalyst bed. Thereafter, the product is distilled - ~
,: .
' ' . . '. : . , ' ,. . .,f .. .
~ ~ 8c~-2012 to effect isolation o~ the carboxylic acid and tetrahydro~uran. ;
Well-known techniques of purification of the fractions can be used to obtain the maximum yield of tetrahydrofuran and the carboxylic acid The following examples are set forth to illustrate more clearly the principle and practice of this invention to those s~illed in the art. Unless otherwise specified, where parts or percents are mentioned, they are parts or percents by weight.
Apparatus - A vertical hot tube reactor (16 mm ID x .
70 cm effective length) is constructed from heavy wall glass, with 24/40 male and female joints. Vigreaux points are idented just above the male joint to support catalyst pellets.
Thermocouple leads are fastened into three other Vigreau~
indentations at points along t~e lengt~. Thr~e 4 ~t. x 1 in.
Briskheat glass insulated heating tapes are wound onto the tube, covered with glass wool and glass tape, and connected to separate variable transformers. The tube exit is connected by a gooseneck (also heated) to an efficient condenser and collection vessel. A three necked flask serves as the evaporator, with the reactants added from an additional funnel in a side neck. ~itrogen carrier gas is passed through to provide residence times on the order of 3 to 10 seconds.
Example 1 - The tube reactor described above is charged with 89 grams of silica-alumina catalyst (87% silica -13% alumina, 3/16" x 3/16" pills, Davison Chemical Grade 970) and i9 maintained at 220-250C. while 50.0 grams of a crude oxo product mixture containing, as indicated by ~uantitative glpc analysis, 31.7 grams of 4-acetoxybutanol, 10.2 of 1,4-butanediol diacetate, a very small amount of 1,4-butanediol, and oxo by-products (about 6 grams of acetate derivatives of 2-methyl~1,3-propanediol and 1,2-butanediol) is flash ~74~ 8CH-2012 i evaporated and passed through over one ~our. Quantitative glpc analysis (propionic acid internal standard) of the effluent shows that no 4-acetoxybutanol remains unconverted, and that - 17.3 grams of tetrahydrofuran (100% yield based on the 4-acetoxybutanol initially present) and 17.6 grams of acetic acid have been collected. The 1,4-butanediol diacetate ard ! OXO by-products pass through the tube essentially unchanged.
Example 2 - A 50.0 gram portion of the same crude oxo product mixture described in Example 1 is passed th~ ugh the tube containing 85 grams of silica-magnesia catalyst ~70%
silica - 30% magnesia, 3/16" x 3/16" pills, Davison Chemical), again at 220-2S0 C. and over a one hour period. The results, as indicated by quantitative glpc analysis of the eEfluent, are substantially the same as in Example 1 - 16.3 grams of tetrahydrofuran (94% yield) and 16.5 grams of acetic acid ;
are collected.
Example 3 - The tube reactor is charged with 110 ' grams of alumina catalyst (1/8" pellets, ~Iarshaw Al-0104T), is which/subsequently subjected to pretreatment at 200C. with 50O/o aqueous acetic acid. Then 50.0 gr~ s of a crude oxo product mixture containing, as indicated by quantitative glpc analysis, 24.3 grams of 4-acetoxybutanol, 8.2 grams of 1,4-butanediol diacetate, and oxo by-products (about 5 grams of
; :' ~7~ 8CH-2012 The acidic clay dehydroacyloxylation catalysts which may be used in the instant inve~ion include clays containing the minerals kaolinite, halloysite, montmorillonite, illite, quartz, calcite, liminomite, gypsum, muscavite and the like, either in naturally acidic forms or after treatment with acid.
The catalyst is preferably used in the form of a bed through which the reactants are passed.
The carboxylic acid monoesters of 1,4-butanediol which are suitable in the instant invention preferably contain 2 to 8 carbon atoms. A preferred carboxylic acid monoester of 1,4-butanediol is 4-acetoxybutanol. -~
The temperature at which the process can be carried out varies widely. Temperatures ranging from about 125C. to about 300C. are generally adequate although higher temperature~
can be used. Preferably, the reaction is carried out at a temperature of from about 150C. to about 250C. The maximum depends upon destruction of the product, olefin formation occurring under too rigorous conditions.
Although only atmospheric pressure is normally required, it will be of course apparent to those skilled in the art that superatmospheric pressure or subatmospheric pressure may be used where conditions and concentrations so dictate.
The process may be illustrated, taking 4-acetoxy-butanol as an example, by the following equation:
O
HO(CH2)40CCH3 ~ CH2 CH2 + CH3COH
.~ C~ ~CH2 ,, ... ~
In Canadian application Serial No . ~03, a/~ of William E. Smith, filed ~ne ~y, /~ and assigned to the same assignee as the present invention, there is disclosed - . . , . ~ ,, . ,:. : . .. .. : .
~ ~ 8CH-2012 and claimed a process for ma~ing butanediols by reacting propylene, oxygen and a carboxylic acid to produce an allyl carboxylate which is then hydroformylated to produce the mixture of the corresponding aldehydes. Hydrogenation of the mixture produces a mixture of the esters of the corresponding diols. In Canadian application Serial No. 195,892 of William E. Smith, filed March 25, 1974 and assigned to the same assignee as the present invention, there is disclosed and claimed a process wherein the hydrogenation is accomplished concurrently with the hydroformylation reaction. De-esterification of the diol ester mixture produces the desired butanediols which can be separated by distillation.
In carrying out the preparation of tetra~ydro~uran starting ~rom propylene, oxygen and a car~oxylic acid, the procedures disclosed in the above Canadian applications may be used to obtain the carboxylic acid esters of 1,4-butanediol. ;`
These involve ~a) reacting propylene, oxygen and a carboxylic acid to form the corresponding allyl carboxylate; (b) con-verting the allyl carboxylate under hydroformylation-hydrogenation conditions to a mixture comprising the carboxylic acid esters of 1,4-butanediol, 1,2-butanediol and 2-methyl-1,3-propanediol;
(c~ heating the diol esters in the presence of a dehydro-acyloxylation catalyst to form tetrahydrofuran and the carboxylic acid; and (d) isolating the carboxylic acid in a form suitable for recycling to (a).
To varying extents, depending on reaction conditions, the 1,4-butanediol diester is formed in this sequence, either by disproportionation of the monoester (which affords the diester and diol) or by further esterification of the monoester with the carboxylic acid present as a decomposition .. . ..
product.
- 4 - ~
., :,,:, ~` '.,'' ', ~74~ 8CH-2012 Specifically, this overall process for preparing tetrahydrofuran comprises (a) reacting propylene, oxygen and a carboxylic acid in the presence of a catalyst comprising a . :
Group VIII noble metal, or its salts, or its oxide~ or :-mixtures thereof at a temperature sufficiently high to provide ~.
the desired rate of formation of the corresponding allyl carboxylate but below the temperature at which substantial ~ :
deg.radation of khe allyl carboxylate occurs; (b) converting the allyl carboxylate under hydro-formylation-hydrogenation `~
conditions to a mixture comprising the carboxylic acid esters -of 1,4-butanediol, 1,2-butanediol and 2-methyl-1,3-propanediol;
(c) heating said mixture in the presence of a dehydroacyloxy-lation catalyst to convert the 1,4-butanediol monoester present, as well as any diol, to tetrahydrofuran and the carboxyllc acid; and (d) isolating the carboxylic acid in a form suitable or recycling to (a).
More specifically, the process of producing tetra- .
hydrofuran comprises (a) reacting propylene, oxygen and acetic acid in the presence of a catalyst comprising a Group VIII
noble metal, or its salts or its oxides or mixtures thereof at ~:~
a temperature sufficiently high to provide the desired rate of formation of allyl acetate but below the temperature at which -~
substantial degradation of allyl acetate occurs; (b) con~
verting the allyl acetate under hydrogenation-hydroformylation conditions to a mixture comprising 1,4-butanediol monoacetate, 1,4-butanediol diacetate, 1,4-butanediol and the corresponding derivatives of 2-methyl-1,3-propanediol and 1,2-butanediol;
(c) heating said mixture in the presence of a dehydroacetoxy-lation catalyst to convert the monoacetate of l,4-butanediol :
as well as the diol present to tetrahydrofuran and acetic acid; (d) i~olating the acetic acid in a form suitable for recycling to (a) ... ..
The conditions under which the carboxylic acid esters of 1,4-butanediol, 1,2-butanediol and 2-methyl-1,3-propanediol are formed from propylene, oxygen and carboxylic acids by way of intermediate steps are disclosed in Canadian applications discussed above.
The instant process is carried out in the vapor phaseO All of the carboxylic acid monoester is converted directl~ to tetrahydrofuran and the carboxylic acid, the addition of water being unnecessary. The tetrahydrofuran ;
can be easily isolated by distillation. In contrast, the methods in which water is produced or is otherwise present , afford the tetrahydrofuran-water azeotrope, which must be dealt with in another operation to provide anhydrou~ t~tra-hydrouran. ;~
Additionally, if the li~uid phase and strong acid catalyst are used, a side reaction occurs, i.e., the following disproportionation:
o O o ;~
HO(CH2)40CCH3- ~ OH(CH2)40H ~ C~3CO(CH2)40CCH
This process competes with tetrahydrofuran formation.
The diol formed is easily converted to tetrahydrofuran but the diacetate formed is not. Therefore, a considerable excess of `
water must be present to hydrolyze the diacetate to the mono-acetate so it can eliminate acetic acid and form tetrahydro- ;
furan.
The dehydroacyloxylation mixture can be passed over the catalyst in the liquid phase, vapor phase or liquid-vapor phase. Preferably, it is used in the vapor phase.
For most instances, the reaction is carried out by passing a carboxylic acid monoester of 1,4-butanediol through ~ ;
a heated catalyst bed. Thereafter, the product is distilled - ~
,: .
' ' . . '. : . , ' ,. . .,f .. .
~ ~ 8c~-2012 to effect isolation o~ the carboxylic acid and tetrahydro~uran. ;
Well-known techniques of purification of the fractions can be used to obtain the maximum yield of tetrahydrofuran and the carboxylic acid The following examples are set forth to illustrate more clearly the principle and practice of this invention to those s~illed in the art. Unless otherwise specified, where parts or percents are mentioned, they are parts or percents by weight.
Apparatus - A vertical hot tube reactor (16 mm ID x .
70 cm effective length) is constructed from heavy wall glass, with 24/40 male and female joints. Vigreaux points are idented just above the male joint to support catalyst pellets.
Thermocouple leads are fastened into three other Vigreau~
indentations at points along t~e lengt~. Thr~e 4 ~t. x 1 in.
Briskheat glass insulated heating tapes are wound onto the tube, covered with glass wool and glass tape, and connected to separate variable transformers. The tube exit is connected by a gooseneck (also heated) to an efficient condenser and collection vessel. A three necked flask serves as the evaporator, with the reactants added from an additional funnel in a side neck. ~itrogen carrier gas is passed through to provide residence times on the order of 3 to 10 seconds.
Example 1 - The tube reactor described above is charged with 89 grams of silica-alumina catalyst (87% silica -13% alumina, 3/16" x 3/16" pills, Davison Chemical Grade 970) and i9 maintained at 220-250C. while 50.0 grams of a crude oxo product mixture containing, as indicated by ~uantitative glpc analysis, 31.7 grams of 4-acetoxybutanol, 10.2 of 1,4-butanediol diacetate, a very small amount of 1,4-butanediol, and oxo by-products (about 6 grams of acetate derivatives of 2-methyl~1,3-propanediol and 1,2-butanediol) is flash ~74~ 8CH-2012 i evaporated and passed through over one ~our. Quantitative glpc analysis (propionic acid internal standard) of the effluent shows that no 4-acetoxybutanol remains unconverted, and that - 17.3 grams of tetrahydrofuran (100% yield based on the 4-acetoxybutanol initially present) and 17.6 grams of acetic acid have been collected. The 1,4-butanediol diacetate ard ! OXO by-products pass through the tube essentially unchanged.
Example 2 - A 50.0 gram portion of the same crude oxo product mixture described in Example 1 is passed th~ ugh the tube containing 85 grams of silica-magnesia catalyst ~70%
silica - 30% magnesia, 3/16" x 3/16" pills, Davison Chemical), again at 220-2S0 C. and over a one hour period. The results, as indicated by quantitative glpc analysis of the eEfluent, are substantially the same as in Example 1 - 16.3 grams of tetrahydrofuran (94% yield) and 16.5 grams of acetic acid ;
are collected.
Example 3 - The tube reactor is charged with 110 ' grams of alumina catalyst (1/8" pellets, ~Iarshaw Al-0104T), is which/subsequently subjected to pretreatment at 200C. with 50O/o aqueous acetic acid. Then 50.0 gr~ s of a crude oxo product mixture containing, as indicated by quantitative glpc analysis, 24.3 grams of 4-acetoxybutanol, 8.2 grams of 1,4-butanediol diacetate, and oxo by-products (about 5 grams of
3-acetoxy-2-methyl propanol, 6 grams of 2-acetoxybutanol, small amounts of the corresponding diacetates and acetic acid) is flash evaporated and passed through at 200-220C over 30 minutes. Quantitative glpc analysis of the effluent shows that no 4-acetoxybutanol remains unconverted and that 12.2 ;
grams of tetrahydrofuran (92% yield based on the 4-acetoxy-butanol) and 17.1 grams of acetic acid have been collected.
~he 1,4-butanediol diacetate passes through the tube unchanged under these conditions.
:, .. : . : . . .............. : , .. .. . . ,, , . :. . . . ..... .. ., . . , ., . ... ,.. - ~ ~ - . ... .
~ xample 4 - The tu~e reactor is char~ed with 91 grams of Linde 13X zeolite (1/8" pellets) and maintained at 250-300 C. Four successive 50 gram portions of 4-acetoxybutanol (containing minor amounts of the disproportionation products 1,4-butanediol and 1,4-butanediol diacetate) are passed through over 30 minute periods. The individual effluents are subjected to ~uantitative glpc analysis; the results are summarized in Table I.
Example 5 - A miniplant is constructed and operated for the production of tetrahydrofuran from propylene via the disclosed cyclic process. An 8 ft. x 1 in. diameter stainless steel tube is charged with one liter (lO00 grams) of ca~alyst com~osed o~ alumina impregnated with palladlum (0.3%) and potassium acetate (3%). The reactor temperature is maintained at 180C. (circulating oil jac~et) while a mixture per hour of 2000 grams of propylene, 600 grams of acetic acid, 170 grams of oxygen and 900 grams of water is passed through. The output per hour is a mixture of about 960 grams of allyl acetate and 1050 grams of water, in addition to 18 grams of carbon dioxide and t~e excess propylene and~oxygen, which are recycled. The allyl acetate phase, which contains about 0.1% acetic acid, is separated and used directly in the second stage of the process.
A two liter stirred autoclave heated at 125C. is pressurized wit~ 3000 psi of 2:1thydrogen/carbon monoxide and charged with a mixture of 400 grams of the allyl acetate, 8.0 grams of cobalt octacarbonyl and 400 ml. o~ benzene. ~n exo-thermic reaction and gas uptake ensue. ~fter 15 minutes at 125-145 C., the product mixture is pumped from the autoclave, cooled and vented. It is then decobalted by heatin~ at 110C.
for lO minutes in a closed ~essel, the addition of acetic acid being unnecessary because of its presence as a decomposition product. (The cobaltous acetate w~ich forms is iltered off _ g _ ~ ~ ~ 8CH-2012 and transformed to cobalt octacarbonyl by subjection to hydrogen/carbon monoxide at elevated temperature and pressure ([160 C., 3000 Psl ). The benzene solution is concentrated .. . . .
and the products are flash distilled, affording 474 grams (91% '~
yield~ of oxo aldehydes containing minor amounts of the butanediol acetate compounds. A glpc analysis indicates the presence of 4-acetoxybutyraldehyde, 3-acetoxy-2-methylpropion-aldehyde and 2-acetoxybutyraldehyde in 7 : 1.5 : 1.5 ratio.
The aldehyde mixture is combined in a stirred auto-clave with 50 grams of a 13% cobalt on silica catalyst, subjected to 3000 psi of hydrogen, and heated for 30 minutes at 150 C. Reduction to the diol derivatives is complete, in essentially quantitative yield. ~ , After removal of the hydrogenation catal~st ~y filtration, the product mixture is examin~d ~y glpc and ~ound to contain 4-acetoxybutanol, 3-acetoxy-2-methylpropanol and 2-acetoxybutanol, and small amounts of their respective diacetate and diol disproportionation products. ;
The acetate mixture is passed directly through an 8 ft. x 1 in. diameter tube containing one liter of the --~
catalyst described in Example 1, at 220 C. and over a 30 minute period (contact time 3-10 seconds). Distillation of t~e effluent affords 184 grams of tetrahydrofuran (64% yield in the conversion from allyl acetate) and 173 grams of acetic acid (72%). The higher boiling components of the effluent include minor amounts of the respective diol diacetates and the by-product monoacetates, from which acetic acid could be derived in a hydrolysis operation. ~o 4-acetoxybutanol remains unconverted.
The acetic acid produced in the final step is recycled to the propylene oxidation stage for production of allyl acetate.
~0~74~ 8CH-2012 .The process as described is operated semi-continuously to provide tetrahydrofuran at about one pound per .
hour.
It should, of course, be apparent to those skilled in the art that changes may be made in the particular embodiments of the invention described which are within the full inté~ded scope of the invention as de~ined by the appended claims.
-- 11 -- ~, .
grams of tetrahydrofuran (92% yield based on the 4-acetoxy-butanol) and 17.1 grams of acetic acid have been collected.
~he 1,4-butanediol diacetate passes through the tube unchanged under these conditions.
:, .. : . : . . .............. : , .. .. . . ,, , . :. . . . ..... .. ., . . , ., . ... ,.. - ~ ~ - . ... .
~ xample 4 - The tu~e reactor is char~ed with 91 grams of Linde 13X zeolite (1/8" pellets) and maintained at 250-300 C. Four successive 50 gram portions of 4-acetoxybutanol (containing minor amounts of the disproportionation products 1,4-butanediol and 1,4-butanediol diacetate) are passed through over 30 minute periods. The individual effluents are subjected to ~uantitative glpc analysis; the results are summarized in Table I.
Example 5 - A miniplant is constructed and operated for the production of tetrahydrofuran from propylene via the disclosed cyclic process. An 8 ft. x 1 in. diameter stainless steel tube is charged with one liter (lO00 grams) of ca~alyst com~osed o~ alumina impregnated with palladlum (0.3%) and potassium acetate (3%). The reactor temperature is maintained at 180C. (circulating oil jac~et) while a mixture per hour of 2000 grams of propylene, 600 grams of acetic acid, 170 grams of oxygen and 900 grams of water is passed through. The output per hour is a mixture of about 960 grams of allyl acetate and 1050 grams of water, in addition to 18 grams of carbon dioxide and t~e excess propylene and~oxygen, which are recycled. The allyl acetate phase, which contains about 0.1% acetic acid, is separated and used directly in the second stage of the process.
A two liter stirred autoclave heated at 125C. is pressurized wit~ 3000 psi of 2:1thydrogen/carbon monoxide and charged with a mixture of 400 grams of the allyl acetate, 8.0 grams of cobalt octacarbonyl and 400 ml. o~ benzene. ~n exo-thermic reaction and gas uptake ensue. ~fter 15 minutes at 125-145 C., the product mixture is pumped from the autoclave, cooled and vented. It is then decobalted by heatin~ at 110C.
for lO minutes in a closed ~essel, the addition of acetic acid being unnecessary because of its presence as a decomposition product. (The cobaltous acetate w~ich forms is iltered off _ g _ ~ ~ ~ 8CH-2012 and transformed to cobalt octacarbonyl by subjection to hydrogen/carbon monoxide at elevated temperature and pressure ([160 C., 3000 Psl ). The benzene solution is concentrated .. . . .
and the products are flash distilled, affording 474 grams (91% '~
yield~ of oxo aldehydes containing minor amounts of the butanediol acetate compounds. A glpc analysis indicates the presence of 4-acetoxybutyraldehyde, 3-acetoxy-2-methylpropion-aldehyde and 2-acetoxybutyraldehyde in 7 : 1.5 : 1.5 ratio.
The aldehyde mixture is combined in a stirred auto-clave with 50 grams of a 13% cobalt on silica catalyst, subjected to 3000 psi of hydrogen, and heated for 30 minutes at 150 C. Reduction to the diol derivatives is complete, in essentially quantitative yield. ~ , After removal of the hydrogenation catal~st ~y filtration, the product mixture is examin~d ~y glpc and ~ound to contain 4-acetoxybutanol, 3-acetoxy-2-methylpropanol and 2-acetoxybutanol, and small amounts of their respective diacetate and diol disproportionation products. ;
The acetate mixture is passed directly through an 8 ft. x 1 in. diameter tube containing one liter of the --~
catalyst described in Example 1, at 220 C. and over a 30 minute period (contact time 3-10 seconds). Distillation of t~e effluent affords 184 grams of tetrahydrofuran (64% yield in the conversion from allyl acetate) and 173 grams of acetic acid (72%). The higher boiling components of the effluent include minor amounts of the respective diol diacetates and the by-product monoacetates, from which acetic acid could be derived in a hydrolysis operation. ~o 4-acetoxybutanol remains unconverted.
The acetic acid produced in the final step is recycled to the propylene oxidation stage for production of allyl acetate.
~0~74~ 8CH-2012 .The process as described is operated semi-continuously to provide tetrahydrofuran at about one pound per .
hour.
It should, of course, be apparent to those skilled in the art that changes may be made in the particular embodiments of the invention described which are within the full inté~ded scope of the invention as de~ined by the appended claims.
-- 11 -- ~, .
Claims (10)
1. A process for preparing tetrahydrofuran which comprises heating a carboxylic acid monoester of 1,4-butanediol in the vapor phase in the presence of a dehydroacyloxylation catalyst selected from the group consisting of natural zeolites, synthetic zeolites, acidic clays, alumina, silica, silica-alumina, and silica-magnesia under substantially anhydrous conditions.
2. The process of claim 1 in which the carboxylic acid monoester of 1,4-butanediol is 4-acetoxybutanol.
3. The process of claim 1 or 2 when carried out at a temperature in the range of about 125°C to about 300°C.
4. The process of claim 2 when carried out at a temperature in the range of about 150°C to about 250°C.
5. The process of claims 1, 2 or 4 wherein said dehydroacyloxylation catalyst is selected from the group consisting of alumina, silica, silica-alumina and silica-magnesia.
6. A process for preparing tetrahydrofuran which comprises the steps of (a) reacting propylene, oxygen and a carboxylic acid to form the corresponding allyl carboxylate;
(b) converting the allyl carboxylate under hydro-formylation-hydrogenation conditions to a mixture comprising the carboxylic acid esters of 1,4-butanediol, 1,2-butanediol and 2-methyl-1, 3-propanediol;
(c) heating the diol esters in the presence of a dehydroacyloxylation catalyst selected from the group consisting of zeolites, silica, alumina, silica-aluminas, silica-magnesias and acidic clays to form tetrahydrofuran and the carboxylic acid; and (d) isolating the carboxylic acid in a form suitable for recycling to (a)
(b) converting the allyl carboxylate under hydro-formylation-hydrogenation conditions to a mixture comprising the carboxylic acid esters of 1,4-butanediol, 1,2-butanediol and 2-methyl-1, 3-propanediol;
(c) heating the diol esters in the presence of a dehydroacyloxylation catalyst selected from the group consisting of zeolites, silica, alumina, silica-aluminas, silica-magnesias and acidic clays to form tetrahydrofuran and the carboxylic acid; and (d) isolating the carboxylic acid in a form suitable for recycling to (a)
7. The process of claim 6 wherein said propylene, oxygen and a carboxylic acid are reacted in the presence of a catalyst comprising a Group VIII noble metal, or its oxides or mixtures thereof at a temperature sufficiently high to provide the desired rate of formation of the corresponding allyl carboxylate but below the temperature at which substantial degradation of the allyl carboxylate occurs.
8. The process of claim 6 wherein said carboxylic acid is acetic acid, and wherein said propylene, oxygen and acetic acid are reacted in the presence of a catalyst comprising a Group VIII noble metal, or its salts or its oxides or mixtures thereof at a temperature sufficiently high to provide the desired rate of formation of allyl acetate but below the temperature at which substantial degradation of allyl acetate occurs.
9. The process of claim 6, 7 or 8 wherein step (c) is carried out at a temperature in the range of about 125°C to about 300°C.
10. The process of claim 6, 7 or 8 wherein step (c) is carried out at a temperature in the range of about 150°C to about 250°C.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US42085173A | 1973-12-03 | 1973-12-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1037488A true CA1037488A (en) | 1978-08-29 |
Family
ID=23668093
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA211,076A Expired CA1037488A (en) | 1973-12-03 | 1974-10-09 | Process for preparing tetrahydrofuran |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1037488A (en) |
-
1974
- 1974-10-09 CA CA211,076A patent/CA1037488A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4652685A (en) | Hydrogenation of lactones to glycols | |
| KR910008935B1 (en) | Process for the production of butane 1,4-diol | |
| US4032458A (en) | Production of 1,4-butanediol | |
| JP5124366B2 (en) | Process for producing 1,6-hexanediol having a purity exceeding 99% | |
| CA1048550A (en) | Process for preparing allylic alcohols | |
| EP0046983A1 (en) | Process for continuously preparing ethylene glycol | |
| KR20010032097A (en) | Method for Producing 1,6-Hexanediol and 6-Hydroxycaproic Acid or Their Esters | |
| US4172961A (en) | Production of 1,4-butanediol | |
| US3948986A (en) | Alpha-hydroxy or alkoxy acid preparation | |
| US4005113A (en) | Multi-step process for preparation of tetrahydrofuran starting from propylene, oxygen and a carboxylic acid | |
| KR20010042926A (en) | Method for Producing Mixtures of 1,4-Butanediol, Tetrahydrofuran and γ-Butyrolactone | |
| US4005112A (en) | Multistep method for preparation of tetrahydrofuran starting from propylene, oxygen and a carboxylic acid | |
| KR100552357B1 (en) | Method for producing 1,4-butanediol | |
| US4010171A (en) | Process for preparing tetrahydrofuran | |
| US6838577B2 (en) | Processes for the manufacture of lactones | |
| US4124600A (en) | Preparation of tetrahydrofuran | |
| US4011244A (en) | Process for preparing tetrahydrofuran | |
| CA1037488A (en) | Process for preparing tetrahydrofuran | |
| KR830002564B1 (en) | Method for preparing butyrolactone | |
| US3981931A (en) | Diols by transesterification using magnesia catalysts | |
| CA1048534A (en) | Process for preparing allylic esters of carboxylic acids and allylic alcohols | |
| CA1037486A (en) | Process for preparing tetrahydrofuran | |
| CA1037487A (en) | Process for preparing tetrahydrofuran | |
| US4475004A (en) | Preparation of alkanediols | |
| DE2461922A1 (en) | Tetrahydrofuran prodn - by catalytic gas phase dehydration of 1,4-butanediol |