U.S. patent application number 09/757247 was filed with the patent office on 2001-08-09 for method and catalyst system for producing aromatic carbonates.
Invention is credited to Johnson, Bruce Fletcher, Shalyaev, Kirill Vladimirovich, Soloveichik, Grigorii Lev, Whisenhunt, Donald Wayne JR..
Application Number | 20010012904 09/757247 |
Document ID | / |
Family ID | 23969010 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010012904 |
Kind Code |
A1 |
Shalyaev, Kirill Vladimirovich ;
et al. |
August 9, 2001 |
Method and catalyst system for producing aromatic carbonates
Abstract
A method and catalyst system for producing aromatic carbonates
from aromatic hydroxy compounds. In one embodiment, the method
includes the step of contacting at least one aromatic hydroxy
compound with oxygen and carbon monoxide in the presence of a
carbonylation catalyst system having catalytic amounts of the
following components: a Group VIII B metal source; a combination of
inorganic co-catalysts including a copper source and at least one
of a titanium source or a zirconium source; an onium chloride
composition; and a base. Alternative embodiments include inorganic
co-catalyst combinations of a lead source and at least one of a
titanium source or a manganese source.
Inventors: |
Shalyaev, Kirill Vladimirovich;
(Clifton Park, NY) ; Soloveichik, Grigorii Lev;
(Latham, NY) ; Johnson, Bruce Fletcher; (Scotia,
NY) ; Whisenhunt, Donald Wayne JR.; (Niskayuna,
NY) |
Correspondence
Address: |
GENERAL ELECTRIC COMPANY
CRD PATENT DOCKET ROOM 4A59
P O BOX 8
BUILDING K 1 SALAMONE
SCHENECTADY
NY
12301
US
|
Family ID: |
23969010 |
Appl. No.: |
09/757247 |
Filed: |
January 10, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09757247 |
Jan 10, 2001 |
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09495539 |
Jan 31, 2000 |
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6207849 |
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Current U.S.
Class: |
558/274 |
Current CPC
Class: |
C07C 68/01 20200101;
C07C 69/96 20130101; C07C 69/96 20130101; C07C 68/01 20200101; C07C
68/01 20200101 |
Class at
Publication: |
558/274 |
International
Class: |
C07C 069/96 |
Claims
What is claimed is:
1. A method of carbonylating an aromatic hydroxy compound, said
method comprising the step of: contacting at least one aromatic
hydroxy compound with oxygen and carbon monoxide in the presence of
a carbonylation catalyst system comprising catalytic amounts of the
following components: a Group VIII B metal source; a combination of
inorganic co-catalysts including a lead source and at least one of
a titanium source or a manganese source; an onium chloride
composition; and a base.
2. The method of claim 1, wherein the Group VIII B metal source is
a palladium source.
3. The method of claim 2, wherein the palladium source is a non-
supported Pd(II) salt or complex.
4. The method of claim 3, wherein the palladium source is
dichloro(1,4-bis(diphenylphosphino)butane) palladium (II).
5. The method of claim 1, wherein the onium chloride composition is
tetrabutylammonium chloride.
6. The method of claim 1, wherein the base is sodium phenoxide.
7. The method of claim 1, wherein the aromatic hydroxy compound is
phenol.
8. The method of claim 1, wherein the combination of inorganic
co-catalysts includes a lead source and a titanium source.
9. The method of claim 1, wherein the combination of inorganic
co-catalysts includes a lead source and a manganese source.
10. A method of carbonylating an aromatic hydroxy compound, said
method comprising the step of: contacting at least one aromatic
hydroxy compound with oxygen and carbon monoxide in the presence of
a carbonylation catalyst system comprising catalytic amounts of the
following components: a Group VIII B metal source; a combination of
inorganic co-catalysts including a copper source and at least one
of a titanium source or a zirconium source; an onium chloride
composition; and a base.
11. The method of claim 10, wherein the Group VIII B metal source
is a palladium source.
12. The method of claim 11, wherein the palladium source is a
non-supported Pd(II) salt or complex.
13. The method of claim 12, wherein the palladium source is
dichloro(1,4-bis(diphenylphosphino)butane) palladium (II).
14. The method of claim 10, wherein the onium chloride composition
is tetrabutylammonium chloride.
15. The method of claim 10, wherein the base is sodium
phenoxide.
16. The method of claim 10, wherein the aromatic hydroxy compound
is phenol.
17. The method of claim 10, wherein the combination of inorganic
co-catalysts includes a copper source and a titanium source.
18. The method of claim 10, wherein the combination of inorganic
co-catalysts includes a copper source and a zirconium source.
19. A carbonylation catalyst system, comprising catalytic amounts
of the following components: a Group VIII B metal source; a
combination of inorganic co-catalysts including a lead source and
at least one of a titanium source or a manganese source; an onium
chloride composition; and a base.
20. The carbonylation catalyst system of claim 19, wherein the
Group VIII B metal source is a palladium source.
21. The carbonylation catalyst system of claim 20, wherein the
palladium source is a non-supported Pd(II) salt or complex.
22. The carbonylation catalyst system of claim 21, wherein the
palladium source is dichloro(1,4-bis(diphenylphosphino)butane)
palladium (II).
23. The carbonylation catalyst system of claim 19, wherein the
onium chloride composition is tetrabutylammonium chloride.
24. The carbonylation catalyst system of claim 19, wherein the base
is sodium phenoxide.
25. The carbonylation catalyst system of claim 19, wherein the
aromatic hydroxy compound is phenol.
26. The carbonylation catalyst system of claim 19, wherein the
combination of inorganic co-catalysts includes a lead source and a
titanium source.
27. The carbonylation catalyst system of claim 19, wherein the
combination of inorganic co-catalysts includes a lead source and a
manganese source.
28. A carbonylation catalyst system, comprising catalytic amounts
of the following components: a Group VIII B metal source; a
combination of inorganic co-catalysts including a copper source and
at least one of a titanium source or a zirconium source; an onium
chloride composition; and a base.
29. The carbonylation catalyst system of claim 28, wherein the
Group VIII B metal source is a palladium source.
30. The carbonylation catalyst system of claim 29, wherein the
palladium source is a non-supported Pd(II) salt or complex.
31. The carbonylation catalyst system of claim 30, wherein the
palladium source is dichloro(1,4-bis(diphenylphosphino)butane)
palladium (II).
32. The carbonylation catalyst system of claim 28, wherein the
onium chloride composition is tetrabutylammonium chloride.
33. The carbonylation catalyst system of claim 28, wherein the base
is sodium phenoxide.
34. The carbonylation catalyst system of claim 28, wherein the
aromatic hydroxy compound is phenol.
35. The carbonylation catalyst system of claim 28, wherein the
combination of inorganic co-catalysts includes a lead source and a
titanium source.
36. The carbonylation catalyst system of claim 28, wherein the
combination of inorganic co-catalysts includes a lead source and a
zirconium source.
Description
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention is directed to a method and catalyst
system for producing aromatic carbonates and, more specifically, to
a method and catalyst system for producing diaryl carbonates
through the carbonylation of aromatic hydroxy compounds.
[0003] 2. Discussion of Related Art
[0004] Aromatic carbonates find utility, inter alia, as
intermediates in the preparation of polycarbonates. For example, a
popular method of polycarbonate preparation is the melt
transesterification of aromatic carbonates with bisphenols. This
method has been shown to be environmentally superior to previously
used methods which employed phosgene, a toxic gas, as a reagent and
chlorinated aliphatic hydrocarbons, such as methylene chloride, as
solvents.
[0005] Various methods for preparing aromatic carbonates have been
previously described in the literature and/or utilized by industry.
A method that has enjoyed substantial popularity in the literature
involves the direct carbonylation of aromatic hydroxy compounds
with carbon monoxide and oxygen. In general, practitioners have
found that the carbonylation reaction requires a rather complex
catalyst system. For example, in U.S. Pat. No. 4,187,242, which is
assigned to the assignee of the present invention, Chalk reports
that a carbonylation catalyst system should contain a Group VIII B
metal, such as ruthenium, rhodium, palladium, osmium, iridium,
platinum, or a complex thereof. Further refinements to the
carbonylation reaction include the identification of organic
co-catalysts, such as terpyridines, phenanthrolines, quinolines and
isoquinolines in U.S. Pat. No. 5,284,964 and the use of certain
halide compounds, such as quaternary ammonium or phosphonium
halides in U.S. Pat. No. 5,399,734, both patents also being
assigned to the assignee of the present invention.
[0006] The economics of the carbonylation process is strongly
dependent on the number of moles of aromatic carbonate produced per
mole of Group VIII B metal utilized (i.e. "catalyst turnover").
Consequently, much work has been directed to the identification of
efficacious catalyst combinations that increase catalyst turnover.
In U.S. Pat. No. 5,231,210, which is also assigned to the present
assignee, Joyce et al. report the use of a cobalt pentadentate
complex as an inorganic co-catalyst ("IOCC"). In U.S. Pat. No.
5,498,789, Takagi et al. report the use of lead as an IOCC. In U.S.
Pat. No. 5,543,547, Iwane et al. report the use of trivalent cerium
as an IOCC. In U.S. Pat. No. 5,726,340, Takagi et al. report the
use of lead and cobalt as a binary IOCC system.
[0007] Carbonylation catalyst literature lauds the effectiveness of
bromide compounds as a halide source in the catalyst system. For
example, in the aforementioned U.S. Pat. No. 5,543,547, Iwane et
al. state the traditional understanding that bromide sources are
the preferred halide sources and that chloride is known to exhibit
low activity. While it is true that bromide has historically
exhibited higher activity, there are drawbacks to using bromide in
the carbonylation reaction. Initially, it is worth noting that
onium bromide compounds are typically expensive compared to, e.g.,
onium chloride compounds. Furthermore, when used to carbonylate
phenol, bromide ion is consumed in the process forming undesirable
brominated byproducts, such as 2- and 4- bromophenols and bromo
diphenylcarbonate. These byproducts must typically be recovered and
recycled, further adding to the investment and operating cost of
the process. However, due to their comparatively low activity,
onium chloride compounds have not traditionally been considered an
economically viable alternative to onium bromide compounds.
[0008] Unfortunately, the literature is not instructive regarding
the role of many catalyst components in the carbonylation reaction
(i.e. the reaction mechanism). Accordingly, meaningful guidance
regarding the identification of effective combinations of catalyst
system components is cursory at best. In this regard, periodic
table groupings have failed to provide guidance in identifying
additional IOCC's. For example, U.S. Pat. No. 5,856,554 provides a
general listing of possible IOCC candidates, yet further analysis
has revealed that many of the members (and combinations of members)
of the recited groups (i.e., Groups IV B and V B) do not
effectively catalyze the carbonylation reaction. Therefore, due to
the lack of guidance in the literature, the identification of
effective carbonylation catalyst systems has become a serendipitous
exercise.
[0009] As the demand for high performance plastics has continued to
grow, new and improved methods of providing product more
economically are needed to supply the market. In this context,
various processes and catalyst systems are constantly being
evaluated; however, the identities of improved and/or additional
effective catalyst systems for these processes continue to elude
the industry. Consequently, a long felt, yet unsatisfied need
exists for new and improved methods and catalyst systems for
producing aromatic carbonates and the like.
SUMMARY OF THE INVENTION
[0010] Accordingly, the present invention is directed to a method
and catalyst system for producing aromatic carbonates. In one
embodiment, the method includes the step of contacting at least one
aromatic hydroxy compound with oxygen and carbon monoxide in the
presence of a carbonylation catalyst system having catalytic
amounts of the following components: a Group VIII B metal source; a
combination of inorganic co-catalysts including a copper source and
at least one of a titanium source or a zirconium source; an onium
chloride composition; and a base.
[0011] In various alternative embodiments, the carbonylation
catalyst system can include catalytic amounts inorganic co-catalyst
combinations of a lead source and at least one of a titanium source
or a manganese source.
BRIEF DESCRIPTION OF THE DRAWING
[0012] Various features, aspects, and advantages of the present
invention will become more apparent with reference to the following
description, appended claims, and accompanying drawing, wherein the
FIGURE is a schematic view of a device capable of performing an
aspect of an embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] The present invention is directed to a method and catalyst
system for producing aromatic carbonates. In one embodiment, the
method includes the step of contacting at least one aromatic
hydroxy compound with oxygen and carbon monoxide in the presence of
a carbonylation catalyst system having catalytic amounts of the
following components: a Group VIII B metal source; a combination of
inorganic co-catalysts; an onium chloride composition; and a
base.
[0014] For convenience, the constituents of the catalyst system
described herein are called "components" irrespective of whether a
reaction between specific components actually occurs either before
or during the carbonylation reaction. Therefore, the catalyst
system may include the components and any reaction products
thereof.
[0015] Unless otherwise noted, the term "catalytic amount," as used
herein, includes that amount of a component capable of either
increasing (directly or indirectly) the yield of the carbonylation
product or increasing selectivity toward an aromatic carbonate.
Optimum amounts of a given component can vary based on reaction
conditions and the identity of other components, yet can be readily
determined in light of the discrete circumstances of a given
application.
[0016] Aromatic hydroxy compounds which may be used in the present
process include aromatic mono or polyhydroxy compounds, such as
phenol, cresol, xylenol, resorcinol, hydroquinone, and bisphenol A.
Aromatic organic mono hydroxy compounds are preferred, with phenol
being more preferred.
[0017] In various preferred embodiments, the carbonylation catalyst
system contains at least one constituent from the Group VIII B
metals or a compound thereof. A preferred Group VIII B constituent
is a catalytic amount of a palladium source. The palladium source
may be a non-supported Pd(II) salt or complex. As used herein, the
term "non-supported" indicates the absence of industrially
conventional catalyst supports based on carbon, element oxides,
element carbides or element salts in various presentations.
Examples of supports containing carbon are coke, graphite, carbon
black and activated carbon. Examples of element oxide catalyst
supports are SiO.sub.2 (natural or synthetic silicas, quartz),
Al.sub.2O.sub.3 (.alpha.-, .gamma.- Al.sub.2O.sub.3), aluminas,
natural and synthetic aluminosilicates (zeolites), TiO.sub.2
(rutile, anatase), ZrO.sub.2 and ZnO. Examples of element carbides
and salts are SiC, AlPO.sub.4, BaSO.sub.4, and CaCO.sub.3.
[0018] Accordingly, suitable palladium sources include palladium
halides, nitrates, carboxylates, oxides and palladium complexes
containing carbon monoxide, amines, phosphines or olefins. As used
herein, the term "complex" includes coordination or complex
compounds containing a central ion or atom. The complexes may be
nonionic, cationic, or anionic, depending on the charges carried by
the central atom and the coordinated groups. Other common names for
these complexes include complex ions (if electrically charged),
Werner complexes, and coordination complexes.
[0019] In various applications, it may be preferable to utilize
palladium(II) salts of organic acids, including carboxylates with
C.sub.2-6 aliphatic acids. Palladium(II) acetylacetonate and
dichloro(1,4-bis(diphenylphosphino)butane) palladium (II) are also
suitable palladium sources. Preferably, the amount of Group VIII B
metal source employed should be sufficient to provide about 1 mole
of metal per 800-10,000 moles of aromatic hydroxy compound. More
preferably, the proportion of Group VIII B metal source employed
should be sufficient to provide about 1 mole of metal per
2,000-5,000 moles of aromatic hydroxy compound.
[0020] The carbonylation catalyst system further contains a
catalytic amount of an onium chloride composition, such as an
organic onium chloride salt. The salt may be a quaternary ammonium
or phosphonium chloride salt, or a hexaalkylguanidinium chloride
salt. In various embodiments, .alpha.,
.omega.-bis(pentaalkylguanidinium)alkane chloride salts may be
preferred. Suitable onium chloride compositions include
tetrabutylammonium chloride, tetraethylammonium chloride, and
hexaethylguanidinium chloride. In preferred embodiments, the
carbonylation catalyst system can contain between about 5 and about
2000 moles of chloride per mole of palladium employed, and, more
preferably, between about 50 and about 1000 molar equivalents of
chloride are used.
[0021] The carbonylation catalyst system also includes a catalytic
amount of a base. Any desired bases or mixtures thereof, whether
organic or inorganic may be used. A non-exclusive listing of
suitable inorganic bases include alkali metal hydroxides and
carbonates; C.sub.2-C.sub.12 carboxylates or other salts of weak
acids; and various alkali metal salts of aromatic hydroxy
compounds, such as alkali metal phenolates. Hydrates of alkali
metal phenolates may also be used. Examples of suitable organic
bases include tertiary amines and the like. Preferably, the base
used is an alkali metal salt incorporating an aromatic hydroxy
compound, more preferably an alkali metal salt incorporating the
aromatic hydroxy compound to be carbonylated to produce the
aromatic carbonate. A preferred base is sodium phenoxide. In
preferred embodiments, between about 5 and about 1000 molar
equivalents of base are employed (relative to palladium), and, more
preferably, between about 100 and about 700 molar equivalents of
base are used.
[0022] The carbonylation catalyst system includes a catalytic
amount of a combination of inorganic co-catalysts (IOCC's). It has
been discovered that certain IOCC combinations can effectively
catalyze the carbonylation reaction in the presence of the
aforementioned catalyst system components. Such IOCC combinations
include lead and titanium; lead and manganese; copper and titanium;
and copper and zirconium. Additional IOCC's may be used in the
carbonylation catalyst system, provided the additional IOCC does
not deactivate (i.e. "poison") the original IOCC combination.
Examples of additional IOCC's include zinc and cerium.
[0023] An IOCC can be introduced to the carbonylation reaction in
various forms, including salts and complexes, such as tetradentate,
pentadentate, hexadentate, or octadentate complexes. Illustrative
forms may include oxides, halides, carboxylates, diketones
(including beta-diketones), nitrates, complexes containing carbon
monoxide or olefins, and the like. Suitable beta-diketones include
those known in the art as ligands for the IOCC metals of the
present system. Examples include, but are not limited to,
acetylacetone, benzoylacetone, dibenzoylmethane,
diisobutyrylmethane, 2,2-dimethylheptane-3,5-dione,
2,2,6-trimethylheptane-3,5-dione, dipivaloylmethane, and
tetramethylheptanedione. The quantity of ligand is preferably not
such that it interferes with the carbonylation reaction itself,
with the isolation or purification of the product mixture, or with
the recovery and reuse of catalyst components (such as palladium).
An IOCC may be used in its elemental form if sufficient reactive
surface area can be provided. However, it is preferable that an
IOCC is non-supported as discussed above relative to the Group VII
B metals.
[0024] IOCC's are included in the carbonylation catalyst system in
catalytic amounts. In this context a "catalytic amount" is an
amount of IOCC (or combination of IOCC's) that increases the number
of moles of aromatic carbonate produced per mole of Group VIII B
metal utilized; increases the number of moles of aromatic carbonate
produced per mole of chloride utilized; or increases selectivity
toward aromatic carbonate production beyond that obtained in the
absence of the IOCC (or combination of IOCC's). Optimum amounts of
an IOCC in a given application will depend on various factors, such
as the identity of reactants and reaction conditions. For example,
when palladium is included in the reaction, the molar ratio of
copper relative to palladium at the initiation of the reaction is
preferably between about 0.1 and about 100.
[0025] The carbonylation reaction can be carried out in a batch
reactor or a continuous reactor system. Due in part to the low
solubility of carbon monoxide in organic hydroxy compounds, such as
phenol, it is preferable that the reactor vessel be pressurized. In
preferred embodiments, gas can be supplied to the reactor vessel in
proportions of between about 2 and about 50 mole percent oxygen,
with the balance being carbon monoxide and, in any event, outside
the explosion range for safety reasons. It is contemplated that
oxygen can be supplied in diatomic form or from another oxygen
containing source, such as peroxides and the like. Additional gases
may be present in amounts that do not deleteriously affect the
carbonylation reaction. The gases may be introduced separately or
as a mixture. A total pressure in the range of between about 10 and
about 250 atmospheres is preferred. Drying agents, typically
molecular sieves, may be present in the reaction vessel. Reaction
temperatures in the range of between about 60.degree. C. and about
150.degree. C. are preferred. Gas sparging or mixing can be used to
aid the reaction.
[0026] In order that those skilled in the art will be better able
to practice the present invention reference is made to the FIGURE,
which shows an example of a continuous reactor system for producing
aromatic carbonates. The symbol "V" indicates a valve and the
symbol "P" indicates a pressure gauge.
[0027] The system includes a carbon monoxide gas inlet 10, an
oxygen inlet 11, a manifold vent 12, and an inlet 13 for a gas,
such as carbon dioxide. A reaction mixture can be fed into a low
pressure reservoir 20, or a high pressure reservoir 21, which can
be operated at a higher pressure than the reactor for the duration
of the reaction. The system further includes a reservoir outlet 22
and a reservoir inlet 23. The gas feed pressure can be adjusted to
a value greater than the desired reactor pressure with a pressure
regulator 30. The gas can be purified in a scrubber 31 and then fed
into a mass flow controller 32 to regulate flow rates. The reactor
feed gas can be heated in a heat exchanger 33 having appropriate
conduit prior to being introduced to a reaction vessel 40. The
reaction vessel pressure can be controlled by a back pressure
regulator 41. After passing through a condenser 25, the reactor gas
effluent may be either sampled for further analysis at valve 42 or
vented to the atmosphere at valve 50. The reactor liquid can be
sampled at valve 43. An additional valve 44 can provide further
system control, but is typically closed during the gas flow
reaction.
[0028] In the practice of one embodiment of the invention, the
carbonylation catalyst system and aromatic hydroxy compound are
charged to the reactor system. The system is sealed. Carbon
monoxide and oxygen are introduced into an appropriate reservoir
until a preferred pressure (as previously defined) is achieved.
Circulation of condenser water is initiated, and the temperature of
the heat exchanger 33 (e.g., oil bath) can be raised to a desired
operating temperature. A conduit 46 between heat exchanger 33 and
reaction vessel 40 can be heated to maintain the desired operating
temperature. The pressure in reaction vessel 40 can be controlled
by the combination of reducing pressure regulator 30 and back
pressure regulator 41. Upon reaching the desired reactor
temperature, aliquots can be taken to monitor the reaction.
EXAMPLES
[0029] The following examples are included to provide additional
guidance to those skilled in the art in practicing the claimed
invention. While some of the examples are illustrative of various
embodiments of the claimed invention, others are comparative and
are identified as such. The examples provided are merely
representative of the work that contributes to the teaching of the
present application. Accordingly, these examples are not intended
to limit the invention, as defined in the appended claims, in any
manner. Unless otherwise specified, all parts are by weight, and
all equivalents are relative to palladium. Reaction products were
verified by gas chromatography. All reactions were carried out in a
glass, batch reactor at 100.degree. C. in an approximately 6-7%
O.sub.2 in CO atmosphere at an operating pressure of 108.9 atm.
Reaction time was 3 hours for each run. Each reaction was run in
replicate (3.times. or 4.times.) with the average of the replicate
runs reported herein.
[0030] As discussed supra, the economics of aromatic carbonate
production is dependent on the number of moles of aromatic
carbonate produced per mole of Group VIII B metal utilized. In the
following examples, the aromatic carbonate produced is
diphenylcarbonate (DPC) and the Group VIII B metal utilized is
palladium. For convenience, the number of moles of DPC produced per
mole of palladium utilized is referred to as the palladium turnover
number (Pd TON). Various preferred embodiments of the present
method produce Pd TON of at least 1500. Even more preferred
embodiments produce Pd TON of at least 2500.
Example 1
[0031] Diphenyl carbonate was produced by adding, at ambient
conditions, 0.25 mM dichloro(1,4-bis(diphenylphosphino)butane)
palladium(II) ["Pd(dppb)Cl.sub.2"], 600 equivalents of chloride in
the form of tetrabutylammonium chloride ("TBAC"), 150 equivalents
of phenoxide in the form of sodium phenoxide ("NaOPh"), and an IOCC
combination of lead and titanium in various amounts to a glass
reaction vessel containing phenol. Lead was supplied as lead (II)
oxide ("PbO") and titanium as titanium(IV) oxide acetylacetonate
("TiO(acac).sub.2"). The components were heated to 100.degree. C.
for 3 hours in an approximately 6-7% oxygen in carbon monoxide
atmosphere. The following results were observed:
1 Experiment Pd(dppb)Cl.sub.2 PbO TiO(acac).sub.2 No. mM
Equivalents Equivalents Pd TON 1 .25 24 5.6 1847 2 .25 50 5.6
2124
[0032] The various reaction conditions show that a Pd TON at least
as high as 2124 can be obtained utilizing this catalyst system.
Based on the results of these experiments, it is evident that a
catalyst system containing Pd, a base, an onium chloride, Pb, and
Ti can effectively catalyze the carbonylation reaction.
Example 2
[0033] The general procedure of Example 1 was repeated with 0.25 mM
Pd(dppb)Cl.sub.2, 600 equivalents of TBAC, 150 equivalents of
NaOPh, and an IOCC combination of 50 equivalents of lead and 5.6
equivalents of manganese. Lead was supplied as PbO and manganese as
manganese (III) acetylacetonate ("Mn(acac).sub.3"). The average Pd
TON was found to be 2375, thus showing that the combination of Pd,
base, onium chloride, Pb, and Mn can effectively catalyze the
carbonylation reaction.
Example 3
[0034] The general procedure of Examples 1 and 2 was repeated with
0.25 mM Pd(dppb)CL.sub.2, 600 equivalents of TBAC, 150 equivalents
of NaOPh, and an IOCC combination of 12 equivalents of copper and
5.6 equivalents of titanium. Copper was supplied as copper (II)
acetylacetonate ("Cu(acac).sub.2") and titanium as TiO(acac).sub.2.
The average Pd TON was found to be 4079, thus showing that the
combination of Pd, base, onium chloride, Cu, and Ti can effectively
catalyze the carbonylation reaction.
Example 4
[0035] The general procedure of Examples 1-3 was repeated with 0.25
mM Pd(dppb)Cl.sub.2, 600 equivalents of TBAC, 150 equivalents of
NaOPh, and an IOCC combination of 50 equivalents of copper and 12
equivalents of zirconium. copper was supplied as Cu(acac).sub.2 and
zirconium as zirconium (IV) butoxide ("Zr(OBu).sub.4"). The average
Pd TON was found to be 2350, thus showing that the combination of
Pd, base, onium chloride, Cu, and Zr can effectively catalyze the
carbonylation reaction.
Comparative Example A
[0036] To show the comparative effectiveness of the previously
detailed catalyst systems, replicate runs were conducted using the
general procedure of Examples 1-4 with the following catalyst
system components: 0.25 mM Pd(dppb)Cl.sub.2, 600 equivalents of
TBAC, and 50 equivalents of PbO. The results are shown below:
2 Experiment Pd(dppb)Cl.sub.2 PbO NaOPh No. mM Equivalents
Equivalents Pd TON 1 .25 50 0 497 2 .25 50 150 1623
[0037] These results illustrate that the catalyst systems of
Examples 1 and 2 perform substantially better than the present
system with or without added base at the conditions utilized.
Comparative Example B
[0038] Replicate runs were conducted using the general procedure of
Examples 1-4 with the following catalyst system components: 0.25 mM
Pd(dppb)Cl.sub.2, 600 equivalents of TBAC, and 24 equivalents of
Cu(acac).sub.2. The results are shown below:
3 Experiment Pd(dppb)Cl.sub.2 Cu(acac).sub.2 NaOPh No. mM
Equivalents Equivalents Pd TON 1 .25 24 0 42 2 .25 24 150 957
[0039] These results illustrate that the catalyst systems of
Examples 3 and 4 perform substantially better than the present
system with or without added base at the conditions utilized.
[0040] It will be understood that each of the elements described
above, or two or more together, may also find utility in
applications differing from the types described herein. While the
invention has been illustrated and described as embodied in a
method and catalyst system for producing aromatic carbonates, it is
not intended to be limited to the details shown, since various
modifications and substitutions can be made without departing in
any way from the spirit of the present invention. For example,
additional effective IOCC compounds can be added to the reaction.
As such, further modifications and equivalents of the invention
herein disclosed may occur to persons skilled in the art using no
more than routine experimentation, and all such modifications and
equivalents are believed to be within the spirit and scope of the
invention as defined by the following claims.
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