Note: Descriptions are shown in the official language in which they were submitted.
~ 6~7 RD-936~ -
This invention relates to an improved catalytic
aromatic carbonate process which comprises contacting
under substantially anhydrous reaction conditions
a phenol, carbon monoxide, an oxidant other than and in
addition to oxygen, a base, a Group VIIIB element
selected from ruthenium, rhodium, palladium, osmium,
iridium or platinum. A preferred embodiment comprises
the use of a molecular sieve drying agent in the
process.
In the copending Canadian patent application
of A.J. Chalk, Serial No. 300,634 filed April 6, 1978
and commonly assigned herewith, it is broadly disclosed
that aromatic carbonates can be prepared by contacting a
phenol, carbon monoxide, an oxidant, a base and a Group VIIIB
element selected from ruthenium, rhodium, palladium, osmium,
iridium or platinum.
Unexpectedly, I have found that optimum aromatic
carbonate process yields result when a phenol, carbon
monoxide, an oxidant other than and in addition to
oxygen, a base and a Group VIIIB element are contacted
in the presence of a drying agent, especially when
molecular sieves are used to promote substantially
anhydrous reaction conditons. Further, unexpectedly I
have found that even more optimum aromatic carbonate
process yields result when my process is carried out
in the presence of a manganese or cobalt complex redox
cocatalyst compound.
This invention embodies an improved catalytic aromatic
~ ~ .
RD-9368
637
carbonate process which comprises contacting in the presence
of a drying agent a phenol, carbon monoxide, an oxidant
other than and in addition to oxygen, a base, and a Group
VIIIB element selected from ruthenium, rhodium, palladium,
osmium, iridium or platinum. -
The reactants and the resulting reaction products of
my process can be illustrated by the following general
equations which are furnished for illustrative purposes
only since the reaction mechanisms involved in the pre-
paration of aromatic monocarbonates (Eq. 1) and poly-
carbonates (Eq. 2) may be much more complex:
Eq. 1 2R'OH + CO + 1/22 ~ R'2C3 + H20
Eq. 2 n+l R''(OH)2 + nCO + 1/2nO2
HO ~''-~C~ OH + nH2O
n
wherein R is an alkyl radical (including cycloalkyl), R' is
an aryl radical, R'' is an arene radical, and n is a number
at least equal to 1.
Any nuclearly hydroxy substituted aromatic compound
can be used in my process and is defined herein and in the
appended claims as "a phenol". Illustratively the phenol
(or phenolic reactants) can be described by the formula:
I. a ( OH)
wherein Ra represents an aromatic radical, where the -OH
radical is attached directly to an aromatic ring carbon
atom and x is a number being at least equal to 1, advantage-
ously from 1 to 4, and preferably from 1 to 2. The Ra
radical can be carbo- or hetero-monocyclic, polycyclic, or
637 RD--9368
fused polycyclic, and can have two or more cyclic systems
(monocyclic, polycyclic or fused polycyclic systems) which
are connected to each other or by bi- or multivalent
radicals.
Preferred phenolic reactants are phenols containing
from 6 to 30, and more preferably from 6 to 15 carbon atoms.
Illustrative of commercially important phenolic reactants
included within the above description are the following:
phenol itself (hydroxy benzene), napthol, ortho-, meta-, or
paracresol, catechol, cumenol, xylenol, resorcinol, the
various isomers of dihydroxydiphenyl, the isomers of dihy-
droxynapthalene, bis(4-hydroxyphenyl)propane-2,2,Cx, ~'
-bis(4-hydroxyphenyl)-p-diisopropylbenzene, 4,4'-dihydroxy-
3,5,3',5'-tetrachlorophenyl-propane-2,2,4,4'-dihydroxy-3,5,
3',5'-tetrachloro-phenyl-propane-2,2 and 4,4'-dihydroxy-3,
5,3',5'-tetrachloro-phenylpropane-2,2 and 4,4'dihydroxy-3,5,3'
5'-tetrabromo-phenylpropane-2,2,phloroglucinol, dihydroxy
oligomers, for example an oligomer derived from bisphenol-
A, etc.
A generally preferred bisphenol that can be used in
my process can be described by the following formula:
II. 3
R \ R3
~--\ Rl ~--~
HO ~ R2 ~ OH ,
R4 R4
~8637
~D-9368
where Rl and R2 are hydrogen, C~ 4 alkyl or phenyl, ~t least
one of R is hydrogen and the other is hydrogen or Cl 4 al~yl,
and at least one of R4 is hydrogen and the other is hydrogen
or Cl 4 alkyl, E8pecially preferred is bis(4-hydroxyphenyl)
propane-2,2, also commonly known as "bisphenol-A" (BPA),
Any Group VIIIB elemen~, defined herein and in the
.
appended claims as "~eGroup VIIIB element", can be employed -
subject to the proviso that it is selected from ruthenium,
rhodium, palladium, osmium, iridium or platinum. The Group
VIIIB elements can be employed in any of their well-known
oxidation states as well as their zero valent elemental, `i.e.
metallic, formO
Illustratively, the Group VIIIB elements can be
present in ionic, inorganic or organic compound or complex,
etc. formsO The Group VIIIB elements can be employed in oxide,
halide, nitrate, sulfate, oxalate, acetate, carbonate,
propionate, hydroxide, tartrate, etc., forms.
The Group VIIIB elementscanbeemployedin complex fonm, e.g. with
ligands, such as carbon monoxide, nitriles, tertiary amines, ;;
`phosphines, arsines, or stibines, etc., and
s illustratively are often represented by those skilled in the
,.~
~ art as mono-, di-, or poly- nuclear Group VIIIB element forms.
i Generally, the dimeric or polymeric forms are considered to
contain Group VIIIB atoms bridged by ligands, halogens, etc. Pref-
erably the Group VIIIB elements form homogeneous mixtures when
1 ~
-- 4
! RD-9368
37
combined with the phenolic reactants, especially when the
process is carried out under liquid phase reaction conditions.
Illustrative of the generally preferred Group VIIIB
element compounds or complexes that can be used in my process
follow: Ru, RuC12, RuBr2, RuI2, Ru(C0)2C12, Ru(C0)2I2, Ru(C0)4-
C12, Ru(CO)4Br2, Ru(C0)4I2, RuC13, RuBr3, RuI3, etc.,
Pd, PdC12, PdBr2, PdI2, [Pd(CO)C12]2,
[ ( ) 2]2~ [Pd(CO)I2]2, (C6H5CN)2PdC12~ PdC14~ Pd(OH)2-
4 9 2 2 6 5)2 Pd(OH)2(CNCH30C6H5)2, Pd(CNC H ) et
Rh, Rh(CO)C12, Rh(CO)Br2, Rh(CO)I2, Rh2C12(C0)2, Rh2(C0)4C12,
Rh2(CO)4Br2, Rh2(C0)4I2, [Rh(C0)2C1]2, RhC13, RhBr3, RhI3, etc.,
OS, OS(CO)3C12, OS(CO)3Br2~ Os(CO)3I2~ Os(CO)4C12, OS(CO)4Br2~
Os(C0)4I2, Os(C0)8C12, Os(CO)8Br2, Os(C0)8I2, OsC12, OsC13, OsI2,
OsI3, OsBr3, OsBr4 and OsC14, etc., Ir, IrC13, IrC13(CO), Ir2(Co)8,
IrC13, IrBr3, IrC13, IrBr4, IrI4, etc., Pt, PtC12, PtBr2, PtI2,
Pt(C0)2C12, Pt(CO)2Br2, Pt(C0)2I2, Pt(C0)2C14, Pt(CO)2Br4,
Pt(C0)2I4, Pt(C0)3C14, Pt(CO)3Br4, Pt(C0)3I4, PtC12(CNC6H5)2, etc-
Illustrative of ligands that can be associated with
the Group VIIIB elements in complex form -- other than and,
optionally, in addition to carbon monoxide -- include organic
tertiary amines, phosphines, arsines and stibine ligands of the
following formula:
(E)3Q
wherein, independently, each E is selected from the radicals r
Z and OZ, where independently each Z is selected from organic
....
`'~'.
-- RD-9368
637
radicals containing from 1 to 20 carbon atoms, and wherein
independently each Q is selected from nitrogen, phosphorus,
arsenic or antimony. Preferably, the organic radicals are free
of active hydrogen atom~, reactive unsaturation, and are
oxidatively stable. More preferably, the E groups are alkyl,
cycloalkyl and aryl radicals and mixtures thereof, such as
alkaryl, aralkyl, alkcycloalkyl containing from 1 to 10 carbon
atoms, and even more preferably each E is an aryl group contain-
ing from 6 to lO carbon atoms.
Illustrative of the generally known presently preferred
Group VIIIB complexes which contain ligands include the
2[ ( 6H5)3]4~ [Rh(CO)2C1]2, tranS[(c2H~5P]2pdBr
4 9 3 2 4, [ 6 5)3P]3IrCl3(cO)~ [(c6H5)3As]3Ircl (CO)
[(c6H5)3sb]3Ircl3(co)~ [(C6Hs)3P]2ptcl2~ [(C6H5)3P]2pt 2'
[(c6H5)3P]2ptF2(co)2~ Pt[(C6H5~3P]2~ )2
The Group VIIIB element compounds and/or complexes
can be prepared by any method well-known to those skilled in the
art including the methods referenced in the following publica-
tions:
Treatise on Inor~anlc Chemistry, Volume II, H. Remy,
Elsevier Publishing Co. (1956);
Reactlons of Transition-Metal Complexes, J.P.
Candlin, K.A. Taylor and D.T. Thompson,
Elsevier Publishing Co. (1968) Library of
Congress Catalog Card No. 67-19855;
'','1
~ - 6 -
1~8637 RD-9368
Or~anic Svntheses Via Metal ~arbonyls, ~Tol. 1,
I. Wender and P. Pino, Interscience
Publishers (1968) Library of Congress
Catalog Card No. ~7-13965;
The Or~anic Chemistrv of Palladium, Vols. I ~nd II,
P.M. Maitlis, Academic Press (1971) Library o.
Congress Catalog ~ard No. 77-1~2937;
The Chemistry of ''la~lnum and Palladium, F,R,
Hartley, Hals,ed ~ress (1973);
The process can be carried out in the absence of
; any solvent, e.g. where the phenolic reactant acts as both a
reactant and a solvent, however preferably is carried out in the
presence of a solvent, and more preferably solvents of the
general class: methylene chloride, ethylene dichloride,
chloroform, carbon tetrachloride, tetrachloroethylene, nitro-
methane, hexane, 3-methylpentane, heptane, cyclohexane,
methylcyclohexane, cyclohexane, isooctane, p-cymene, cumene,
decalin, toluene, benzene, diphenylether, dioxane, thiophene,
dimethyl sulfide, ethyl acetate, tetrahydrofuran, chlorobenzene,
anisol, bromobenzene, o-dichlorobenzene, methyl formate,
iodobenzene , acetone, acetophenone, etc., and mixtures thereof.
In general, the process can be carried out in any
basic reaction medium, preferably, that provided by the presence
of any inorganic or organic base or mixtures thereof.
Representative of basic species which can be employed are the
37 RD - 9 3 6 8
following: elemental alkali and alkaline earth metals;
basic quaternary ammonium, quaternary phosphonium or
tertiary sulfonium compounds; alkali or alkaline earth
metal hydroxides; salts of strong bases and weak acids;
primary, secondary or tertiary amines; etc. Specific
examples of the aforementioned are sodium, potassium,
magnesium metals, etc.; quaternary ammonium hydroxide,
tetraethyl phosphonium hydroxide, etc.; sodium, potassium,
lithium, and calcium hydroxide; quaternary phosphonium, tertiary
sulfonium, sodium, lithium and barium carbonate, sodium
acetate, sodium benzoate, sodium methylate, sodium
thiosulfate, sodium sulfide, sodium tetrasulfide, sodium
cyanide, sodium hydride, sodium borohydride, potassium
fluoride, triethylamine, trimethylamine, allyldiethylamine,
benzyldimethylamine, dioctylbenylamine, dimethylphenethylamine,
l-dimethylamino-2-phenylpropane, N,N,N', N'-tetramethylenediamine,
2,2,6,6-tetramethylpyridine, N-methyl piperidine, pyridine,
2,2,6,6-N-pentamethylpiperidine, etc. Especially
preferred bases are sterically hindered amines, e.g.
diisopropylmonoethylamine, 2,2,6,6,N-pentamethylpiperidine,
etc.
Any oxidant can be employed in the herein
claimed process subject to the proviso that the oxidant
is an element selected from the class consisting of
Groups IIIA, IVA, VA, VIA, IB, IIB, VIB, VIIB and
VIIB, or a compound or complex thereof, and the oxidant
has an oxidation potential greater than or more positive
; than the Group VIIIB element. Typical oxidants
for the Group VIIIB elements are compounds of copper,
: 30 iron, manganese, cobalt, mercury, lead, cerium, uranium,
- .
~ RD-9368
8~37
bismuth, chromium, etc. Of these, copper salts are preferred.
The anion of the salt may be a Cl 20 carboxylate, halide, nitrate,
sulfate, etc., and preferably is a halide, e.g., chloride,
bromide, iodide, or fluoride. Illustrative of typical oxidant
compounds are cupric chloride, cupric bromide, cupric nitrate,
cupric sulfate, cupric acetate, etc. In addition to the com-
pounds described above, gaseous oxygen may be employed as the
sole oxidant in the herein claimed process. Typically, compounds
or complexes of a periodic Group IIIA, IVA, VA, IB, IIB, VB, VIB,
VIIB, and VIIIB element are preferably employed, in conjunction
with oxygen, as redox co-catalysts in order to enhance the rate
of oxidation of the Group VIIIB metal by gaseous oxygen.
As used herein and in the appended claims, the expres-
sion "complexes" includes coordination or complex compounds well-
known to those skilled in the art such as those described in
Mechanisms of Inorganic Reactions, Fred Basolo and Ralph G.
.
Pearson, 2nd Edition, John Wiley and Sons, Inc. (1968). These
compounds are generally defined herein as containing a central
ion or atom, i.e. a periodic Group IIA, IVA, VA, VIA, IB, IIB,
VIB~ VIIB or VIIIB element and a cluster of atoms or molecules
surrounding the periodic group element. The complexes may be
nonionic, or a cation or anion, depending on the charges carried
; by the central atom and the coordinated groups. The coordinated
groups are defined herein as ligands, and the total number of
attachments to the central atom is defined herein as the
coordination number. Other common names for these complexes in-
clude complex ions (if electrically charged), Werner complexes,
.
RD-9368
637
coordination complexes or, simply, complexes.
The redox components as a class comprise any compound
or complex of a periodic Group IIIA, IVA, VA, IB, IIB, VB, VIB,
VIIB and VIIIB, which catalyze the oxidation of the Group VIIIB
elements, i.e. ruthenium, rhodium, palladium, osmium, iridium or
platinum in the presence of oxygen, from a lower oxidation state
to a higher oxidation state.
Any source of oxygen can be employed, i.e., air, -
gaseous oxygen, liquid oxygen, etc. Preferably either air or
gaseous oxygen are employed.
Any amount of oxygen can be employed. Preferably the
process is carried out under positive oxygen pressure, i.e.,
- where oxygen is present in stoichiometric amounts sufficient to
form the desired aromatic mono- or polycarbonate. In general,
oxygen pressures within the range of from about 0.1 to 500
atmospheres, or even higher, san be employed with good results.
Presently preferred are oxygen pressures within the range of
from about 1/2 to 200 atmospheres. r
~v'
'';~
.'''
' ~
-- 10 --
. :: ", ' '
. ~
''' :. '
RD-9368
3637
Any amount of the oxidant can be employed. For example,
oxidant to phenol mole proportions within the range of from about
0.001:1 or lower to about 1000:1 or higher are effective; however,
preferably ratios from 0.1:1 to 10:1 are employed to insure an
optimum conversion of phenol to aromatic carbonate. It is essen-
tial wherein an oxidant is employed--in the substantial absence of
oxygen, i.e. not as a redox co-catalyst component --
that the oxidant be present in amounts stoichiometric to carbonate
o
moieties; i.e., -0-C-0-, formed in the preparation of the aromatic
carbonates.
Any amount of redox co-catalyst component can be employed
For example, redox catalyst to phenol mole proportions within the
range of from about 0.0001:1 or lower to about 1000:1 or higher
are effective; however, preferably ratios of from .0001:1 to
1:1, and more preferably 0.001:1 to 0.01:1 are employed.
Any amount of base can be employed. In general,
effective mole ratios of base to the Group VIIIB elements are
within the range of from about 0.00001:1 to about 100:1 or higher,
preferably from 0.5:1 to about 10:1, and more preferably from
1:1 to 2:1. Generally, mole ratios of at least 1:1 enhance
both the reaction rate and the yield of aromatic carbonate.
Any amount of the Group VIIIB element can be employed.
For example, Group VIIIB element to phenol mole proportions
within the range of from about 0.0001:1 or lower to about
1000:1 or higher are effective; however, preferably ratios of
~f
I f ~,
. ..
`' :
- RD-9368
i3~
from 0.001 to 0.01 are employed in my catalytic reaction.
Any amount of carbon monoxide can be employed. Prefer-
ably the process is carried out under positive carbon monoxide
pressure; i.e., where carbon monoxide is present in stoichio-
metric amounts sufficient to form the desired aromatic mono- or
polycarbonate. In general, carbon monoxide pressures within the
range of from about 1/2 to 500 atmospheres, or even higher, can
be employed with good results. Presently preferred are CO
pressures within the range of from 1 to 200 atmospheres.
Any amount of solvent, preferably inert, can be em-
ployed. In general, optimum solvent to phenolic reactant mole
proportions are from 0.5:99.5 to 99.5:0.5, preferably from
50:50 to 99:1.
Any reaction temperature can be employed. In general,
optimum reaction temperatures are 0C, or even lower, to 200C,
or even higher and more often 0C to 50C. r
Any reaction time period can be employed. Generally
optimum reaction time periods are about 0.1 hour or even less
to about 10 hours or even more.
Following some of the procedures described herein,
aromatic salicylates can be formed. These aromatic salicylates,
i.e. aromatic compounds which can be defined as "salicylate",
can be generically described by the following formula:
O
HO Rb C-0-Rc
wherein Rb represents an aromatic radical wherein the hydroxyl
- 12 -
~ ,,
.
~ 6 37 RD-9368
radical is positioned ortho relative to the carboxylate, i.e.
o
-C-O- radical, and Rc represents an aromatic radical. The
Rb and Rc radicals can be carbo- or hetero-monocyclic, poly-
cyclic, or fused polycyclic, and can have two or more cyclic
systems (monocyclic, polycyclic or fused polycyclic systems)
which are directly joined to each other by single or double
valence bonds, or by bi- or multivalent radicals.
The reaction parameters essential to the practice of
my process comprise those detailed in the previously
mentioned Chalk application. However, it is essential
that my invention be carried out under conditions which
remove from the reaction zone the water generated in
reaction equations 1 and 2. My process is preferably
carried out under reaction conditions wherein no measurable
amount of water can be detected during the course of the
reaction. Substantially anhydrous reaction conditions are
defined herein and in the appended claims as the practice
of my process carried out in the presence of any drying
agent which will take up a measurable amount of any water
formed as described hereinbefore by Equations 1 and 2.
The drying agents are preferably inert and can be any of
; those known to those of ordinary skill in the art. They
can be classified by any means, e.g. regenerative or non-
regenerative; liquid or solid; chemical reaction, i.e.
the formation of a new compound or a hydrate; physical
absorption at constant or variable relative humidity;
adsorption, etc. Preferably, the drying agent(s) employed
in my process have high capacity and/or efficiency and
preferably both in removing moisture from the reaction medium.
As employed herein, the term "capacity" refers to the amount
of water that can be removed from a given weight of the
reaction medium and the efficiency refers to the degree of
- 13 -
~D-9368
8637
dryness that can be produced by the drying agent. Among
the many drying agents that can be employed are activated
alumina, barium oxide, calcium chloride, calcium oxide,
calcium sulfate, lithium chloride, molecular sieves, e.g.
drying agents made from natural or synthetic crystalline
alkali metal aluminosilicates of the zeolite type, etc.
Preferred drying agents used in the practice of my invention
are natural and synthetic zeolities well known to the art
such as those described in detail in the publication
Molecular Sieves, Charles K. Hersh, Reinhold Publishing
Company, New York (1961). Representative natural zeolities
which may be used include those in Table 3-1, page 21 of
the Hersh reference. Additional useful zeolite drying agents
are set forth in Organic Catalysis Over Crystalline Alumi-
nosilicates, P.B. Venuto and P.S. Landis, Advances in Catalysis,
. .
Vol. 18, pp. 259-371 (1968). Particularly useful molecular
sieves are those designated by the Linde Division of the
Union Carbide Corporation as zeolite types A, X and Y,
.l;i7 ~
described in U.S. Patents 2,882,243 dated April 14,1959, ;~
3,130,007 dated April 21, 1964 and U.S. 3,529,033 dated
, 20 September 15, 1970. Other zeolites are, of course, included
- within the scope of this invention.
In another embodiment of my process, preferably mang-
anese or cobalt redox complexes are employed in addition
to a drying agent. Illustrative or manganese complexes
which are preferred oxidants are those commonly referred
: .
$ to as manganese chelates and includes those represented by
the general formula LMn, wherein L is a ligand derived
from an omegahydroxyoxime or an orthohydroxyareneoxime,
including mixtures thereof, and Mn is the transition metal
manganese. Illustratively, the manganese can be employed
in any of its oxidation states, e.g. from -1 to +7.
An omega-hydroxyoxime ligand, represented as "L" in the
general formula LMn,can be described by the following formula:
- 14 -
. .
1~8637 RD-9368
R
Rb--C
I. {(R ) - ~ :
~;~ N
OH
,~' ' . '''`'' ~ ':
wherein independently each ~, Rc, Rd and Re is selected from the ~-
group consisting of hydrogen, acyclic and cyclic hydrocarbon
radicals, and n is a positive integer equal to 0 or 1. ~:
il 5 An ortho-hydroxyareneoxime ligand, represented as "L"
in the general formula LMn, can be described by the following
formula~
-, ~
f
' ~ II. (NOt~~~Ar~--(C--N-OH)
wherein Rf is independently selected from tha group consisting of
~ hydrogen and acyclic hydrocarbon radicals, Ar is at least a
divalent arene radical having at least one -OH radical and at
least one
}~ If
-C = N-OH
~; radical attached directly to an ortho position arene ring carbon
atom. Methods for the preparation of manganese chelate complexes
: including mix~ures thereof are described in U.S. patents
3,956,242 dated May 11, 1976, 3,965,069 dated June/22/1976,
and U.S. Patent No. 3,972,851 dated August 3, 1976.
_ 15 _
;
~L~a!8637
RD-9368
Illustrative of genera~lly preferred manganese chelate
complexes are described by the following formulas:
H ~O
~OH ~ N~
` ~ ~N/I HO~ ~)
OH
OH ~N H
IV,
H ~OH
~,
Illustrative of cdbalt complexes which are preferred
;i oxidants are those commonly referred to as cobalt chelates and
includes those represented by the general formula:
V, I~Co ~--Ar
:1 CH - N--Rg- N = CH
wherein Ar represents a divalent arene radical and Rg represents
a-divalent organic radical containing at least 2 carbon atoms.
Methods for the preparation of cobalt chelate complexes including
mixtures thereof are described in U.S, patents 3,455,880 dated
June 15, 1969, 3,444,133 dated May 13, 1969 and u.s. Pat
3,781,382 dated December 25, 1973.
- 16 -
. ;,, ~
RD-9368
637
Generally presently preferred cobal~ chelate complexes
are described by the following ~ormulas:
VI. ~ -,Co-
CH=I N - CH
CH - CH
,~ .. ;,
~ F F
VII. ~ o_50_o~
:: CH=N N=CH
,: CH2 CH2
- '
VIII. ~ O;Co-O
CH=N NH N=CH
1/ \1
: ( 2)3 ( 2 3
~ ;
OCH3 OCH3
IX. ~ O;Co~-O
CH=N NH N=CH
1/ \t
(CH2)3 (CH2)3
X. ~o-cO~-o~ .
CH=N IN=CH
CH2 2
- 17 -
, ~ .
~1~18~37
RD-~368
Since manganese and cobalt complexes can coordinate
with water, oxygen, alcohol, amines, etc., such coordination
compounds are included within the context as oxidants in the
practice of my invention.
In my process, any amount of drying agent can be
-~ employed. Those skilled in the art can determine, ~y means of
- routine experimentation, the optimum amounts of any particular
drying agent which is selected and used in the practice of my -
invention. For example, those skilled in the art can readily
- 10 estimate the optimum amounts of molecular sieve required for
selective absorption of water by routine reference to
Linde~ Company, molecular Types 3A and 4A "Water Data Sheetsl'
, ,
, published and distributed by Union Carbide Corporation.
In order that those skilled in the art may better
understand my invention, the following examples are given which
are illustrative of the best mode of this invention, however,
these examples are not intended to limit the invention in any
manner whatsoever. In the examples, unless otherwise specified,
all parts are by weight and the reaction products were verified
by infrared spectrum, C-13 nuclear magnetic resonance and mass
spectrometry.
EXAMPLE I
A procedure,which is not an example of this invention,
for the preparation of 4,4'-(a,a-dimethylbenzyl)diphenylcarbonate
under carbon monoxide and oxygen pressure and in the absence of a
~ - 18 -
36;~7
RD-9368
drying agen~.
A reaction medium containing p-cumylphenol, bis-
(benzonitrile)palladium(II) dichloride, diisopropylmonoethyl-
amine and copper dibromide was formulated. The molP proportions
of the ingredients were as follows 100:2:15:8, respectively.
-; The reaction medium was charged with sufficient carbon monoxide
; to raise the pressure to 31 psi and sufficient oxygen to raise
the pressure from 31 psi ~o 62 psi. Subsequent workup and
analysis of the reaction idantified a product yield of 8a/o of 4,4'-
a,~(dimethylbenzyl)diphenylcarbonate of the formula:
. .
CH 0 CH
' ~o_c_~ . '~
CH3 C 3
,~ O.; 11 .
The number of carbonate moieties, i.e. -0-C-O- formed
per mole of palladium metal was 4. Hereafter this number is
referred to as the Group VIIIB "turnover value" of the reaction.
EXAMPLE II
Preparation of 4~4l(a~a-dimethylbenzyl)diphenyl-
carbonate under carbon monoxide and oxygen pressure and in the
presence of a molecular sieve Type 4A --- a commercial product of
Union Carbide Corporation of the general chemical formula
0.96 + 0.04 Na2O l.00 A1203O1.92 + 0.09 SiO2 x H2O.
The reaction medium contained p-cumylphenol, bis-
(benzonitrile)palladium(II) dichloride, diisopropylmonoethyl-
amine, and copper dibromide which were present in the following
_ 19 _
~ 7 RD-9368
mole proportions 100:2:16:8, respectively. The reaction medium
was charged with carbon monoxide to 31 ~ oxygen to o2 psi as in
Example I Subsequent analysis identified a product yield or
31% of 4,4'-a,a(dimethylbenzyl)diphenylcarbonate. As illustrated
by this example, the incluslon of a drying agent, e.g. a molecular
sieve, significantly increases the yield of aromatic carDonate, ~g.
by 400% when the yield of this example is compared with the
yield of the procedure described in Example I.
E~AMPLE III
Preparation of 4~4l-(a~a-dime~hylbenzyl)diphenyl-
carbonate using p-cumylphenol, carbcn monoxide, 2,2,o,6,N-p~r~nta-
methylpiperidine, palladium(II) dibromide, bis(ben~oinoxime)-
manganese(II) and a molecular sieve.
A reaction vessel was charged with 2.12 g. (0.010 mole)
of p-cumylphenol, 0.030 g. (0.00010 moles) of palladium(II) di-
bromide, 0.051 g. (0.00010 mole) of bis(benzoinoxime) manganese-
(II), 0.155 g. (0.0010 mole) of 2,2,6,6,N-pentamethylpiperidine,
30 ml. of methyl chloride and 2.0 g. of a Lindy Union Carbide 3A
molecular sieve which had been activated by heating at 200 C. in
vacuo. The Type 3A molecular sieve employed is a commercial
product of Union Carbide Corporation produced from Type 4A ;.
molecular sieves through ionic exchange of about 75~/O of the sodium
ions by potassium. Carbon monoxide and air were bubbled slowly
through the reaction vessel mixture at room temperature for 18
hours. Gas chromatography indicated the presence of 0.495 g.
(22.2%yield) of 4,4'-(a,a-dimethylbenzyl)diphenylcarbonate. After
- 20 -
3637
~D- q '' ~ 8
44 hours, reaction product contained 1.23 g. (55~' yield) of the
aromatic carbonate.
EXAMPLES IV-XI
Following the General Procedure of E.xample III, set out
hereinbefore, a series of reactions were run employing va-ious
oxidants for the preparation of aromatic carbonates in the
presence of molecular sieves. Summarized in Table I hereafter
are the reaction parameters and products, i e. the mole
proportions of Group VIrIB element : redox component : phenolic
reactant : base, the percent conversion of the phenolic reactant
to aromatic carbonate, the reaction time and the .urnover value.
In all of the examples, the phenolic reac~ant ~as p-
cumylphenol and the base was 2,2,~,6,N-pentamethylpi.~eridine.
The &roup VIIIB element in Examples III, V, VI and X was palladium-
(II) dibromide, and in Examples VII, VIII and I~ was palladium(I)monocarbonyl monobromide. The redox component oxidant employed
in addition to oxygen in each example is tabulated in Table I.
~ Example XI was a control run analogous to Example IV except that
- the Group VIII element was excluded from the reaction and the
:
reaction time was extended.
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~6~7 RD-9368
EXAMPLE XII
Preparation of a polycarbonate of bisphenol-A by
contacting bis(4-hydroxyphenyl)propane-2,2, carbon monoxide,
manganese (II)bis(benzoinoxime), 2,2,6,6,N-pentamethyl-
piperidine, palladium(II)dibromide, oxygen, a molecular
sieve Type 3A and air.
A flask was charged with 4.56 g. (20.0 mmol.) of
bis(4-hydroxyphenyl)propane-2,2 also known as bisphenol-A,
0.62 g. (4.4 mmol.) of 2,2,6,6,N-pentamethylpiperidine, 0.06
g. (0.20 mmol.) of palladium(II)dibromide, 0.30 g. (0.60
mmol.) to manganese(II)bis(benzoinoxime), 4 g. of molecular
sieve Type 3A and 30 ml. of methylene chloride. Carbon
monoxide and air were passed through the solution for
42 hours. Reverse phase liquid chromatography showed
the presence of bisphenol-A and bisphenol-A dimers, trimers,
pentamers and higher oligomers. An additional 0.06 g.
(0.2Q mmol.) of palladium(II)dibromide was added and the
reaction continued. The Mn number average molecular
weight of the polycarbonate was estimated at 2,800 with
about a 10~ recovery. This example demonstrates and utility
of my catalytic process in the preparation of polycarbonates
of bisphenol-A.
While not wishing to limit my invention to any
theory, it is believed that the practice of my invention
is significantly improved by the presence of molecular
sieves because of the ability of the molecular sieves to
selectively absorb carbon dioxide and water as opposed to
carbon monoxide oxygen and hydrogen.
In the practice of my process, the Group VIIIB elements,
after separation from the resulting reaction products can be
oxidized or reduced by any means to any oxidation state, and
can be re-employed, that is recycled, in the aromatic process
described herein.
23 _
~ 7 RD-9368
Although the above examples have illustrated various
modifications and changes that can be made in the carrying
out of my process, it will be apparent to those skilled in
the art that other Group VIIIB metals, phenolic compounds,
ligands, oxidants, redox components, drying agents and
solvents as well as other reaction conditions can be
effected without departing from the scope of the invention.
24 _
. ,, ~
