Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
-~RD 9366
638
~- This invention relates to a catalytic aro-
matic carbonate process comprising contacting a phenol,
carbon monoxide, an oxidant, a base, and a Group VIIIs
element selected from ruthenium, rhodium, palladium,
osmium, iridium or platinum to form a reaction mixture.
The aromatic carbonate can be isolated or separated
from the reaction mixture.
Mador et al. in United States Patent No.
3,114,762 issued December 17, 1963 described the pre-
10paration of aliphatic carbonates by the reaction of
aliphatic alcohols with carbon monoxide carried out
in the presence of a salt of palladium or platinum
metal.
Perrotti et al. in United States Patent3,846,468 issued November 5, 1974 describes the pre-
paration of carbonic acid esters by the reaction of
an alcohol with carbon monoxide and oxygen carried
. ! .
RD-9366
G;3 ~3
out in the presence of copper complexed with an organic
molecule. Although the disclosure of Perrotti et al. suggests
that elements such as iron cobalt and nickel are effective
catalysts in the reaction of al~ohols with carbon monoxide in
the presence of oxygen, it was found that when iron, cobalt or
nickel compounds are substituted for the Group VIIIB elements
employed in my process for making aromatic carbonates, such
carbonates could not be obtained under these conditions.
DESCRIPTION OF THE INVENTION
-
This invention embodies a catalytic aromatic
carbonate process which comprises contacting a phenol, carbon
monoxide, an oxidant, 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 intermediate (Eq. la, lb, and lc, or Eq. 2a, 2b and 2c)
reaction mechanisms involved in the preparation of aromatic
monocarbonates (Eq. 1) and polycarbonates (Eq. 2) may be much
more complex:
Eq. l (intermediate) (a) PdC12 + 2R'OH + 2R3N + CO
~ Pd + R 2CO3 + 2R3NH Cl
(b) Pd + 2CuCl2 > 2 CuCl + PdCl2
+
(c) 2CuCl + 2R3NH Cl ~ l/2 2 ~~~~
2CuCl2 + 2R3N + H20
~<7 .
RD-9366
~ ~6~8
: Eq. 1 ~net result) 2R'OH + CO + 1/20 ~ R'CO + H O
`:
Eq. 2 (intermediate) (a) n PdC12 + n R''(OH)2 + 2n R3N + n CO
(b) n Pd + 2n CuC12--~ 2nCuCl + nPdC12
(c) 2n CuCl + 2n R3NHCl + 1/2nO
2nCuC12 + 2nR3N + nH20
;`
Eq. 2 (net n R''(OH)2 + nCO + 1/2nO2 ~ :
result)
_
HO _ - R'' - OCO - ~ R''-OH + nH20
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)X
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, advantageously from 1 to 4,
and preferably from 1 to 2. The R radical can be carbo- or
hetero-monocyclic, polycyclic, or fused polycyclic, and can have
~ ~ RD-9366
`8
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 para~
cresol, catechol, cumenol, xylenol, resorcinol, the various
isomers of dihydroxydiphenyl, the isomers of dihydroxynapthalene,
bis(4-hydroxyphenyl)propane-2,2, ~,5~'-bis(4-hydroxyphenyl)-
p-diisopropylbenzene, 4,4'-dihydroxy-3,5,3',5'-tetrachloro-
phenyl-propane-2,2,4,4'-dihydroxy-3,5,3',5'-tetrachloro-phenyl-
propane-2,2 and 4,4'-dihydroxy-3,5,3',5'-tetrachloro-phenyl-
propane-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. R3 R3
~0 ~ C ~ 0~ ,
R R4
~'
RD-9366
638
where Rl and R2 are hydrogen, Cl 4 alkyl or phenyl, at least
one of R3 is hydrogen and the other is hydrogen or Cl 4 alkyl,
and at least one of R4 is hydrogen and the other is hydrogen
or Cl 4 alkyl. Especially preferred is bis(4-hydroxyphenyl)
propane-2,2, also commonly known as "bisphenol-A" (BPA).
Any Group VIIIB element, defined herein and in the
appended claims as "the Group 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, form.
Illustratively, the Group VIIIB elements can be
present in ionic, inorganic or organic compound or complex,
etc. forms. The Group VIIIB elements can be employed in oxide,
halide, nitrate, sulfate, oxalate, acetate, carbonate,
propionate, hydroxide, tartrate, etc., forms.
The Group VIIIB elements can be employed in complex form,
e.g. with ligands, such as carbon monoxide, nitriles, tertiary
amines, phosphines, arsines, or stibines, etc., and
illustratively are often represented by those skilled in the
art as mono-, di-, or poly- nuclear Group VIIIB element forms.
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
0~
~.:`
-
~ RD-9366
16;313 :
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)2CI2, Ru(CO)2I2, Ru(C0)4-
C12, Ru(CO)4Br2, Ru(C0)4I2, RuC13, RuBr3, RuI3, etc.,
Pd, PdC12, PdBr2, PdI2, [Pd(CO)C12]2,
pd(co)Br2]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 ) etc
Rh, Rh(CO)C12, Rh(CO)Br2, Rh(CO)I2, Rh2C12(C0)2, Rh2(C0)4C12,
Rh2(CO)4Br2~ Rh2(C0)4I2, [Rh(C0)2Cl]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,
2 4 ( )3C14, Pt(CO)3Br4, Pt(C0)3I4, PtC12(CNC H ) 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:
wherein, independently, each E is selected from the radicals
Z and OZ, where independently each Z is selected from organic
,~
~.
RD-9366
38
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 atoms, 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 10 carbon atoms.
Illustrative of the generally known presently preferred
Group VIIIB complexes which contain ligands include the
g 12[ (C6H5)3]4, [Rh(CO)2C1]2, trans[(C2H5P]2PdBr ,
4 9 3 2 4 [( 6 5)3P]3IrC13(CO),[(C6H5)3As]3IrCl (CO)
6 5 3 ]3 3(CO), [(C6H5)3P]2ptcl2~ [(c6H5)3p]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 Inorganic Chemistry, Volume II, H. Remy,
Elsevier Publishing Co. (1956);
Reactions 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;
i :~
~ RD-9366
3638
Organic Syntheses Via Metal Carbonyls, Vol. 1,
I. Wender and P. Pino, Interscience
Publishers (1968) Library of Congress
Catalog Card No. 67-13965;
The Organic Chemistry of Pal_adium, Vols. I and II,
P.M. Maitlis, Academic Press (1971) Library of
Congress Catalog Card No. 77-162937;
The Chemistry of Platinum and Palladium, F.R.
Hartley, Halsted Press (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
RD-9366
638
following: elemental alkali and alkaline earth metals;
basic quaternary ammonium, quaternary phosphonium or tertiary
sulfonium compounds; alkali or alkaline earth metal hydroxides;
salts of stron~ 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, sodiumr 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, benzyldimethyl-
amine, dioctylbenylamine, dimethylphenethylamine, l-dimethyl-
amino-2-phenylpropane, N,N,N', Nl-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. diisopropylmono-
ethylamine, 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 elass consisting of Groups IIIA, IVA, VA, VIA,
IB, IIB, VIB, VIIB and VIIIB, 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, iron, manganese, cobalt, mercury, lead, cerium, uranium,
g _
RD-9366
~E36~8
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,
-- 10 --
l'`' ,
, .~" ,
~ RD 9366
8~;38
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 VIIB, which catalyze the
oxidation of the Group VIIIB elements, i.e. ruthenium,
; rhodium, palladium. osmium, iridium or platinum in ~ `
the presence of oxgen, 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 he 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, can be employed with
good results. Presently preferred are oxygen pressures
within the range of from about 1/2 to 200 atmospheres.
,~
- 11 - '
~ 638 R~-9366
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 toe substantial absence of
oxygen, i.e. not as a redox co-catalyst component --
that the oxidant be present in amounts stoichiometric to ~rbonate
moieties; i.e., -0-C-O-, formed in the preparation of the aromatic
carbonates.
Any amount of redox co-catalyst conponent c~ be e~p~ed. 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 ~ the Group VnlB 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 ~o about
1000:1 or higher are effective; however, preferably ratios of
-L2-
~ , . . ....
RD-9356
36;~3
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 ln stoichio-
S metric amounts sufficient to form the desired aromatic mono- or
polycarbonate. In general, carbon monoxide pressures wlthln 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 ~00 atmospheres.
Any amount of solvent 9 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.
; 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 1I salicylate",
can be generically described by the following formula:
o
HO-Rb -C-O-RC
wherein Rb represents an aromatic radical wherein the hydroxyl
. .
RD-9366
11~l3638
radical is positioned ortho relative to the carboxylate, i.e.
o
-C-0- 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 separation and reco~ry of the salicylates is
~3 described in the Canadian Applica~ion Serial Number 300,56~,
of J.E. Nallgren, filed pp~ , /9~2
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
~ 15 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
Preparation of 4,4'-(a, a-dimethylbenzyl)diphenyl
carbonate using p-cumylphenol, carbon monoxide, diisopropyl-
monoethylamine, metallic palladium, and copper dibromide.
A reaction pressure vessel was charged with 2.211 g.
(10.43 mmol.) of p-cumylphenol, 0.126 g. (1.18 mmol.) of
palladium metal, i.e. palladium having an oxidation state of
-14 -
,, I, .
.. i ,, i . . .... . .
, . .
~ 3~ RD-9366
zero, 1.330 g. (10.31 mmol ) of diisopropylmonoethylamine,
1.110 g. (5.0 mmol.) of copper dibromide, 20 ml. of methyl-
enedichloride, and sufficient carbon monoxide to charge the
vessel to 66 psi. Subsequent workup showed t~e presence of
0.141 g. (6% yield) of 4,4'-(a, a-dimethylbenzyl)dimethyl-
benzyl)diphenylcarbonate of the formula
~ CH ~ 0-C-0 ~ CU3
EXAMPLE II
The preparation of 4,4'-(a,a-dimethylbenzyl)diphenyl
carbonate using bis(benzonitrile)palladium(II)dichloride.
The reaction medium contained 2.28 g. (10.46 mmol.)
of p-cumylphenol, 0.3 g. (0.22 mmol.) of bisbenzonitrile-
palladium(II)dichloride, 1.342 g. (10.42 mmol.~ of diisopropyl-
monoethylamine, 1.288 g. (5.78 mmol.) of copper dibromide,
20 ml. of methy~ne chloride, and sufficient carbon monoxide to
charge the vessel to 70 psi. The subject product yield was
11% of 4J4'-(a,a-dimethylbenzyl)diphenylcarbonate.
The number of carbonate moieties, i.e. -0-C-0- formed
per mole of palladium metal was 5.2, which hereafter is referred
to as the Group VIIIB "turnover value" of the reaction.
~ 6 ~ RD-~36
EXAMPLE III
.
Preparation of 4,4'-(a,a-dimethylbenzyl)diphenyl-
carbonate under carbon monoxide and oxygen pressure.
The reaction medium contained p-cumylphenol, bis-
(benzonitrile)palladium(II) dichloride, diisopropylmonoethyl-
amine, and copper dibromide in the following mole proportions:
100:2:15:8. Sufficient carbon monoxide was charged to the
vessel to raise the pressure to 31 psi and sufficient oxygen
was subsequently added to raise the pressure of the vessel to
a total pressure of 62 psi. The product yield was 8% of 4,
` 4'-a,a(dimethylbenzyl)diphenylcarbonate. The turn over value
: was 4.
EXAMPLE IV
Preparation of 4,4'-(~, a-dimethylbenzyl)diphenyl-
carbonate using palladium(I) monocarbonylmonobromide and 2,2,-
6,6,N-pentamethylpiperidine as a base.
The reaction vessel contained 2.12 g. (10.0 mmol.) of
p-cumylphenol, 1.55 g. (10.0 mmol.) of the 2,2,6,6,N-penta-
methylpiperidine, 2.233 g. (10.0 mmol.) copper dibromide, 0.1 g.
(0.5 mmol.) of palladium(I) monocarbonylmonobromide, and 20 ml.
of methylenechloride. The product yield was 0.60 g. ( 26 %) of
aromatic carbonate and 0.54 g. (18%) of mono-bromo-p-cumyl-
phenol. The turnover value was 5.4.
-16-
~ 863~ ~ 9366
EXAMPLE V
This procedure, not an ex~mple of this
invention, illustrates the 2ttempted preparation of
diphenylcarbonate employlng the teachings of Perrotti et al.
U.S. 3J346J468~ by contacting sodium phenoxide w~th carbon monox-
ide in the presence of pyrridine as a base.
The procedure involved the addition of 6.73 g. (0.05
moles) of copper dichlorideJ 50 ml. of pyridine, and 150 ml. of
N,N-dimethylformamide to the reaction medium. The resulting
mixture was cooled to -78 C. in a dry ice acetone bath. 11.6 g.
(0.10 moles) of sodium phenoxidP dissolved in 50 ml. of N,N-
dimethylformamide was slowly added to the reaction medium while
maintaining the temperature below -50 C. After all of the
sodium phenoxide has been added, the mixture was analyzed for
evidence of the formation of diphenylcarbonate at the following
temperatures. Less than -50 C., -30 C., -10 C., room tempera-
ture, ~70C. while carbon monoxide was slowly bubbled through
the reaction medium. ~as chromotagraphy of the reaction medium
during the entire reaction period showed no aromatic carbonate
formation and showed only the starting materials present within
the re~ction medium. From this experimental data, it was con-
cluded that teachings of the Perrotti et al. reference were
not applicable to reactions involving phenolic reactants.
In a preferred embodiment of my invention, set ou~ in
Examples V to XV, my process is carried out in the presence of
; oxygen and a molecular sieve. This embodiment~ which is the
~`86~ RD-9366
sub~ect matter of J.E. Hallgren's Canadian Patent Application
B Serial No. 3~) 6O~ filed ~rl~ 6J ~7~ ,
~- has been found to provide improved results and so is disclosed
also herein, although not essential to the utility of this in-
vention.
EXAMPLE VI
-
Preparation of 4,4'(~,a-dlmethylbenzyl)dipnenyl-
carbonate under carbon monoxide and oxygen pressure and in the
presence of a m~lecular sieve Type 4A --- a commercîal product
of Union Carbide Corporation of the general chemical formula
0.96+ 0.04 Na2O-l.00 A12O3 1.92 ~ 0.09 SiO2- x H20.
The reaction medium contained p-cumylphenol, bis-
(benzonitrile)palladium(II) dichLoride, diisopropylmonoethyl-
amine~ and copper dibromide in the following mole proportions:
100:2:16:8. Sufficient carbon monoxide was charged to the
vessel to raise the pressure to 31 psi and sufficient oxygen
was subsequently added to raise the pressure of the vessel to a
total pressure of 62 psi. The product yield was 31V/o of 4,4'-
a,a(dimethylbenzyl)diphenylcarbonate. As illustrated by this
example, inclusion of a molecular sieve significantly increases
the yield of aromatic carbonate as illustrated by the 400%
improvement in yield by this example contrasted with the yield
of Example III.
In a preferred embodiment of my invention set out in
Examples VII, VIII and XII my process is carried out through
the use of a manganese or cobalt complex cataLyst. The embodi-
t
-18-
,
;:
~638 RD-9366
ment, which is the sub~ect matter of J.E. Hallgren's Canadian
~ application.Serial Number 300, 6~ , filed
t9~ r~^/ G~ /97~ ~ has been found to provide improved
results and so is disclosed also herein, although not essential
to the utility of this invention.
E~AMPLE VII
Preparation of 4,4'~a~-dimethylbenzyl)diphenyl-
carbonate using p-cumylpheno~, carbon monoxide, the 2~2,6,6,N-
pentamethylpiperidine and a palladium bromide complex with
bis(benzoinoxime) 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-
bromide, 0.051 g. (0.00010 mole) of bis(benzoinoxime)manganese
(II), 0.155 g. (0.0010 mole) of the 2,2,6,6,N-pentamethylpiperi-
dine compound, 30 ml. of methyl chloride and 2.0 g. of a Lindy
Union Carbide 3A molecular sieve which had been activated 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%
of the sodium ions by potassium.
Carbon monoxideand 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%
conversion) of the 4,4'-(a~a-dimethylbenzyl)diphenylcarbonate.
After 44 hours, reaction product contained 1.23 g. (55% con-
- 19 -
,' .,. ~ .
, .
`l~ `` .
~ ~ 8 6 3 8 RD-9366
version) of the aromatic carbonate.
EXAMPLES VIII - XV
- Following the General Procedure of Example VII, set
out hereinbefore, a series of reactions were run employing
various oxidants for the preparation of aromatic carbonates in
the presence of molecular sie~es. Summarized in Table I here-
after are the reaction parameters and products, i.e. the mole
proportions of Group VIIIB element : oxidant : phenolic reactant :
base, the percent conversion of the phenolic reactant to aromatic
carbonate, the reaction time and the turnover value.
In all of the examples, the phenolic reactant was p-
cumylphenol and the base was 2,2,6,6,N-pentamethylpiperidine.
The Group VIIIB element in Examples VII, VIII, IX and XIII was
palladium (II) dibromide, and in Examples X, XI and XII was
palladium (I) monocarbonyl monobromide. The oxidant employed
in each example is tabulated in Table I. Example XIV was a
control run analogous to Example VII except that the Group VIII
element was excluded from the reaction and the reaction time
; was extended. It is consequently not an example of the
invention.
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EXAMPLE XV
Preparation of a polycarbonate of bisphenol-A by
contacting bis(4-hydroxyphenyl)propane-2,2, carbon monoxide,
manganese(II)bis(benzoinoxime), 2,2j6,6,N-pentamethylpiperidine,
palladium(II)dibromide, oxygenJ molecular sieve Type 3A and air.
A 50 ml. three-neck flask was charged with 4.56 g.
(20.0 mmol.) of bisphenol-A, 0.62 g. (4.4 mmol.) of 2,2,6,6,N-
pentamethylpiperidine, 0.06 g. (0.20 mmol.) of palladium(II)di-
bromide, 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 dimersj trimers, pentamers and
higher oligomers. An additional 0.06 g. (0.70 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% reco ery. This example
illustrates and demonstrates the utility of my catalytic pro-
cess in the preparation of polycarbonates of bisphenol-A.
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
j that other Group VIIIB metals, phenolic compounds, ligands,
oxidants, redox components and solvents as well as other reaction
conditions can be effected without departing from the scope of
the invention.
-22-
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