CA1108637A - Catalytic aromatic carbonate process - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
An improved catalytic aromatic carbonate process which comprises contacting in the presence of a drying agent a phenol, carbon monoxide, an oxidant other than an in addi-tion .alpha. oxygen, a base, and a Group VIIIB element selected from ruthenium, rhodium, palladium, osmium, iridium or platinum. The resulting aromatic mono- and polycarbonates are useful in the preparation of polycarbonates or as poly-carbonates per se, respectfully, which can be molded or formed into films, sheets, fibers, laminates or reinforced plastics by conventional techniques.

Description

~ 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 ~ ~ .

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 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 , ~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 ~

! RD-9368 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 ....
`'~'.

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 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, .

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' '';~

.''' ' ~

. :: ", ' ' . ~
''' :. ' 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 ~, . ..

`' :

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 ~ ,, .

~ 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 ~D-9368 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:

. .

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 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.

. ;,, ~

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 ~ ;

IX. ~ O;Co~-O
CH=N NH N=CH
1/ \t (CH2)3 (CH2)3 X. ~o-cO~-o~ .
CH=N IN=CH

, ~ .

~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 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:
. .

' ~o_c_~ . '~

,~ 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 ~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.
..... . , , . . . . . ~

. , - : -' ', ~' : - ~ :; ,, `: ..

- .,. ~ --- : :

~ ~ 86;~
a ~ Ln ~r ~ ~ o ~ ~ U~ o o s~
E~
_ ~D ,~ .~ ~
a) ~ ~ h 1~- 0 ~ ~ ~D
0 Ei rq o~
s~ ~ u~ o o ~ o ~ O a ~ O
P~) ~ O
u~ o oIn O O Lr) ~ O
0 ~ ~ ~
m : ..

O
O

m ~ u~
~ ~ o ~ O O
E~ ~0 ~ ~ ~ ~ ,~
IY;

~H
& ~ ~ ~~ ~~1 ~1 ~ O

~ O OS~ ~1 0 ~ ~ ~m o ~ ~
~ O OH ~ ~1 0 U R R~ h ~ ~: R
X H HO~ H ~ 0 H
O H H,~ H H 0 ~ H

a~
~ H HH
x0 æ ~ ~ ~ H X H
~3 ~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 _ . ,, ~

Claims (26)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. An aromatic carbonate process which comprises:
contacting in the presence of a drying agent a phenol with carbon monoxide, a base, a Group VIIIB element selected from the class consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum, and an oxidant having an oxidation potential more positive than that of said selected Group VIIIB element, said oxidant being an element selected from the class consisting of Groups IIIA, IVA, VA, VIA, IB, IIB, VIB, VIIB and VIIIB, or a compound or complex thereof.

2. The claim 1 process, wherein said Group VIIIB
element is present in an ionic form.

3. The claim 1 process, wherein said base is a sterically hindered amine.

4. The claim 1 process, wherein said Group VIIIB
element is associated with a carbonyl group.

5. The claim 1 process, wherein said Group VIIIB
element is associated with a halide.

6. The claim 1 process, wherein said Group VIIIB
element is coordinated with a ligand selected from the class consisting of an arsine, a stibine, a phosphine, a nitrile and a halide.

7. The claim 1 process, wherein said Group VIIIB
element is associated with an inorganic halide compound.

8. The claim 1 process, further comprising separating at least a portion of resulting aromatic carbonate product.

9. The claim 1 process, wherein said drying agent is a molecular sieve.

10. The claim 1 process, wherein said oxidant is a manganese or a cobalt complex.

11. The claim 1 process, wherein the phenol is p-cumylphenol, the base is 2,2,6,6N-pentamethylpiperidine, the oxidant is bis(benzoinoxime)manganese(II) and air, the Group VIIIB element is palladium in the form of palladium dibromide, and the drying agent is a molecular sieve.

12. The claim 1 process, wherein the Group VIIIB
element is paliadium.

13. The claim 1 process, wherein the phenol is bis(4-hydroxyphenyl)propane-2,2, the base is 2,2,6,6,N-pentamethyl-piperidine, the oxidant is bis(benzoinoxime)manganese(II) and oxygen, the Group VIIIB element is palladium in the form of palladium(II)dibromide, and the drying agent is a molecular sieve.

14. The claim 1 process, wherein the base is 2,2,6,6,N-pentamethylpiperidine, the oxidant is bis(benzoinoxime)manganese(II) and oxygen, the Group VIIIB element is palladium in the form of palladium(II)dibromide, and the drying agent is a molecular sieve.

15. The claim 1 process, wherein the oxidant is a cobalt chelate complex of the formula

16. An aromatic polycarbonate process which comprises:
contacting in the presence of a drying agent an aromatic poly-phenol with carbon monoxide, a base, a Group VIIIB element selected from the class consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum, and an oxidant having an oxidation potential more positive than that of said selected Group VIIIB element, said oxidant being an element selected from the class consisting of Groups IIIA, IVA, VA, VIA, IB, IIB, VIB, VIIB and VIIIB, ox a compound or complex thereof.

17. An aromatic polycarbonate process which comprises:
contacting in the presence of a drying agent an aromatic bis-phenol of the formula:
where independently each R1 and R2 is hydrogen, C1-4 alkyl or phenyl and independently each R3 and R4 is hydrogen or C1-4 alkyl, with carbon monoxide, a base, a Group VIIIB element selected from the class consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum, and an oxidant having an oxidation potential more positive than that of said selected Group VIIIB
element, said oxidant being an element selected from the class consisting of Groups IIIA, IVA, VA, VIA, IB, IIB, VIB, VIIB and VIIIB, or a compound or complex thereof.

18. The claim 17 process, wherein R1 and R2 are methyl, and at least one of R3 and R4 is hydrogen.

19. The claim 18 process, wherein said base is a tertiary amine.

20. The claim 19 process, carried out in the presence of an inert solvent.

21. An aromatic polycarbonate process which comprises:
contacting in the presence of a drying agent an aromatic bisphenol of the formula:
with carbon monoxide, a base, a Group VIIIB element selected from the class consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum, and an oxidant having an oxidation potential more positive than that of said selected Group VIIIB
element, said oxidant being 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.

22. An aromatic monocarbonate process which comprises:
contacting in the presence of a drying agent an aromatic phenol of the formula:
Ra? OH)x where Ra represents an aromatic radical, the -OH radical is attached directly to an aromatic ring carbon atom and x is the number 1, with carbon monoxide, a base, a Group VIIIB
element selected from the class consisting of ruthenium, rhodium, palladium, oxmium, iridium and platinum, and an oxidant having an oxidation potential more positive than that of said selected Group VIIIB element, said oxidant being an element selected from the class consisting of Groups IIIA, IVA, VA, VIA, IB, IIB, VIB, VIIB and VIIIB, or a compound or complex thereof.

23. The claim 22 process, wherein Ra is selected from carbo- or heteromonocyclic, polycyclic or fused polycyclic radicals.

24. The claim 23 process, wherein said base is a tertiary amine.

25. The claim 24 process, carried out in the presence of an inert solvent.
26. An aromatic monocarbonate process which comprises:
containing in the presence of a drying agent a phenol of the formula:
with carbon monoxide, a base, a Group VIIIB element selected from the class consisting of ruthenium, rhodium, palladium osmium, iridium and platinum, and an oxidant having an oxidation

Claim 26 continued:
potential more positive than that of said selected Group VIIIB
element, said oxidant being an element selected from the class consisting of Groups IIIA, IVA, VA, VIA, IB, IIB, VIB, VIIB and VIIIB, or a compound or complex thereof.