CA1108638A - Catalytic aromatic carbonate process - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

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 resulting aromatic mono- and polycarbonates are useful in the preparation of polycarbonates or as polycarbonates, per se, respectfully, which can be molded or formed into films, sheets, fibers, laminate, or reinforced plastics by conventional techniques.

Description

-~RD 9366 ~- 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 . ! .

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 .

~ ~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~ , ~' 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 ,~
~.

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 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 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 _ ~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, 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 ~ , . . ....

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 . .

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 ,, 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.

~ 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 , ;:

~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-,' .,. ~ .
, .

`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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P ~. :
h ~ u~ O o~ O O
~ ~ ' S

U~
a~ o : :
_ ~
~a8 ~

~' I O O u~ O O ul u~ O
. .. ;~':, U C '~

O C ~ O 0, o o o o o o " ~
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g.~41 h ~ ¦

~ C = =l o~
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X ~ ~ H X X X X X

, ,-, , ., ;,, ' ~ ' ' ,:, ' ~ 38 RD-9366 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.

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Claims (22)

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 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 result aromatic carbonate product.

9. The claim 1 process, wherein the phenol is p-cumylphenol, the base is 2,2,6,6,N-pentamethylpiperidine, the oxidant is oxygen, the Group VIIIB element is palladium in the form of palladium dibromide, and a redox catalyst for the oxidation of the Group VIIIB element is present.

10. The claim 1 process, wherein the Group VIIIB
element is palladium.

11. The claim 1 process, further comprising, after the preparation of the aromatic carbonate, separating at least a portion of any resulting Group VIIIB element, compound or complex from said carbonate, oxidizing at least a portion of said resulting Group VIIIB element, compound or complex and recycling at least a portion of the oxidized element, compound or complex in said aromatic carbonate process.

12. An aromatic polycarbonate process which comprises:
contacting an aromatic polyphenol 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.

13. An aromatic polycarbonate process which comprises:
contacting an aromatic bisphenol 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.

14. The claim 13 process, wherein R1 and R2 are methyl, and at least one of R3 and R4 is hydrogen.

15. The claim 14 process, wherein said base is a tertiary amine.

16. The claim 15 process, carried out in the presence of an inert solvent.

17. An aromatic polycarbonate process which comprises:
contacting 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 VIIIB, or a compound or complex thereof.

18. An aromatic monocarbonate process which comprises:
contacting 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, 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.

19. The claim 18 process, wherein Ra is selected from carbo- or heteromonocyclic, polycyclic or fused polycyclic radicals.

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

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

22. An aromatic monocarbonate process which comprises contacting 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 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.