CA1093575A - Aromatic carbonates - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

An aromatic carbonate process comprising contacting a phenol, carbon monoxide, a base, a Group VIIB element selected from ruthenium, rhodium, palladium, osmium, iridium or platinum having an oxidation state of plus one. 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

3.575 This invention relates to an aromatic carbonate process comprising contacting a phenol, carbon monoxide, a base, a Group~ element selected from ruthenium, I
rhodium, palladium, osmium, iridium or platinum having an oxidation state of plus one.
In Canadian patent application Serial Number 288,493 filed October 6, 1977 and Serial No. 300,634 filed April 6, 1978 to A.J. Chalk, commonly assigned herewith, it is disclosed generally that aromatic carbonates can be prepared by contacting a phenol, a base, carbon monoxide and a Group VIIIB element selected ~-from ruthenium, rhodium, palladium, osmium, iridium, or platinum having an oxidation state greater than zero.
Unexpectedly, I have found that when the Group VIIIB
element is employed at the first oxidation level greater than zero at the beginning of my aromatic carbonate process, the yields of aromatic carbonate are optimi~ed and that by-product undesirable side reactions such as the formation of aromatic salicylates are essentially or substantially avoided.
This invention embodies an axomatic carbonate process comprising contacting a phenol, carbon monoxide, a base, and a ~roup VIIIB element selected from ruthenium, rhodium, palladium, osmium, iridium or platinum having an oxidation state of plus one.
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 preparation of aromatic monocarbonates (Eq. 1) and polycarbonates (Eq. 2) may be much more complex:

~ RD 9369 Eq. 1 2nPd(CO)Cl + 2nR'OH + 2nR3N
+
2nPd + nR 2CO3 + 2nR3 Eq. 2 2nPd(CO)Cl + (n+l)R" ~OH)2 + 2nR3N

~-~ 2nPd~ + ~IO ¦ R"-OCO l R"-O~ + 2nR3N~CI + nCO

wherein R is an alkyl radical (including cycloalkyl), R' is an aryl radical, R" is an arene radical, and n is a number equal to at least 1.
The Group VIIIB element that can be employed is defined herein and in the appended claims as "the Group VIIIB element" and is any Group VIIIB element subject to the proviso that is selected from ruthenium, rhodium, palladium, osmium, iridium or platinum having an oxidation state of plus one, l.e. a first oxidation level greater than zero. The Group VIIIB element can be present in ionic, inorganic or organic compound or complex, etc. form. The Group VIIIB element can be employed in any form, e.g. oxide, halide, nitrate, sulfate, oxalate, acetate, carbonated, propionate, hydroxide - or tartrate form, etc.
B
r ~ 20 The Group~ elements can be employed in ' complex form, e.g. with ligands, such as carbon monoxide, nitriles, tertiary amines, phosphines, arsines, or stibenes, etc. Illustratively the complex forms are often represented by those skilled in the art as mono-, di-, or ; polynuclear forms. Generally, the dimeric or polymeric forms are considered to contain the Group VIIIB atoms bridged by ligands, halogens, etc. Preferably the Group VIIIB elements take the form of a homogeneous ~ ~q~ S7 ~ RD 9369 admixture, more preferably a homoyeneous solution, when 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(CO)Cl, Ru(CO)Br, Ru(CO)I, RuCl[P(C2H5)3]3, etc.; RhCl(CO)[P(C2H5)3]2, 3 C6H4)2, [Rh(CNC~3OC6H4)4]C1, [Rh(CNClCçH4) ]Cl [Rh(CO)2C1]2~ Rh2C12(C)2, Rh2(co)4c 2~ 2 4 2 Rh2(CO)4Br2, Rh2(CO)4I2, etc.; Pd(CO)Cl, Pd(CO)Er, Pd(CO)I, PdH(CO)Cl, PdH(CO)Br, Pd(C6I16)(H2O)Clo4, Pd2(CO)2Cl, [(H C ) N] PdBr4, K2Pd2(cO)2cl4r Na2Pd2( 2 4 Os(CO)2Cl, Os(CO)2Br, Os(CO)2I, Os(CO)4Cl, Os(CO)4Br, Os(CO)4I, etc.; Ir(CO)2Cl, Ir(CO)2Br, Ir(CO)2I, Ir(CO)3Cl, Ir(CO)3Br, Ir(CO)3I, IrCl(CO)[P(C6H5)3]2, etc; and Pt(CO)C]., Pt(CO)Br, Pt(CO)I, Na2E't2(CO)2C14, Na2Pt2(CO)2Br4

2 2( )2 4' The group VIIIB element compounds and/or complexes can be prepared by any method ~ell-known to those skilled in the art including the methods referenced in Reactions o;f_Transiti_n-Metal Complexes, J.P.
Candlin, K. A, Taylor and D. T. Thompson, Else-vier Publishing Co. (19Ç8) Library of Congress Catalog Card No. 67-19g55, amony others as well as those described in U. S. and ~areiyn technical journals and patents.
Any nuclearly hydroxy substituted aromatic compound can be used in my process and is defined hexein and in the appended claims as "a phenol". Illustratively the phenol or phenolic reactant can be described by the formula:

5~ ff~
~ 7~ RD 9369 : I. R~ OH) wherein Ra represents an aromatic radical wherein 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 e ~ ro~?o~o CyC/~ G
' Ra radical can be carbo- or horJ3~c~, polycyclic, or fused polycyclic, and can have two or more cyclic systems (monocylcic, polycyclic or fused polycyclic systems) which are connected to each other by single or double valence bonds, 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), naphthol, ortho-, meta-or paracresol, catechol, cumenolr xylenol, resorcinol, the various isomers of dihydroxy diphenyl, the various isomers of dihydroxynaphthalene, bis(4-hydroxyphenyl)propane-2,2, ~ ,~ '-bis(4,dihydroxy-3,5,3',5'-tetrachlorophenylpropane-2,2, 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:

R3 R1 ,R

II. ~IO -- ~ C ~ C ~ OH

~4 ~ 4 R R

~ 5~5 RD 9369 where Rl and R2 are hydrogen, C alkyl or phenyl, at least one of R 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-~" (BPA).
The process can be carried out in the absence of any s~lvent, e.~. where the pheno]ic reactant acts as both a reactant and sol~ent, however preferably is carried out in the presence of a solvent, and more preferably solvents of the general class: methylene chloride, ethylene dichloride, chloroform, carbontetrachloride, tetrachloroethylene, nitro-methane, hexane, 3-methylpentane, heptane, cyclohexane, methylcyclohexane, cyclo hexane, isooctane, p-cymene, cumene declain, toluene, benzene, diphenylether, dioxane, thiophene, dimethylsulfide, ethylacetate, tetrahydrofuran, chlorobenzene, anisol, bromobenzene, o-dichlorobenzene, methylformate, - 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 which will dissolve the phenolic reactant. Representative of basic species which can be employed are the following. elemental alkali and alkaline earth ~ , basic quarternary ammonium, quarternary phosphonium or tertiary sufonium compounds; alkali or alkaline earth metal hydroxides; salts of strong bases and weak organic acids; primary, secondary or tertiary amines;
etc. Specific examples of the aforementionéd are sodium, potassium, magnesium metals, etc.; quaternary ammonium hydro-xide, tetraethyl phosphonium hydroxide, etc.; sodium,potassium lithium, and calcium hydroxide; quaternary phosphonium, tertiary sulfonium, sodium, lithium and barium ~7~

carbonate, sodium acetate, sodium benzoate, sodium methylate, sodium thiosulfate sodium compounds, e.g., sulfide, tetrafulfide, cyanide, hydride and borohydride, potassium fluoride, methyl-amine, isopropylamine, r,lethylethylamine, allylethylamine, ditert-butylamine, dicyclohexylamine, diben~ylamine, tert-butylamine, allyldiethylamine, benzyldimethylamine, diactylchlorobenzylamine, dimethylphenethylamine, l-dimethyl-amino-2-phenylpropane, propanediamine, ethylenediamine, N-methylethylenediamine, N,N'-dimethylethylenediamine, N,N,N'-tritert-butylpropanediamine, N,N',N', N''-tetra-methyldiethylenetriamine, pyridine, aminomethylpyridines, pyrrole, pyrrolidine, piperidine, 2,2,6,6-N-pentamethyl-piperidine, imidazole, etc. Especially preferred bases are sterically hindered amines, e~. diisopropylmonoethylamine, 2,2,6,6,N-pentamethylpiperidine, etc.
Any reasonable amount of base can be employed.
In general, effecitve mole ratioc; of base to Group VIIIB
elements are within the range of from about 0.000001:1 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 l:l enhances both the reaction rate and the yield of aromatic carbonate.
- Any reasonable amount of Group VIIIB element can be employed. For example, Group VIIIB element to phenol mole proportions within the range of from about 0.001:1 or lower to about lO00:1 or higher are effective, however, preferakly ratios of from o.l:l to 10:1, and more preferably at least l:l are employed in order to insure that optimum conversion of the phenol to aromatic carbonate occurs.
Any reasonable amount of carbon monoxide can be employed. Preferably the process is carried out under ~ 57~ RD 9369 positive carbon monoxide pressure, i.e., where carbon monoxide is present in stoiciometric amounts sufficient to form the desired aromatic mono- or polycarbonate. In general, carbon monoxide pressures within the range of from about 1/2 to about 500 atmospheres, or even higher, can be employed with good results, Present preferred are CO pressures within the range of from 1 to 200 atmospheres.
An reasonable reaction temperature can be employed In general, optimum reaction temperatures are 0C. or even lower to 200C. or even higher and more oftent 0C. to 50C.
Any reasonable reaction time period can be employed.
Generally optimum reaction periods are about 0.1 hour or even less to about 10 hours or even more.
Any amount of solvent, preferably inert, can be employed. 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.
Following the procedures of my invention described herein, aromatic carbonates are formed in the substantial absence of aromatic salicylates, i.e. aromatic salicylates being present in amounts which cannot be analytically deter-mined according to the procedures described or employed herein in the analysis of the resulting aromatic carbonate reaction products.
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 ctherwise specified, all parts are by weight and the reaction products were verified by infrared spectrum, C-13 nuclear magnetic resonance and mass spectometry.

57~i EXAMPLE I
. _ Preparation of diphenyl carbonate using p~enol, also known as hydroxybenzene, carbon monoxide, diisopropylmono-ethylamine and poly[palladium(I) monocarbonyl chloride].
Polypalladium(I) monocarbonyl chloride was prepared by modification of the literature procedure of W. Schnabel and Eo Kober, J. Organomet. Chem. 19, 455 (1969). The prGcedure involved the addition of 0.77 g. (2.0 mmol.) of bis(benzo-nitrile)palladium(II) dichloride to 200 mul. of chloroform.
Carbon monoxide was passed through the resulting solution slowly until a yellow precipitate formed and the color of the organic phase was discharged. The mixture was ~iltered and -the precipitate dried at room temperature in vacuo. Subsequent work-up and analysis showed the presence of 0.25 g. (72%
yield) of poly[palladium(I) monocarbonyl chloride] of the empirical formula poly[Pd(CO)Cl]. A mixture containing the amount of 0.094 g (1.0 mmol.) of phenol, 0.26 g. (2.0 mmol.) of diisopropylmonoethylamine and 0.25 g. of palladium(I) mono-carbonyl chloride was saturated with carbon monoxide and a black precipitate formed. GC analysis of the reaction mixture showed the presence of 0.11 g. ~96% yield) of diphenyl carbonate of the formula: O
~ O-C-O <~

EXAMPLE II
_ Preparation of 4,4'-dimethyldiphenyl carbonate using 4-cresol as the phenolic reactant.
A vessel was charged with 0.30 g. (1.8 mmol.) of poly[Pd(CO)Cl] prepared in accord with the procedure of Example 1 above, 0~3~3 g. (3.54 mmol.) of 4-cresol~ 0.46 g. (3.54 mmol.) of diisopropylmonoethylamine and 5 ml. of meth~lene chloride.
The reaction procedure described in Exampl I was followed.

~ .q3~7~ RD 9369 Subsequent work-up and analysis showed the presence of 0.13 g.
(62% yield) of bis-_-tolyl carbonate, also known as 4,4'-di-methyldiphenyl carbonate, of the formula:

3(~-- O-C-o__~CH3 EXAMPLE III
.
Preparation oE bis( 4 , d -dimethylbenzyl) diphenyl carbonate using p-cumylphenol as the phenolic reactant.
0.26 g. (1.53 mmol.) of poly[Pd(CO)Cl], poly[pal-ladium(I) monocarbonyl chloride] prepared as in Example I, 0.65 g. ~3.06 g. (3.06 mmol.) of p-cumylphenol, 0.40 g.
(3.06 mmol.) of diisopropylmonethylamine and 10 ml. of methy-lene chloride were contacted with carbon monoxied as described in Example I. Subsequent work-up and analysis showed the presence of 0.59 g. (86% yield) of bis(_-cumyl-phenyl)carbon-ate also known as 4,4'_(Ct ,d -dimethylbenzyl)diphenyl carbon-ate, of the formula:

~C --(C~ C O ~ 3 EXAMPLE IV
Preparation of 4,4'-dichlorodiphenyl carbonate using

4-chlorophenol as the phenolic reactant.
0.26 g (1.53 mmol.) of poly[Pd(CO)Cl], 0.39 g. (3.06 mmol.) of _-chlorQphenol, 0.39 g. (3.06 mmol.) of diisopropyl-monoethylamine and 5 ml. of methylene chloride were contacted with carbon monoxide as described in Example I. Subsequent work-up and analysis showed the presence of 0.151 g. (35%
yield) of bis(_-chlorophenyl) carbonate, also known as 4,4'-di~
chlorodiphenyl carbonate of the formula:

Cl~C~- -11---~C~l ~3~57~i EXAMPLE V
Preparat~on of 4j4'-dlmetho2cydiphenyl caxbona~e using p-methoxy phenol as the phenolic reactant.
0.31 g. (1D8 mmol.~ poly[Pd(CO)C13, 0.45 g ~3.6 mmol.) of P-methoxyphenol~ 0.47 gO (3.6 mmol.) of diisopropylmonoethyl-amine in methylene chloride were contacted with carbon monoxide as descrlbed in Examp~e I. Subsequent work-up and analysis showed the presence of 0.11 gO (45% yield) of bis(p-metho~yphenyl)-carbonate, also known as 4,4'~dimethoxydiphenyl carbonata, 0.09 g.
(40% yield) o~ 4,4'-dimethoxy-2,2'-bisphenol, and 0002 g. (13%
yield) of 4-metho~y-2~6-bis(2-hydro~y-5-methoxyphenyl)phenol of the formulas, raspectively:

3 ~ O C~ ~ O~CH3 OH qH

- ~ , and OH OH OH
~ j EXAMPLE VI
Preparation o~ p~cumylphenyl(phenyl) carbonate and bis(p-cumylphenyl) carbonate using a mixture of p cumylphenol and phenol as the phenolic reactants.
0.31 grams (1.8 mmol.) o~ poly[Pd(C03Cl], 0.39 g. ~1 82 7~i mmol,) of ~-cumylphenolJ 0~17 g. (~8 mmol.) of phenol, 6 ml. of me~hylene chloride, 0.47 g ~3 64 mmol.~ o~ diisopropylmonoethyl-amine were satur~ted with carbon monoxide during 3-hour reaction period. Subsequent work~up and analysis showed the presence o 0.19 ~rams (45% yield) o bis(p-cumylphenyl) carbonate and 0.14 (45~/~ yield) o~ p-cumylphenyl(phenyl) carbonate and a trade (estimated 2%yield) of diphenyl carbonateO

EXAMPLE VII
Preparation of bls(p-cumylphenyl) carbo~a~e and p-cumylphenyl)p~chlorophenyl) carbonat:e using a mixture of ~-cumylphenol and ~-chlorophenol as the phenolic reactants.
0.20 grams (1.2 mmol.3 of poly[Pd(CO)Cl~, 0.25 gO (1.2 mmol,) of p-cumylphenol, 0.15 grams (1.2 mmol ) of p-chlorophenol, ~-~ 0~30 g. (2.36 mmol ) of diisopropylmonoethylamine and 3 ml. of methylene chloride were contacted with carbon monoxide as in ~xample I. Subsequent work-up and analysis showed the presence of 0~11 grams (3% yield~ o bls(p-cumylphenyl) carbonate and 0.088 grams (40% yield) of p-cumylphenyl(p-chlorophenyl) carbon-ate.

EXAMPLE VII~
Preparation of a mix~ure o~ bis(p-methoxyphenyl) carbonate, 4,4'- dlmethoxy- 2,2'-bisphenol and p-cumylphenyl(p-methoxyphenyl) carbonate by contacting a mixture of p-cumylphenol and p-methoxyphenol with carbon mDnoxide carr~ed out in the pres~nce of poly[Pd(CO)Cl].
0.17 grams (1.0 mmol.) of [Pd(CO)Cl], 0.42 g. (2 0 RD-93~9 mmol.) of p-cumylphenyl, 0.24 g, (2.0 mmol.) of p-methoxyphenol, 0,52 g. (4.0 mmolO) of diisopropylmonoethylamlne, and 5 ml. of methylene chloride were contacted w1th ~arbon monaxide a3 in -Example I. Subsequent work-up and analysis showed the presence of 0,03 g. (25%yield) of bis(p-methoxyphenyl) carbonate, 0.05 g. ~25% yield) of 4,4'-dimethoxy-2,2'-bisphenol, and 0.055 &.
~50% yield) of p-cumylphenyl(p-methoxyphenyl) carbonate.

EXAMPLE IX
_ _ Preparation of a polycarbonate of bisphenol-A by contacting bis(4-hydroxyphenyl)propane-2,2~ carbon monoxide9 diisopropylmonoethylamine and poly[palladium~I) monocarbonyl chloride].

A 50 ml. 4-neck resin kettle fitted wlth a gas addition type hollow turbine stirrer, septum cap and gas outlet was charged with 5.15 g. (~.030 mol.~ of polylpalladium(I) mono-~ 3~7~

carbonyl chloride] of the empirical formula ~Pd~CO~Cl~x, 3.29 g.
(0.014 mol ) of bisphenol-A and 25 ml. of methylene chlorlde.
Carbon monoxide was bubbled through the resulting slurry snd 7.84 g~ (0,061 mol.) of dlisopropylmonoethylamine wa~ addedO The reaction mixture turned black immediately. Passage of the carbon monoxlde through the reaction media was continued ~or about lS
hours. The resulting reactlon products were filtered, the filtrate w~s con~entrated and precipitated by addition to 300 ml. o~
vigorously stirred methanol. The resulting polymer was collected by filtration, redissolved~ filtered and reprecipitated.
Polymer was dried overnight in vacuo at 100 C. Gel permeation chromotography (GPC) analysis of the reaction mixture showed the presence of a polycarbonate o bisphenol-A containing recurring uni~s o the ~ormula:

~ ~ ~

wherein n is an intager averaging at least about 6. A resume of react~on conditions and products describing phenolic reactant, bisphenol (-OH) group to palladium mole ratio, yield of poly~
carbonate on a weight basis, Mn number average molecular weight~
Mw weight average molecular weight, ~W/Mn, n - average degree of polymerization is set out in Table I which follows:

~935 7~ RD 9369 TABLE I
Mole Phenolic Ratio Yield M M ~ /M
React~nt OH:Pd ~ _ n w Mw n n BPA(l) 1 5(2) 1714(3) 2053(3) 1 20(3) 6 (1) bisphenol-A
(2) % recovered by weight after precipitation o a 5% CH2Cl2 solution into methanol (3) GPC data using polystyrene standards in CH2Cl~

EXAMPLE X
Preparation of a polycarbonate of bisphenol-A using a monocarbonate oligomer of bii~(4-hydroxyphenyl)propane-2,2 as the phenolic reactant.
The prepar~tions of the poly[palladium(I)monocarbonyl chloride] and the polycarbonate were conducted as set out in Exampl~ I and rx, re~ectively, exceptas noted hereafter, There~tion medium contained 0.076 g. (0.45 mmol.) of poly[palladium(I)monocarbonyl chloride], 0.087 g. (0.1~ mmol.) of bisphenol A monocarbonate, 3 ml. of methylene chloride and 0.12 g, ~0.90 mmol.) of diisopropyl-monoethylamine. &PC analysis o~ the reaction product mixturedetermined the presence of a polycarbonate of bisphenol~A
containing recurring units of the Example IX formula. A resume of the reaction is set out in Table II ~hich follows:

TABLE II
Mole Phenolic Ratio Yield Reactant OH:Pd ~ _ n_ w~ _ _ w/ n n BPA-C-BPA(l) 0.8 50( ) 1773( ) 2501(3~ 1(3) 6 i ...... . ..

~AO ~a 3 S7 S

~ "' , (1) (H ~ C

~2~ & (3) as in Example IX, Table I
, ~
EXAMPLE XI
Pr~para~ion o a polycarbonate o~ blsphenol-A us~ng S 2~2,6,6,N-pentamethylpiperidine as a base.
The preparations of the poly~palladium(I~monocarbonyl chloride] a~d the polycarbonate were conducted ~s set out ln Ex~mpl~ Iand IX,r~ctively, except as noted herea~ter. Ihereac8on medium contained 2.669 g. (15.71 moles) of poly[pallsdium(I)monocarbonyl chloride]~ 1, 3~5 gr (5.89 mmol.~ of bisphenol-A, 15 ml. of methylene chlorlde and 3.659 g. (23.56 mmol.) of 2,2,6,6,N-pentamethylpiperidine. The reaction products were concentrated in 100 ml, o~ methanol and dried at 80D C. GPC analysis of the -reaction mixture show the presence o~ 1.42 g. (95% yie~d~ of a polycarbonate of bisphenol-A containing the recurring units of the Example IX formula. A resume of th~ reaction is set out in Table III.

TABLE III
Mole 20Phenolic Ratio Yield - - -_ eactant OH:Pd ~L~ Mn Mw M /M
BiSpheno~A(l) 0.75 95(2) 500o(3) 9000(3) 1.8~3) 20 (1) & (2) as in Example IX, Table I
(3) GPC data using polycarbonate standards in tetrahydrofuran ;~

RD-936g EXAMPLE XII
Prepara~ion of a polycarbonate of bisphenol-A using poly[p~lladium(I)monocarbonyl ~romide], The preparations of poly[palladium(I)monocarbonyl bromide] and the polycarbonate were conducted ais set out in ExsmplesI and IX, respectively, except as noted hereafterO
The poly[palladium(I)monocarbonyl bromide] procedure lnvolved the use of 0.77 g. (2.0 mmol~) of bisbenzonltrile -palladium(II) dibromide, and resulted in a 49% yield o~ poly-[palladium(I)monocarbonyl bromide]. The reaction mediumcontained 2.00 g. (9.3 moles) of poly[palladium(I) monocarbonyl bromide], 0.96 g. (4.2 mmol.) of bisphenol-A, 20 ml. of methylene chloride and 2.89 g. (18.6 mmol.) of 2,2,6,6,N-pentamethyl-piperidine. The reaction products were concentrated in 100 ml.
lS of methanol and dried at 60 C. GP(' analysis showed the presence o~ 0,97 gO (91% yield) of a polycarbonate of bisphenol-A contain-ing the recurring units of the Example IX formula. A resume of the reaction is set out in Table IV.

TABLE IV
Mole Phenolic Ratio Yield M M M /M
Reactant OH:Pd ~wt./%2 n w w n n Bi henol A(l) 0 9 91(2) 8000(3~ 16,000( ~ 2.0 32 (1~ & (2) as in Example IX, Table I
(3) as in Example VI~ Table III

EXAMPLE XIII

Preparation of a polycarbonate of bisphenol A using the " " , " . ~ . " " . ~

~ 5~ RD 9369 polycarbonate product of Example XII as the phenolic reactant.
The preparations of the poly[palladium(I) mono-carbonyl chloride] and the polycarbonate was conducted as set out in Examples I and IX, respectively, except as noted here-after. The reaction medium contained 0.086 grams, (0.40 mmol.) of poly[palladium(I) monocarbonyl chloride], 0.500 grams of the polycarbonate product of Example XII, 16 ml. of methylene chloride and 0.124 g. (0.80 mmol.~ of 2,2,6,6,N-pentamethyl-piper~dine. The reaction products were concentrated in 100 ml.
of methanol and dried at 80C. GPC analysis showed the presence of 0.43 g. (86% yield) of a polycarbonate of bisphenol-A con-taining the recurring units of the Example IX formula. A
resume of the reaction is set out in Table V:
TABLE V ~-Mole Phenolic Ratio Yield M M M /M
Reactant OH:Pd (wt./T) n w w' n n _ _ .. _ _ . ... . .
Bisphenol-At ) nOd. 86 11,000(3) n.d. n.d. 44 (1) polycarbonate of bisphenol-A of Example XII
(2) & (3) as in Example X, Table 1 n.d. not determined As illustrated by the preparation of polycarbonates of bisphenol-A in Examples IX to XIII above, in general the aromatic polycarbonates that can be prepared by my process are oligomeric or polymeric and have an intrinsic viscosity range of as high as 1.5 or even higher decilieters per gram (dl./g.) as measured in methylene chloride. Especially useful are polycarbonate resins which are generally suited to the preparation of films, sheets, fibers~ laminates or reinforced plastlcs (eAg, for insula~ing or protective coating applications) by conventional technlque~ which havP an intrinsic viscos~ty of from about 0.35 to about 0.7 dl~/g.

~XAMPLE XIV
_. . .
Preparation of diphenylcarbonate using bis(tetrapropyl-ammonium~dicarbony~ tetrachloroplstinite(I).
-The bi (tetrapropylammonium~dicarbonyl tetrachloro-platlni~a(I) was prepared by tha procedure o~ Gogg~n and Goodfellow, J. Chem. Soc. (Dalton~ ~1973) 2355. The reaction vessel was charged with 0.48 g. (0.5 mmol.) of bis(tetrapro~yl-ammonlum)dicarbonyl tetrachloroplatinite~I), 0.38 g. (4.0 mmol.) of phenol, and 7 m~. of methylene chloride. Carbon monoxide was bubbled through the mixture and 0.62 g. (4.0 mmol.) of 2,2,~6,6,N-pentamethylpiperidine was added. Subsequent work and analysis showed the presence o~ diphenylcarbonate estimated at a 2% yield.
As illustrated by the foregoing Examples, aromatic carbonates are readily formed in the substantial absence of `~
aromatic salicylates wherein the Group VIIIB element is employed in an oxidation state of plus one prior to forming a reaction mixture containing any of the other reactants. These examples illustrate one of preferred methods, i.e. a !'best mode", of practicing my invention.
Further~ another process parameter of my invention comprises using a controlled reaction process sequence whereby an aromatic carbonate is readily formed in the substantial absence of an aromatic salicylate wherein the Group VIIIB

~ 5 75 RD 9369 employed at the beginning of the aromatic carbonate process has an oxidation state greater than plus one. This process requires a carbonate preliminary reaction admixture, i.e.
"carbonate PRM" containing a phenolic reactant and a Group VIIIB element having an oxidation state greater -than plus one, be contacted with carbon monoxide for a substantial period of time, e.g. 5, 10, 20, 60 or more minutes, prior to the addition of a base thereto.
EXAMPLES XV - XVIII
Preparation of diphenylcarbonate using a carbonate preliminary reaction admixture, i.e. phenol, carbon monoxide and bis(benzonitrile)palladium(II)dichloride and regulating relative to time the order of addition of a base, e.g. diisopropylmonoethylamine, to the preliminary reaction admixture.
A series of independent reactions were carried out wherein a preliminary reaction admixture, i.e. a "PRM", was contacted with a base, i.e. diisopropylmonoethylamine,

5, 20, 60 and 120 minutes after the PRM was initially contacted with carbon monoxide. A control run was carried out with base being added at zero minutes. e.g. essentially simultaneously with the formation of the PRM. Three hours after the combination of the PRM ingredients, the resulting reaction products were analyzed and the relative proportions of diphenylcarbonate and phenylsalicylate were determined.
Summarized in Table I are the reaction parameters and products r i.e. the time of addition of the base to the PRM
and -the resulting reaction products, i.e. the diphenyl-carbonate and the phenylsalicylate.

~3575 RD 9369 TABLE I

Base ~.
Example Runi Addition Relatlve Proportions ~ No.

Control 1.* 0 0.05 : 99.95 XV 2. 5 0.~ 99.75 XVI 3~ 20 5 95 XVII 4. 60 50 : 50 XVIII 5. 120 :100 : 0 *-control run As ~llustrated by this example, the time and "Qrder o addition" sequence;, ~.e~ tlme and order of addition of base to a carbonate PRM in the practice of my process significantly effects the relative proportions and accordingly the yield of diphenyl-carbonate. - :
In the practice of my process, the Group VIIIB elements after sepsration from the resulting reaction products can be oxidized to any suitable oxidation state, and can be re-employed, that is, recycled in the 3:romatic carbonate process described herein.

Althiough the above e~iamples have illustrated varlous modiflcations and changes that can be made in the ci3rrying out of my process~ it will be apparent to those skilled in the art that o~her Group VIIIB metals, phenolic compounds, ligands, oxidants, redox component6, drying agents and solvents as well as other : reaction conditions can be effected without departing from the scope of the inventionn " . . " . 1~ i ! , . ., ~

Claims (23)

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

1. A process for the formation of an aromatic carbonate with the suppression of concomitant salicylate formation which comprises contacting a phenol with carbon monoxide, a base, and a Group VIIIB element selected from ruthenium, rhodium, palladium, osmium, iridium or platinum having an oxidation state of plus one.

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

3. The claim 1 process, further comprising an initial step of contacting a Group VIIIB element selected from ruthenium, rhodium, palladium, osmium, iridium, or platinum having an oxidation state of at least plus two with carbon monoxide.

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

5. The claim 1 process, wherein said element is associated with a carbonyl group.

6. The claim 1 process, wherein said element is associated with a halide.

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

8. The claim 1 process, wherein methylene chloride is employed as a solvent, the base is disopropylmonoethylamine, the phenol is a phenol, and Group VIIIB element is polypalladium-(I)monocarbonyl chloride.

9. The claim 1 process, wherein methylene chloride is employed as a solvent, the base is diisopropylmonoethylamine, the phenol is bis(4-hydroxyphenyl)propane-2,2 and the Group VIIIB element is polypalladium(I)monocarbonyl chloride.

10. The claim 1 process, wherein methylene chloride is employed as a solvent, the base is 2,2,6,6,N-pentamethylpiperidine the phenol is bis(4-hydroxyphenyl) propane-2,2, the Group * element is polypalladium(I)mono-carbonyl bromide.

11. The claim 1 process, wherein methylene chloride is employed as a solvent, the base is 2,2,6,6,N-pentamethyl-piperidine, the phenol is a phenol, the Group * element is platinum in the form of bis(tetrapropylammonium)dicarbonyl-tetrachloroplatinite(I).

12. The claim 1 process, further comprising, after the preparation of the aromatic carbonate, separating at least a portion of any resulting Group * element or compound from said carbonate, oxidizing at least a portion of said resulting Group * element or compound to an oxidation state greater than zero, and recycling at least a portion of said oxidized element in said aromatic carbonate process.

13. A process for the formation of an aromatic poly-carbonate with the suppression of concomitant salicylate formation which comprises contacting an aromatic polyphenol with carbon monoxide in the presence of a base and a Group * metal selected from the class consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum having an oxidation state of plus one.

14. A process for the formation of an aromatic polycarbonate with the suppression of concomitant salicylate formation which comprises contacting an aromatic bisphenol of the formula:

, * VIIIB

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 in the presence of a base and a Group VIIIB metal selected from the class consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum having an oxidation state of plus one.

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

16. The claim 15 process, wherein the base is a tertiary amine.

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

18. A process for the formation of an aromatic polycarbonate with the suppression of concomitant salicylate formation which comprises contacting an aromatic bisphenol of the formula:

with carbon monoxide in the presence of a base and a Group VIIIB, metal selected from the class consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum having an oxidation state of plus one

19. A process for the formation of an aromatic monocarbonate with the suppression of concomitant salicylate formation which comprises contacting an aromatic phenol of the formula:

where Ra represents an aromatic radical wherein the -OH radical is attached directly to an aromatic ring carbon atom and x is the number 1, with carbon monoxide, a base, and a Group VIIIB
element selected from the class consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum having an oxidation state of plus one.

20. The claim 19 process, wherein Ra is selected from carbocyclic, polycyclic or fused polycyclic radicals.

21. The claim 20 process, wherein the base is a tertiary amine.

22. The claim 21 process, carried out in the present of an inert solvent.

23. A process for the formation of an aromatic monocarbonate with the suppression of concomitant salicylate formation which comprises contacting a phenol of the formula:

, with carbon monoxide, a base, and a Group VIIIB element selected from the class consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum having an oxidation state of plus one.