CA1231971A - Process for preparing aryl amines - Google Patents

Abstract

ABSTRACT
A process for preparing an unsymmetrical, substituted di-tertiary amine comprising reacting a di-secondary amine having the general formula R2-HN-R1-NH-R3 wherein R1 is a polyarylidene group, a polyarylether group or a polyaryl sulfide group each group containing from 2 to 6 aryl groups and R2 and R3 are each aryl groups having substituted thereon alkyl radicals having from 1 to 20 carbon atoms, phenyl radicals or alkaryl radicals, with an aryl iodide in the presence of an alkali metal base and a copper catalyst under an inert atmosphere at a temperature between about 100°C and about 225°C for a time sufficient to form the unsymmetrical, substituted di-tertiary amine.

Description

~3'.~ J~

PROCESS FOR PREPARIN~ ARYL Al\l NES

s BACKGROUND OF THE INVENTION
This invention relates to an improved chemical process for t} e preparation of unsymmetrical, substituted di-tertiary amines.
Various approaches have been utilized in the past for ~e production of unsymmetrical, substituted di-tertiary amines. For example, iodotoluenes have been reacted with diphenyl benzidines in the presence of potassium carbonate and a copper catalyst to form an unsymmetrical substituted di-tertiary amine. Such a process is disclosed, for example, in Example I of U.S. Patent 4,265,990 where N,N'-diphenyl[1,1'-biphenyl}-4,4'-diarnine s reacted with m-iodotoluene in the presence of a copper bronze catalyst, potassium carbonate and dirnethylsulfoxide. The diphenylbenzidine reactant can be made by oxidative coupling of diphenylamirle. However, low yields of 50 percent or less are obtained by oxidative coupling to foIm diphenylbenzidines. Moreover, exis~ng viable technology requires dichromate oxidation to effect the oxidative coupling. Disposal of chromium comlpounds poses a problem in view of restrictive ~overmnent regulations. In addition, oxidative coupling of diphenylamine is usually performed in dilute soluhons requiring large equipment investinents ~or 2s relatively low throughput. Further, oxidahve coupling of diphenylamine requires the use of large quantibes of acetic acid which must be recovered for the process to be economic~lly feasible. Also, iodololuene is relatiYely expensive and recovery of excess iodotoluene from the coupling reaction is not always possible because of biproduct foImation owing to alternative reaction pathways. In addition, there is a concern regarding possible safety hazards for iodotoluene cornpounds.
Unsymmetncal, substituted di-tertiary amine compounds may also be forrned by the reac~on of aLcyl diphenylarnines with di-iodoalyl compounds such as described in European Patent Application Serial Number 81300388.6 published May 5, 1982 under Publication Number 0034425. This reaction requires rigorous exclusion of air or oxygen during the coupling reaction between the di-iodoaryl and alkyl diphenylamine reactants. Impurities formed in this process are relatively similar in structure and polarity to the main product di-tertiary amine and hence are often difficult to remove in purification of the desired product. Di-iodorayl compounds may be obtained by reacting polyarylidene compounds with elemental iodine in the presence of an acidic solvent containing water, an oxidant, and an acid catalyst~ This process is disclosed, for example, in U. S. Patent 4,240,987. Elemental iodine is relatively expensive, but the process for recovery of elemental iodine from the potassium iodide (formed during the coupling reaction between the diiodoryl com-pound and the alkyl diphenylamine) is not practical or cost-effective.
Thus, there is a need for a process for conveniently and efficiently producing unsymmetrical, substituted di-tertiary amines which can be readily purified. In addition, there is a need for such a process employing precursors which are safe and readily available by high yield processes at low cost.
SUMMARY OF THE INVENTION
An aspect of the invention is as follows:
A process for preparing an unsymmetrical, substituted di-tertiary amine comprising reacting a di-secondary amine having -the general formula R2-HN-RlNH-R3 wherein Rl is a polyarylldene group, a polyarylether group or a polyaryl sulfide group each group containing from 2 to 6 aryl groups and R2 and R3 are each aryl groups having substituted thereon alkyl radicals having from 1 to 20 carbon atoms, phenyl radicals or alkaryl radicals, with an aryl iodide in the presence oF an alkali base presen-t as an excess in relation to said di-secondary ~ 3~

amine in a molar ratio of 2:1 and 8:1 and in the presence of a copper catalyst under an inert atmosphere at a temperature between about 100C and about 225C for a time sufficient to form said unsymmetrical, substituted di-tertiary amine.
S The di-secondary amines may be formed by reacting the dlalkali metal salt of a polyarylidene disulfonic acid, or the dialkali metal salt of a 1~, q~.

po]yarylether disu]fonic acid, or ~e dialkali metal salt of a polyarylsulfide disulfonic acid, with an ~kali me~ salt of an alkyl or alkaryl subs~ituted benzenearnine. The dialkali-metal salts of the polyarylidene disulfonic acid, the polyarylether disulfonic acid, or the polyarylsulfide disulfonic acid may be prepared by treating the appropriate disulfonic acid with an alkali metal halide dissolved in water. In turn, the polyarylidene disulfonic acid, the polyarylether disulfonic acid, or the polyarylsulfide disulfonic acid may be prepared by reacting the appropriate polyarylidene o compound, or the polyarylether, or the polyarylsulfide with concentrated sulfuric acid. The reaction product of the di-secondary arnine with a~ aryl iodide in the presence of an alkali rnetal hydroxide or alkali metal carbonate and a copper catalyst may be washçd with water to form an aqueous solution of soluble inorganic alkali metal iodides and hydroxides together with the solid reaction product. This aqueous solutiou when separated from the reaction product may be neutralized with sulfuric acid to form an alkali metal sulfate precipitate. The whole may be filtered to remove the alkali metal sulfate lea~ing the alkali metal iodide in solution.
20 The aqueous alkali metal iodide may subsequently be reacted with an arene dia~onium salt to form an a~l iodide, thus substantially recovering the iodine in a form useful for subsequent synthetic preparations.
As indicated above, the unsymmetrical, substituted di-secondary amines have the general forrnula R2-N~ NHR3, wherein Rl is a polyarylidene group, a polyarylether, or a polyarylsulfide, con[aining from 2 to 6 aryl groups, and R2 and R3 each are aryl groups havirlg substituted thereon alkyl radicals having from 1 to about 20 carbon atoms, phenyl radicals or alkaryl radicals. Alkyl radicals include preferably methyl but also include 30 the ethyl, propyl, n-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl and other alkyl radicals having up to about ~Q carbon atoms. Alkaryl radicals include, for example, methylphenyl and methylethylphenyl. Exarnples of these di-secondary amines are N,N'-bis-(3"-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine; N,N'-bis-(4"-n-butylphenyl)-~1,1'-biphenyl~-4,4'-diamine; 1~T,N'-bis-(3",4"-'~3'~

dimethylphenyl)-[1,1'-biphenyl]-4,4'-diamine; N,N'-bis-(2"-isopropylphenyl)-[1,1'-bipheny]]-4,4`-diamine; N,N'-bis-(4"-n-butylphenyl)-[1,1'-diphenylether]-4,4'-diarnine; N,N'-bis-(3"-methylphenyl)-[1,1'-diphenylsulfide]-4,4'-diamine and the like.
Any suitable aryl iodide may be employed. Typical aryl iodides include iodobenzene; r~-iodotoluene; p-iodotoluene; 3,4-dimethyliodobenzene; 4-iodobiphenyl; 4-me~hyl-4'-iodobiphenyl and the like.
o The condensation reaction to prepare the unsymmetrical di-tertiary amine is conducted in the presence of an alkali metal base and a copper ca[alyst. Any suitable alkali metal base may be employed. Typical alkali metal bases include potassium hydroxide, potassium carbonate, sodium hydroxide and the like. The reaction will not proceed at any reasonable rate without the presence of a base. Generally, copper catalysis, heretofore commonly used in the Ullman condensation reaction, may be employe~
Typiral copper catalysts include powdered copper me~al, cuprous oxide, cupric oxide, cuprous sulfate, cuprous iodide, cupric iodide, and the like ~o and mixtures thereof.
The condensation reaclion may be conducted either ~n the absence of a solvent, wi~ an inert saturated hydrocarbon solvent~ or with polar solvents such as sulfolane, dimethylsulfoxide or nitrobenzene. It is preferable to carry out the condensation reaction under an inert atmosphere at a temperature between about 100C and about 22SC for a period of time sufficient to substantially complete the reaction. Typical inert a~nospheres such as argon, ni~rogen, or carbon dioxide may be used.
The ratio of alkali metal base to di-secondary amine should be such that the base is present as an excess in relation to the di-secondary arnine.
This excess can range from about 2:1 up to about ~:1 in molar ratio. The preferred reaction temperature varies somewhat depending upon the alkali metal base utilize~ Satisfactory results may be achieYed with temperatures between about 100C and about 225~ with potassium hydroxide as the base. The preferred reaction temperature with potassium hydroxide as the ~3~

base and atl inert hydrocarbon as the solvent is between about 135C and about 165C in order to avoid substan~ial decomposi~ion of the reac~ion product while maintaining reasonable reaction rates. For temperatures below about 100C, the reac~ion does not proceed at a practical rate.
The process of the present invention may be carried out in the absence of a solvent when the di-secondary am~ne and the aryl iodide are miscible at temperatures above which they are in the molten state, or under conditions where one or the other of these two reactants acts as a solvent for the other.
Relatively pure products can be obtained with the present process when potassium hydroxide and an inert hydrocarbon solvent system is employed.
This is not always the case when an apro~c solvent or polar solvent is ,5 employe~ A fur~er advantage gained from ~e use of an inert high boiling hydrocarbon solvent lies in ~e fact that the intended reaction product can usually be purified from the same solvent. This eliminates difficult handling conditiorls and other tech~ological problems encountered when a dif~erent solvent or purifica~ion means must be employe~

2~ Any suitable inert aliphatic hydrocar~on having an initial boiling point above about 170C may be u~ ed. Typical inert aliphatic hydrocarbons 3nclude- dodecane, tetr~adecane, and the like. A par~cularly preferred solvent is Soltrol 170 hav~ng an initial boiling point of about 218C
2s containing a mixture of C13-C1s aliphatic hydrocarbons, or Sol~ol 130 having an intial boiling point of about 176C, both available firom Phillips Chemical Company.
The di-seco~dary amine may be prepared by reacting a dialkali metal salt of a polyarylidene di-sulfon~c acid, or a dialkali metal salt o~ a polyarylether disulfonic acid, or a dialkali rnetal salt of a polyaryl slllffde disulfouic acid with an alkali metal salt of an alkyl or alkaryl subs;tituted benzeneamine under an inert atmosphere. 7he re~ction is most efficiently carried out in ~he benzeneamine solven~ from which the alkali metal salt of the subs~ituted benzeneamine was derived.
Any suitable alkali metal sal~ of an ~lkyl or alka~l subs~ituted ~3 benzenearnine compound in which the alkyl or alkaryl groups contain up to 20 carbon atoms may be uti]ized in this reaction. Typical alkali metal salts of an alkyl or alkaryl substituted benzeneamine include sodium anilide, potassium anilide, sodium 3,4-dimethylanilide, potassium m-to]uidide, potassium p-toluidide, potassium-4-n-butylanilide, potassium-2-isopropylanilide, the potassium salt of 4-methyl-4'-aminobiphenyl, and the like.
Any suitable dialkali rnetal salt of a polyarylidene disulfonic acid, a o polyarylether disulfonic acid, or a polyarylsulfide disulfonic acid may be utilized in forrning the di-seconcary amine. Typical dialkali metal salls of the disulfonic acids include the dipotassio salt of 4,4'-biphenyldisulfonic acid, the dipotassio salt of 4,4"-terphenyldisulfonic acid, the dipo~ssio salt of 4,4'-[diphenylether3-disulfonic acid, the dipotassio salt of 4,4'-[diphenylsulfide3-disulfonic acid and the like. Generally, satisfactory results are obtained when the reaction between the dialkali metal salt of polyarylidene di-sulfonic acid, or the dialkali metal salt of a polyarylether disulfor~ic acid, or the di-alkali metal salt of a polyarylsulfide disulfonic 2~ acid and the alkali metal salt of an alkyl or alkaryl substituted benzene amine is conducted at a temperatures of be~ween about 120C and about 275C. A preferred temperature range between about 180C and 220C is used to optimi~e yield and reaction rate.
In general an excess of the primary arom~tic benzenearnine is employed as solvem and the alkali metal salt of this benzerleamine is prep~lred in situ. Upon addition of ~he dialkali metal salt of the polyarylidene disulfonic acid, and upon hea~ing the mixture to a temperature between about 18QC and 220C, the reaction proceeds to 30 completion withi~ from one to 48 hours. The reaction mixture may ~en be cooled to room temperature, treated with water and the organic phase may be separated from the aqueous phase. Any excess alkyl or alkaryl subs~ituted ben~eneamine may be recovered by distilla~on. The residue may then be dissolved in a suitable solvent such as dichloromethane, washed with dilute acid, and then with water. 1 he organic extract may be ~3~7l dried by any suitable means such as over anhydrous sodium sulfate and the so]vent removed under reduced pressure. The resu~ting solid is preferably stirred in methanol, filtered and dned.
The alkali metal salt of the alkyl or alkaryl substituted benzeneamine can be prepared by reacting a source of alkali me~l such as metallic sodium, metallic potassium, sodium amide or potassium amide and freshly distilled alkyl or alkaryl substiluted benzeneamine in the presence of a catalytic amount of copper at an elevated temperature of between 50C
lO and about 200C until all the alkali metal or alkali metal amide has dissolved. Generally the mole ratio of the alkyl or alkaryl substituted benzenearnine to the source of alkali metal is preferably between about 2:1 to about 10:1 for satisfactory results.
The dialkali metal salt of the polyarylidene disulfonic acid, or the polyarylether disulfonic acid, or ~e polyarylsulfide disulfonic acid, may be folmed by reacting the appropriate precursor with sulfuric acid at an elevated temperature of between about 50C and 200C and thereafter reacting with an alkali metal halide in an aqueous medium. Preferably the 20 disulforlic acid is mixed, while still hot, with a cold aqueous solution of ~e alkali metal h~lide. Subsequent cooling of the solu~on results in precipit~cion of the dialkali metal salt of the disulfonic acid which may subsequently be filtered and washed with a saturated alkali metal halide solution and subsequently washed with methanol to aid in drying of the alkali metal salt of the disulfonic acid. In gelleral after drying under vacuum the yields of dialkali metal s~lts of the disulfonic acids are in excess of 95 percen~
Any suitable polyarylidene compound, or polyarylether, or 30 polyarylsulfide may be employed to prepare the disulfonic acid. Typical compounds include biphenyl, terphenyl, p-quaterphenyl, diphenylether, 1,3-diphenoxybenzene, 1,4-diphenoxybenzene, diphenyl sulfide and the like.
3S Arly suitable alkali metal halide may be used to form the dialkali metal salt of the disulfonic acid of polyarylidene, the polyarylether, or the polyarylsulfide. Typical alkali metal salts inc]ude potassium chloride, sodium chloride, potassium bromide, potassium acetate, and the like.
Potassium chloride is preferred because of itS low cost, ready availability and because of the high reactivity of the subsequent potassio salts of the .
disulfonic acid.
Since the reaction product resulting ~rom condensation of the di-secondary arnine and the aryliodide in the presence of an alkali metal base and a copper catalyst contains relatively expensive dissolved iodide l0 compounds, it is preferred that the reaction mixture be neutralized with strong s~ lfuric acid to form an alkali metal sulfate precipitate which can be removed by filtration. The residual alkali metal iodides left in the resultant filtrate may then be concentrated and reacted with a diazonium salt of a substituted benzeneamine to reform the useful aryl iodide according to the procedure described, for exarnple, in Organic Synthesis, Collective Volume II, 351 [1943].
It is apparent that the process of this invention provides a safe inexpensive and efficient route for the high yield syn~esis of 20 unsymmetrical~ substituted di-tertiary amines as well as for the critica~
reactants subsequently utilized to ultimately forrn the unsymme~ical, substituted di-tertiary arnine.

DE~CRIPT10~ OF THE PREFE~MBODIME~TS
The invention will now be descnbed in detail wi~h respe~t to specific preferred embodiments thereof, it being understood that these exarnples are intended to be illustrative only. The invention is not intended to~ be limited to the materials, conditions, process parameters, etc. recited herein.
30 All parts and percentages are by weight unless otherwise indicated.
In the examples described below the analyses of the compounds were carried out as follows.
Combustion analyses were performed by Galbraith Laboratories, Knoxville, Tenn. Mass spectra were recorded in the standard electron ~ 3 impact mode on a Finni;,an 4500 quadruple mass spectrometer using theheated solid probe introduction technique. Proton magnetic resonance spectra [pmr] were obtained on a Bruker WP 80 Fourier transform 80 MHz nuclear magnetic resonance spectrometer. Chemical shifts are reported in parts per million [ppm] relative to tetramethylsilane as an internal standard.
SolYents are as indicated. Infrared spectra were recorded on a Beckmarm IR 4250 spectrometer calibrated against a polystyrene standard.

EXAMPLE I
A 2-liter round bottom flask equipped with an air condenser and a mechanical stirrer was charged with 462 grams of biphenyl (3 moles). To 15 this was added 1,470 grams (800 milliliters) of concentrated sulfunc acid (lSmoles). The reaction mixture was heated to 150C with stirring and held at this temperature for about 2 hour~s. The hot mixture was then poured, with s~irring, into a cold solution made up from about 2 liters of saturated potassium chloride and about 2 liters of water. A white precipitate ~rmed.
The rnixture was cooled in ice w~ter and then f~ltered. The resulting solid was washed wi~ about 1 to 2 liters of saturated potassium chloride solu~on.
The product was ~en dried under vacuum at about 100C to provide a 98 percent yield of about 1,150 grams of 4-4'-biphenyldisulfonic acid 25 dipotassio salt. NMR studies indic~te that no other isomers were fiormed.
The dipotassio salt is a colorless crys~lline material that is stable indefinitely.
PM~ (D20) - (q) 7.8-7.9 ppm (AA'-BB'~
Analysis calculated for C12HgO6S2K2: C, 36.91; H, 2.06; O, 24.58; S, 16.42; K, 20.03 Found: C, 36.92; H, 2.09; O, 24.40; S, 16.48; K, 2G.18 EXAMPLE Il ~3 - ~o-~ n a 250 milliliter, round bottom flask, equipped with an air condenser and a mechanical stirrer~ was placed 85 grams of diphenylether (0.5 moles).
To this was added 250 grams-(135 milliliters) of concentrated sulfuric acid (2.5 moles). The reaction mixture was heated to 130C with stirrin,, and held at this temperature for 2.5 hours. The hot mixture was then poured, with stirring into an ice cold solution made up of 1 liter of saturated aqueous sodium chloride and 1 liter of water. A white precipitate formed.
The mixture was cooled in ice water and then filtered. The solid was o washed with 1 liter of 50:50 saturated sodium chloride:water solution.
Optionally, the solid rnay be washed with 500 milliiiters of methanol in order to aid in the drying of the produc~ The produc~ was dried under vacuum at 100C to provide a yield of about 180 grams (96 percent~ of 4,4'-diphenylether disulfonic acid disodio sal~
PMR (D20) ppm 7.15-7.21 (4H), 7.82-7.88 (4H) AA'XX' spectrum Analysis calculated for C12HgS2O7Na2: C, 38.50; H, 2.15; S, 17.13; O, 29.92; Na, 12.29 Found C, 38.53; H, 2.09; S, 17.20; O 29.88; Na 12.30 A 3 neck, 1-liter, round bottom flask, equipped with a mechanical ~5 stirrer, condenser, a thermometer with temperature controller and a source of nitrogen was charged with about 600 millilite~s of freshly distilled meta-toluid~ne. To ~his was added 30.4 grams of sodium metal (1.3 moles) and a catalytic amount of copper (0.5 gram of copper metal). The mixture was ~en heated to about 110C for about 2 hours un~l all of the sodium metal was reacted. To this mixlure was added 117 grams of 4,4'-biphenyldisulforlic acid dipotassio salt (0.3 moles) prepared by another process described in ~ample 1- and about 134 grams oF anhydrous powdered potassiurn chloride ~1.8 moles). The reaction mixture was then 35 heated with stilTing, under a nitrogen atrnosphere, to about 200C and held

3~

at this temperature for about 24 hours. The reaction mixture was coo]ed to room temperature and poured into one liter of water The organic phase was separated from the aqueous phase and ~he excess me~a-toluidine was distilled off under vacuum to yield about 453 grams or about 90 percent of the recovered meta-toluidine. The residue was dissolved in about 300 milliliters of dichloromethane, washed with about 2 x 100 milliliters of about 10 percent HCI solution and then with 100 milliliters of water. The 10 percent HCI solution was employed to remove any excess meta-toluidine lO present after ~he distillation. The dichloromethane extract was dried over anhydrous sodium sulfate and the dichloromethane was ~ereafter removed under reduced pressure. The resulting solid was stirred in about 500 milliliters of methanol, filtered and dried to yield about 93 grams of a pale brown product N,N'-bis(3"-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine M.P.
156.5-158C (about 85 percent yield).
Analysis calculated for C20H24N2; C, 85.68, H, 6.64; N, 7.69 Fou~d: C, 85.71; H, 6.70; N, 7.70 ~o IR (crn-l); 3400 (-NH-) PMR (CDCl3) ppm; 2.32 (S, 6H), 5.69 (S, 2H), 6.75-6.77 (M, 2H), 6.90-6.92 (M, 4H), 7.10-7.20 (M, 6H), 7.46-1.49 (M, 4H), MS (m/z): 364 (M+) 2s EXAMPLE IV
Into a three neck, 500 millililer, round bottom flask, equipped with a mechanical stirrer, condenser, a thermometer with temperature controller and a source of nitrogen was placed ~00 milliliters of freshly distilled para-30 n-butylaniline. To this flask was added 11.S grarns of sodium metal (0.5 moles) and a ca~lytic amount of copper (~0.~ grarns of copper metal). The mixture was heated to 120C for 4 hours un~il all the sodium metal had reacted. To ~is mix~r~ was added 40 grams of 4.4'-biphenyldisulfonic acid dipotassio salt (0.1 moles) and 45 grams of anhydrous powdered potassium chloride (0.6 moles). The reaction mixure was then heated with ~'`3'~

stirring under a nitrogen atmosphere to 200C and held at this temperature for 24 hours. The reaction was cooled tO room temperature and poured into 300 milliliters of water. The organic phase was separated from ~e 5 aqueous phase and the excess para-n-butylaniline was distilled off under vacuum to yield 145 grarns or 85 percent of recovered para-n-butylar~iline.
The residue was dissolved in hot acetoni~ile. On cooling, a precipitate formed which was filtered and dried to yield 36 grarns of an off white product M.P. 172-174C of N,N'-bis(4"-n-butylphenyl)-~1,1'-biphenyl]-4,4'-diamine (80 percent yield).
MS (rn/z), 448 (M + ) Analysis calculated for C32H36N2: (~ 8~.67; H, 8.09; N, 6.25 Found: C, 85.54; H, 8.07; N, 6.39 EXAMPI,E V
Into a three neck, 250 milliliter, round bottom flask, equipped with a mechanical stirrer, condenser, a thermometer with temperature controller and a source of nitrogen was placed 100 milliliters of freshly dis~illed ortho-isopropylaniline. To this flask was added 6 grams of sodiu~ metal (0.26 moles) and a catalytic amount of copper. The mLxture was heated to 120C
for 4 hours until all the sodium metal has reacted. To this mLxture was 25 added 20 grams of 4,4'-biphenyldisulfonic acid dipotassio salt (O.Oj moles) and 23 grarns of anhydrous powdered potassium chloride (0.3 moles). The reaction mixure was then heated with s~i~ing under a nitrogen atmosphere to 200C and held at this tempera~ure for 24 hours. The reaction was 30 cooled to ~oom temperature and poured irto 150 milliliters of water. To this is added lOO milliliters of dichlorometh~ne. The organic phase was separated from the aqueous phase, dried over anhydrous sodium sulfate and the dichloromethane removed under reduced pressure. The excess ortho-isopropylaniline w s distilled off under vacuum to yield 70 milliliters 35 or 82 percent of recovered or~ho-isopropylaniline. The residue was L9~`~3~ dr~

recrystallized from acetonitri]e to yield 16.4 grams of off white product M.P.
153-155C of N,N'-bis(2"-isopropylphenyl)-[1,1`-biphenyll-4,4'diamine ( 78 percent yield).
s MS(m~z); 420 (M + ) Analysis calculated for C30H32N2: C, 85.67; H, 7.67; N, 6.66 Found: C, 85.71; H, 7.61; N, 6.68 o EXAMPLE Vl Into a three neck, 500 milliliter, round bottom flask, equipped with a mechanical stirrer, condenser, a thermometer with temper~ture controller and a source of nitrogen was placed 200 gr~s of freshly distilled 3,4-dimethylaniline. To this flask was added 11.5 grams of sodium metal (0.5 moles) and a c2talytic amount of copper (~0.2 grams of copper metal). The mixture was heated to 1~0C for 2 hours un~l all the sodium metal has reacted. To ~his mixture was added 40 grams of 4,4'-diphenyldisulfonic acid dipotassio salt (0.1 moles) and 45 grams of anhydrous powdered potassium chloride ~0.6 moles). The reaction mixure was then heated wi~
stirring under a nicrogen atrnosphere to 200C and held at this temperature for ~4 hours. The reaction was cooled to room tempera~ure and 300 milliliters of dichloromethane added to dissolve the solids. ~his was poured ~s into 300 milliliters of wa~er. The organic phase was separated from the aqueous phase, dried over anhydrous sodium sulfate and the dich~orornethane removed under reduced pressure. The excess 3,4-dirnethylaniline was distilled off under vacuum to yield 150 grams or 85 percent of recovered 3,4-dimetnylanilirle. The residue was recrystallized from acetonitrile to yield 32 grams of pale brown product M.P. 184-186, N,N'-bis(3",4"-dimethylphenyl)-Ll,l'-biphenyl~-4,4'diamine (about 80 percent yield).
3S MS (m/z); 392 ~M ~ ) Analysis calculated for C2gH2gN2: C, 85.67; H, 7.19; N, 7.14 Found: C, 85.75; H, 7.15; N, 7.10 EXAMPLE VII
Into a three neck, 500 milliliter, round bottom fl~.k, equipped with a mechanical stirrer, condenser, a thermometer with temperature controller and a source of nitrogen was placed 200 milliliters of freshly distilled para-n-butylaniline. To this flask w~s added 11.5 grams of sodium metal (0.5 moles) and a catalytic amount of copper (~0.2 grams of copper nletal). The mixture was heated to 120C for 4 hours until all the sodium metal has reacted. To this mixture was added 38 grams of 4,4'-diphenyletherdisulfonic acid disodio salt (0.1 moles) and 45 grams of S anhydrous powdered potassium chlonde (0.6 rnoles). The reaction mixure w~. ~en heated with stirring under a nitrogen atmosphere to 200C and held at this ternperature for 24 hours. The reaction was cooled to room temperature and poured into 300 milliliters of water. l~e organic phase was separated from the aqueous phase and the excess para-n-butylaniline was distilled off under Yacuum to yield 140 grams or 81 percent of recovered para-rl-butylaniline. The residue was recrystallized from acetonitrile to yield 36 grams of pale brown produc~ N,N'-bis(4"-n~
butylphenyl)-[1,1'-biphenylether]-4,4'-diamine (about 80 percent yield).

MS (m/z); 464 (M~) Analysis calculated for C32H36N~C): C, 82.72; H, 7.81, N, 6.03 Found: C, 82.63; H, 7.83; N, 6.14 EXA~IPL~E VIIl A 500 milliliter, round bottom, 3 neck flask fitted wi[h a mechanical stirrer, the~nometer with temperature controller and a source of r~trogen is charged with 36.4 grams of N,N'-bis(3"-methylphenyl)-~1,1'-biphenyl]-4,4'-diamine (0.1 mo]e~, 60.3 grams of iodoben2ene (0.3 mole), 44.8 grams of 3'~
- l5 - .
potassium hydro~;ide (0.8 mole~, 1.9 grarns of cuprous iodide (0.01 mole) and about 100 milliliters of a mixture of C13 Cl~ aliphatic hydrocarbons (Soltrol 170 available from Phillips Chemical Company~. The contents of the flask were heated to about 165C with stirring for a period of about 14 hours. Using a water aspirator, the excess iodobenzene was removed by vacuum distillation. The product was isolated by the addition of about 300 milliliters of Soltrol 170 followed by decantation to remove the inorganic solids. The filtrate was column chromatographed on Woelm neutral lO alumina using cyclohexane/benzene in a 3:2 ratio as the eluent. The resulting oil was recrystallized from n-octane to yie.'d about 42 grams of colorless crystals of N,N'-diphenyl-N,N'-bis(3"-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine having a melting point of about 167 to 169C
(about 80 percent yield).
MS (m/z): 516 (M+) Analysis calculated for C3~H32N2: C, 88.33; H, 6.24; N, S 42 Found: C, ~8.47; H, 6.21; N, 5.38 EXAMPLE I~
A 250 milliliter, 3 neck, ro~md bottorn flask, equipped with a mechanical stirrer, condenser and a source of nitrogen was charged with about 18.2 2~ . grams of N,N'-bis(3"-methylpheIlyl~-[1,1'-biphenyl]-4,4'-diamine (0.05 mole), 40.6 grams of iodobenzene (0.2 mole), 55.2 grams of powdered potassium carbon~te (0.4 mole) and about 50 milliliters of sulfolane (tetrahydrothiophene-1,1-~lioxide). The reaction mixture is heated to reflux at which time about 1.9 grams of cuprous iodide (0.01 mole) was adde~
The reaction mixture was heated for about 6 hours a~ gentle reflux. The flask was cooled and the contents poured into about 500 milliliters of water.
The organics were extracted with 2 x 200 milliliters of dichlorometha~e.
The extracts were dried over anhydrous sodium sulf~te and the 35 dichloromethane removed under reduced pressure to yield a brown oil.

The excess iodobenzene was recovered by steam distillation. The residue was dissolYed in dichloromethane, dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure to yield a beige so]id.
This solid was chromatographed using Woelm neutral alumina with cyclohexane/benzene in a 3:2 ratio as the eluent. The resulting oil was recrysiallized from n-ocLane to yeld about 21 grams of colorless crystals of N,N'-diphenyl-l!l,N'-bis(3"-methylphenyl)-11,1'-biphenyl~-4,4'-dia~nine having a melting point of about 167 to 169C (about 80 percent yield).

EXAMPLE X
A 500 milliliter, round bottom, ~ neck flask fitted with a mechanical stirrer, thermometer with temperature controller and a source of nitrogen -- was charged with 46.4 grams of N,N'-bis(4"-n-bu~lpheDyl)-El,1'-biphenylether]-4,4'-diamine (0.1 mole), 65.4 grams of meta-iodotcluene (0.3 moles), 44.8 grams of powdered potassium hydroxide (0.8 mole, 1.9 grams of cuprous iodide (0.01 mole) and about 100 milliliters of a mixcure of C13-C15 aliphatic hydrocarbons (Soltrol 170 available frorn Phillips Chemical 20 Company). The contents of the flask were heated to about 165C with stining fior a period of about 12 hours. The excess meta-iodotoluene was removed by vacuum distillation. The producl was isolated by the additon of about 300 milliliters of Soltrol 170 followed by decanta~ion to rernove the inorganic solids. The filtrate was colurnn chromatographed on Woelm neutral alumina using cyclohexane~toluene in a 3:2 ratio as the eluenL The resulting oil was recrystallized frorn n-octane to yield about 50 grams of colorless crystals of N,N'-bis(4"-n-butylphenyl)-N,N'-bis(3"-methylphenyl)-1,1'-biphenylether-4,4'-diarnine ~about 78 percent yield).

MS (rn/z): 644 (M + ) Analysis calculated for C4~H4gN~O: C, 85.67; H, 7.50; N, 4.35 Found: C, 85.56; H, 7.43; N~ 4.31 3~ .
~Ithough the invention has been described with reference to specific a~iL

pre~erred embodimenLs, it is not intended to be limited thereto, rather those skilled in the ar~ will recogni~e that variations and modifications may be made therein which are within the spirit of the invention and within the scope of the claims.

~0

Claims (16)

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

1. A process for preparing an unsymmetrical, substituted ditertiary amine comprising forming a di-secondary amine, having the general formula R2-HN-R1 NH-R3 wherein R1 is a polyarylidene group, a polyarylether group or a polyaryl sulfide group each group containing from 2 to 6 aryl groups and R2 and R3 are each aryl groups having substituted thereon alkyl radicals having from 1 to 20 carbon atoms, phenyl radicals or alkaryl radicals, by reacting a dialkali metal salt of a polyarlidene disulfonic acid, a dialkali metal salt of a polyarylether disulfonic acid or a dialkali metal salt of a polyaryl-sulfide disulfonic acid with an alkali metal salt of an alkyl or alkaryl substituted benzeneamine in which the alkyl groups contain from 1 to 20 carbon atoms in the presence of a solvent at a temperature between about 120°C and about 220°C under an inert atmosphere to form said di-secondary amine, reacting said di-secondary amine with an aryl iodide in the presence of an alkalibase present as an excess in relation to said di-secondary amine in a molar ratio of 2 1 and 8:1 and in the presence of a copper catalyst under an inert atmosphere at a temperature between about 100°C and about 225°C for a time sufficient to form said unsym-metrical, substituted di-tertiary amine.

2. A process according to claim 1 reacting said di-secondary amine with said aryliodide in the absence of a solvent.

3. A process according to claim 1 including reacting said di-secondary amine with said aryl iodide in the presence of a solvent.

4. A process according to claim 3 wherein said solvent is a high boiling hydrocarbon solvent.

5. A process according to claim 3 wherein said solvent is sulfolane (tetrahydrothiophene-1,1 dioxide).

6. A process according to claim 1 including mixing the reaction mixture resulting from reacting said dialkali metal salt of a polyarylidene disulfonic acid, a dialkali metal salt of a polyarylether disulfonic acid, or a dialkali metal salt of a polyarylsulfide disulfonic acid with said alkali metal salt of an alkyl or alkaryl substituted benzeneamine with water and a water immiscible solvent for the organic components of said reaction mixture to form separate layers of said organic components dissolved in said water immiscible solvent and said inorganic components dissolved in said water.

7. A process according to claim 6 including separating said organic components dissolved in said water immiscible solvent from said inorganic components dissolved in said water and removing said water immiscible solvent from said organic components by distillation.

8. A process according to claim 1 including forming said di-alkali metal salt of polyarylidene disulfonic acid by reacting a polyarylidene disulfonic acid with an alkali metal halide dissolved in water to form a precipitate of said dialkali metal salt of polyarylidene disulfonic acid.

9. A process according to claim 8 including forming said polyarylidene disulfonic acid by reacting a polyarl-idene compound with concentrated sulfuric acid at a temperature between about 50°C to about 200°C to form said polyarylidene disulfonic acid.

10. A process according to claim 9 wherein said polyarl-idene cornpound is biphenyl.

11. A process according to claim 9 including maintaining said polyarylidene disulfonic acid at an elevated temperature from said reacting of said polyarylidene compound with concentrated sulfuric acid until said polyarylidene disulfonic acid is reacted with said alkali metal halide dissolved in water to form a precip-itate of said dialkali metal salt of polyarylidene disulfonic acid.

12. A process according to claim 1 including forming said di-alkali metal salt of polyarylether disulfonic acid by reacting a polyarylether disulfonic acid with an alkali metal halide dissolved in water to form a precipitate of said dialkali metal salt of polyarylether disulfonic acid.

13. A process according to claim 12 including forming said polyarylether disulfonic acid by reacting a polyarl-ether compound with concentrated sulfuric acid at a temperature between about 50°C to about 200°C to form said polyarylether disulfonic acid.

14. A process according to claim 1 including forming said di-alkali metal salt of a polyarylsulfide disulfonic acid by reacting a polyarylsulfide disulfonic acid with an alkali metal halide dissolved in water to form a precipitate of said dialkali metal salt of polyarylsul-fide disulfonic acid.

15. A process according to claim 14 including forming said polyarylsulfide disulfonic acid by reacting a polyarylsulfide compound with concentrated sulfuric acid at a temperature between about 50°C to about 200°C
to form said polyarylsulfide disulfonic acid.

16. A process according to claim 1 including washing with water the reaction product from said reacting of said di-secondary amine with said aryl iodide in the presence of said alkali metal base and said copper catalyst to form an aqueous solution of soluble inorganic alkali metal compounds together with said reaction product, adding sulfonic acid to said solution to form an alkali metal sulphate precipitate, removing said alkali metal sulphate precipitate by filtration, and reacting he alkali metal iodide in the resulting filtrate with an arene diazonium salt to form an aryl iodide.