GB2147897A - Process for preparing di-tertiary aryl amines - Google Patents

Abstract

A process for preparing an unsymmetrical, substituted ditertiary 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 DEG C and about 225 DEG C for a time sufficient to form the unsymmetrical, substituted di-tertiary amine.

Description

SPECIFICATION Process for preparing aryl amines Background of the invention This invention relates to an improved chemical process for the preparation of unsymmetrical, substituted di-tertiary amines.

Various approaches have been utilized in the pastforthe 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'-diamine is reacted with m-iodotoluene in the presence of a copper bronze catalyst, potassium carbonate and dimethylsulfoxide. The diphenylbenzidine reactant can be made by oxidative coupling of diphenylamine. However, low yields of 50 percent or less are obtained by oxidative coupling to form diphenylbenzidines. Moreover, existing viable technology requires dichromate oxidation to effect the oxidative coupling.

Disposal of chromium compounds poses a problem in view of restrictive Government regulations. In addition, oxidative coupling of diphenylamine is usually performed in dilute solutions requiring large equipment investments for relatively low throughput. Further, oxidative coupling of diphenylamine requires the use of large quantities of acetic acid which must be recovered for the process to be economically feasible. Also, iodotoluene is relatively expensive and recovery of excess iodotoluene from the coupling reaction is not always possible because of biproductformation owing to alternative reaction pathways. In addition, there is a concern regarding possible safety hazards for iodotoluene compounds.

Unsymmetrical, substituted di-tertiary amine compounds may also be formed by the reaction of alkyl diphenylamines with di-iodoaryl compounds such as described in European Patent Application Serial Number 81300388.6, published May 5, 1982 under Publication Number 0034425. This reaction rigourous 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.

Diiodoaryl 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 diiodoaryl compound 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 In accordance with this invention, unsymmetrical, substituted di-tertiary amines are prepared by reacting a di-secondary amine having the general formula R2-NH-R1 -NH-P3, wherein R1 is a polyarylidene group, a polyarylether, or a polyaryl sulfide, in each case containing from 2 to 6 aryl groups, and R2 and R3 each are aryl groups having substituted thereon alkyl radicals having from 1 to about 20 carbon atoms, phenyl radicals or alkaryl radicals, with an aryl iodide in the presence of an alkali metal base and copper catalyst under an inert atmosphere at a temperature between about 100or and about 2250C for a time sufficient to form the unsymmetrical, substituted di-tertiary amine.

The di-secondary amines may be formed by reacting the dialkali metal salt of a polyarylidene disulfonic acid, or the dialkali metal salt of a polyarylether disulfonic acid, or the dialkali metal salt of a polyarylsulfide disulfonic acid, with an alkali metal salt of an alkyl or alkaryl substituted benzeneamine. The dialkali metal salts of the polyarylidene disulfonic acid, the polyarylether disulfonic acid, or the polyarysulfide 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 compound, or the polyarylether, or the polyarylsulfide with concentrated sulfuric acid.The reaction product of the di-secondary amine with an aryl iodide in the presence of an alkali metal hydroxide or alkali metal carbonate and a copper catalyst may be washed with water to form an aqueous solution of soluble inorganic alkali metal iodides and hydroxides together with the solid reaction product. This aqueous solution 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 leaving the alkali metal iodide in solution. The aqueous alkali metal iodide may subsequently be reacted with an arene diazonium salt for form an aryl 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 formula R2-NH-Rn -NHR3, wherein R1 is a polyarylidene group, a polyarylether, or a polyarylsulfide, containing from 2 to 6 aryl groups, and R2 and P3 each are aryl groups having 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 the ethyl, propyl, n-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl and other alkyl radicals having up to about 20 carbon atoms. Alkaryl radicals include, for example, methylphenyl and methylethylphenyl.Examples 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; N,N'-bis(3",4" dimethylphenyl)-11,1'-biphenyl]4-4'-diamine; N,N'-bis-(2"-isopropylphenyl)-[1,1'-biphenyl]-4,4'-diamine; N,N'-bis-(4"-n-butylphenyl-[1,1'-diphenylether]-4,4'-diamine; 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; m-iodotoluene; p-iodotoluene; 3,4-dimethyliodobenzene; 4-iodobiphenyl; 4-methyl-4'-iodobiphenyl and the like.

The condensation reaction to prepare the unsymmetrical di-tertiary amine is conducted in the presence of an alkali metal base and a copper catalyst. 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 employed. Typical copper catalyst include powered copper metal, cuprous oxide, cupric oxide, cuprous sulfate, cuprous iodide, cupric iodide, and the like and mixtures thereof.

The condensation reaction may be conducted either in the absence of a solvent, with an inert saturated hydrocarbon solvent, or with polar solvents such assulfolane, dimethylsulfoxide or nitrobenzene. It is preferable to carry out the condensation reaction under an inert atmosphere at a temperature between about 1005C and about 225"C for a period of time sufficient to substantially complete the reaction. Typical inert atmospheres such as argon, nitrogen, 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 amine. This excess can range from about 2:1 up to about 8:1 in molar ratio. The preferred reaction temperature varies somewhat depending upon the alkali metal base utilized. Satisfactory results may be achieved with temperatures between about 100"C and about 225"C with potassium hydroxide as the base. The preferred reaction temperature with potassium hydroxide as the base and an inert hydrocarbon as the solvent is between about 135"C and about 1 65"C in order to avoid substantial decomposition of the reaction product while maintaining reasonable reaction rates.For temperatures below about 100"C, the reaction 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 amine 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 act 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 aprotic solvent or polar solvent is employed. A further advantage gained from the use of an inert high boiling hydrocarbon solvent lies in the fact that the intended reaction product can usually be purified from the same solvent. This eliminates difficult handling conditions and other technological problems encountered when a different solvent or purification means must be employed.

Any suitable inert aliphatic hydrocarbon having an initial boiling point above about 170"C may be utilized.

Typical inert aliphatic hydrocarbons include dodecane, tetradecane, and the like. A particularly preferred solvent is Soltrol 170 having an initial boiling point of about 218"C containing a mixture of C13-C15 aliphatic hydrocarbons, or Soltrol 130 having an initial boiling point of about 176"C, both available from Phillips Chemical Company.

The di-secondary amine may be preferred by reacting a dialkali metal salt of a polyarylidene dilsulfonic acid, or 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 under an inert atmosphere. The reaction is most efficiently carried out in the benzeneamine solvent from which the alkali metal salt of the substituted benzeneamine was derived.

Any suitable alkali metal salt of an alkyl or alkaryl substituted benzeneamine compound in which the alkyl or alkaryl groups contain up to 20 carbon atoms may be utilized in this reaction. Typical alkali metal salts of an alkyl or alkaryl substituted benzeneamine include sodium anilide, sodium 3,4-dimethylanilide, potassium m-toluidide, potassium p-toluidide, potassium-4-n-butylamilide, potassium-2-isopropylanilide, the potassium salt of 4-methyl-4'-aminobiphenyl, and the like.

Any suitable dialkali metal salt of a polyarylidene disulfonic acid, a polyartyether disulfonic acid, or a polyarylsulfide disulfonic acid may be utilized in forming the di-secondary amine. Typical dialkali metal salts of the disulfonic acids include the dipotassio salt of 4,4'-biphenyldisulfonic acid, the dipotassio salt of 4,4"-terphenyldisulfonic acid, the dipotassio salt of 4,4'-[diphenylether]-disulfonic acid, the dipotassio salt of 4,4'-[diphenylsulfide]-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 disulfonic acid, or the di-alkali metal salt of a polyarylsulfide disulfonic acid and the alkali metal salt of an alkyl or alkaryl substituted benzene amine is conducted at a temperatures of between about 120"C and about 275 C. A preferred temperature range between about 180"C and 220"C is used to optimize yield and reaction rate.

In general an excess of the primary aromatic benzeneamine is employed as solvent and the alkali metal salt of this benzeneamine is prepared in situ. Upon addition of the dialkali metal salt of the polyarylidene disulfonic acid, and upon heating the mixture to a temperature between about 180 C and 220"C, the reaction proceeds to completion within from one to 48 hours. The reaction mixture may then be cooled to room temperature, treated with water and the organic phase may be separated from the aqueous phase. Any excess alkyl or alkaryl substituted benzeneamine may be recovered by distillation. The residue may then be dissolved in a suitable solvent such as dichloromethane, washed with dilute acid, and then with water.The organic extract may be dried by any suitable means such as ober anhydrous sodium sulfate and the solvent removed under reduced pressure. The resulting solid is preferably stirred in methanol, filtered and dried.

The alkali metal salt of the alkyl of alkaryl substituted benzeneamine can be prepared by reacting a source of alkali metal such as metallic sodium, metallic potassium, sodium amide or potassium amide and freshly distilled alkyl or alkaryl substituted benzeneamine in the presence of a catalytic amount of copper at an elevated temperature of between 50"C and about 200"C until all the alkali metal of alkali metal amide has dissolved. Generally the mole ratio of the alkyl or alkaryl substituted benzeneamine 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 the polyarylsulfide disulfonic acid, may be formed by reacting the appropriate precursor with sulfuric acid at an elevated temperature of between about 50"C and 200"C and thereafter reacting with an alkali metal halide in an aqueous medium. Preferably the disulfonic acid is mixed, while still hot, with a cold aqueous solution of the alkali metal halide. Subsequent cooling of the solution results in precipitation 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 general after drying under vacuum the yields of dialkali metal salts of the salts of the disulfonic acids are in excess of 95 percent.

Any suitable polyarylidene compound, or polyarylether, or polyarylsulfide may be employed to prepare the disulfonic acid. Typical compounds include biphenyl, p-quaterphenyl, diphenylether, 1,3 diphenoxybenzene, 1 ,4-diphenoxybenzene, diphenyl sulfide and the like.

Any suitable alkali metal halide may be used to form the dialkali metal salt of the disulfonic acid of polyarylidene, the polyarylether, orthe polyarylsulfide. Typical alkali metal salts include potassium chloride, sodium chloride, 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 from condensation of the di-secondary amine and the aryliodide in the presence of an alkali metal base and a copper catalyst contains relatively expensive dissolved iodide compounds, it is preferred that the reaction mixture be neutralized with strong sulfuric 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 example in Organic Synthesis, Collective Volume 11,351 [1943].

It is apparent that the process of this invention provides a safe, inexpensive and efficient route for the high yield synthesis of unsymmetrical, substituted di-tertiary amines as well as for the critical reactants subseqently utilized to ultimately form the unsymmetrical, substituted di-tertiary amine.

Description of the preferred embodiments The invention will now be described in detail with respect to specific preferred embodiments thereof, it being understood that these examples are intended to be illustrative only. The invention is not intended to be limited to the materials, conditions, process parameters, etc. recited herein. 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 impact mode on a Finnigan 4500 quadruple mass spectrometer using the heated 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. Solvents are as indicated. Infrared spectra were recorded on a Beckmann IR 4250 spectrometer calibrated against a polystyrene standard.

Example I A 2-litre round bottom flask equipped with an air condenser and a mechanical stirrer was charged with 462 grams of biphenyl (3 moles). To this was added 1,470 (800 milliliters) of concentrated sulfuric acid (15 moles). The reaction mixture was heated to 1 500C with stirring and held at this temperature for about 2 hours. The hot mixture was then poured, with stirring, into a cold solution made up from about 2 liters of saturated potassium chloride and about 2 liters of water. A white precipitate formed. The mixture was cooled in ice water and then filtered. The resulting solid was washed with about 1 to 2 liters of saturated potassium chloride solution.The product was then dried under vacuum at about 100 C to provide a 98 percent yield of about 1,150 grams of 4-4'-biphenyldisulfonic acid dipotassio salt. NMR studies indicate that no other isomers were formed. The dipotassio salt is a colorless crystalline material that is stable indefinitely.

PMR (D2O) - (q) 7.8-7.9 ppm (AA'-BB') Analysis calculated for C12H8O6S2K2: C, 36.91; H, 2.06; 0, 24.58; S, 16.42; K. 20.03 Found: C, 36.92; H, 2.09; 0,24.40; S, 16.48 K, 20.18 Example II In 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 1 30"C with stirring 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 washed with 1 liter of 50:50 saturated sodium chloride: water solution.

Optionally, the solid may be washed with 500 milliliters of methanol in order to aid in the drying of the product. The product was dried under vacuum at 100 Cto provide a yield of about 180 grams (96 percent) of 4,4'-diphenylether disulfonic acid disodio salt.

PMR (D2O) ppm 7.15-7.21 (4H), 7.82-7.88 (4H) AA'XX' spectrum Analysis calculated for C12HsS207Na2: C, 38.50; H, 2.15; S, 17.13; 0,29.92; Na, 12.29 Found C, 38.53; H, 2.09 S,17.20; 0,29.88; Na 12.30 Example 111 A 3 neck, 1-litre, round bottom flask, equipped with a mechanical stirrer, condenser, a thermometer with temperature controller and a source of nitrogen was charged with about 600 milliliters of freshly distilled metatoluidine. To this 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 then heated to about 1 10"C for about 2 hours until all of the sodium metal was reacted.To this mixture was added 117 grams of 4,4'-biphenyldisulfonic acid dipotassio salt (0.3 moles) prepared by another process described in Example I and about 134 grams of anhydrous powdered potassium chloride (1.8 moles). The reaction mixture was then heated with stirring, under a nitrogen atmosphere, to about 200 C and held at this temperature for about 24 hours. The reaction mixture was cooled to room temperature and poured into one liter of water. The organic phase was separated from the aqueous phase and the excess meta-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 CHI solution and then 100 milliliters of water. The 10 percent HCI solution was employed to remove any excess meta-toluidine present after the distillation. The dichloromethane extract was dried over anhydrous soldium sulfate and the dichloromethane was thereafter 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. 156-5-158"C (about 85 percent yield).

Analysis calculated for C20H24N2; C, 85.68, H, 6.64; N, 7.69 Found: C, 85.71; H, 6.70; N, 7.70 IR (cm-'); 3400 (-NH-) PMR (CDCI3) 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), 7.46-7.49 (M, 4H), MS (mix): 364 (MT) Example IV Into a three neck, 500 milliliter, round bottom flask, 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-butylaniiine. To this flask was added 11.5 grams of sodium metal (0.5 moles) and a catalytic amount of copper (-0.2 grams of copper metal).The mixture was heated to 1 20"C for 4 hours until all the sodium metal had reacted. To this mixture 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 mixture was then heated with stirring under a nitrogen atmosphere to 200"C 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 the aqueous phase and the excess para-n-butylaniline was distilled off under vacuum to yield 145 grams or 85 percent of recovered para-n-butylaniline. The residue was dissolved in hot acetonitrile. On cooling, a precipitate formed which was filtered and dried to yield 36 grams of an off white product M.P. 172-174"C of N,N'-bis(4"-butylphenyl)-[1,1 '-biphenyl]-4,4'-diamine (80 percent yield).

MS (miz),448 (Mt) Analysis calculated for C32H36N2: C 85.67; H, 8.09; N, 6.25 Found: C, 85.54; H, 8.07; N, 6.39 Example 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 distilled orthoisopropylaniline. To this flask was added 6 grams of sodium metal (0.26 moles) and a catalytic amount of copper. The mixture was heated to 1 20"C for 4 hours until all the sodium metal has reacted. To this mixture was added 20 grams of 4,4'-biphenyldisulfonic acid dipotassio salt (0.05 moles) and 23 grams of anhydrous powdered potassium chloride (0.3 moles).The reaction mixture was then heated with stirring under a nitrogen atmosphere to 2000C and held at this temperature for 24 hours. The reaction was cooled to room temperature and poured into 150 milliliters of water. To this is added 100 milliliters of dichloromethane. The organic phase was separated from the aqueous phase, dried over anhydrous sodium sulfate and the dichloromethane removed under reduced pressure. The excess ortholisopropylaniline was distilled off under vacuum to yield 70 milliliters or 82 percent of recovered ortho-isopropylaniline. The residue was recrystallized from acetonitrile to yield 16.4 grams of off white product M.P. 153-155"C of N,N'-bis(2"-isopropylphenyl)-[1,1 '-biphenyl]-4,4'diamine (78 percent yield).

MS (my); 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 Example Vl Into a three neck, 500 milliliter, round bottom flask, equipped with a mechanical stirrer, condenser, a thermometer with temperature controller and a source of nitrogen was placed 200 grams of freshly distilled 3,4-dimethylaniline. To this flask was added 11.5 grams of sodium metal (0.5 moles) and a catalytic amount of copper (0.2 grams of copper metal). The mixture was heated to 120'C for 2 hours until all the sodium metal has reacted. To this 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 mixture was then heated with stirring under a nitrogen atmosphere to 200"C and held at this temperature for 24 hours. The reaction was cooled to room temperatre and 300 milliliters of dichloromethane added to dissolve the solids.

This was poured into 300 milliliters of water. The organic phase was separated from the aqueous phase, dried over anhydrous sodium sulfate and the dichloromethane removed under reduced pressure. The excess 3,4-dimethylaniline was distilled off under vacuum to yield 150 grams or 85 percent of recovered 3,4-dimethylaniline. The residue was recrystallized from acetonitrile to yield 32 grams of pale brown product M.P. 184-186", N,N'-bis(3",4"-dimethylphenyl)-[1 ,1 '-biphenyl]-4,4'diamine (about 80 percent yield).

MS (m/z); 392 (M+) Analysis calculated for C28H28N2: C, 85.67; H, 7.19; N, 7.14 Found: C,85;75; H, 7.15; N, 7.10 Example Vll Into a three neck, 500 milliliter, round bottom flask, 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 was added 11.5 grams of sodium metal (0.5 moles) and a catalytic amount of copper (-0.2 grams of copper metal). The mixture was heated to 1 20"C 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 anhydrous powdered potassium chloride (0.6 moles).The reaction mixture was then heated with stirring under a nitrogen atmosphere to 200"C 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 the aqueous phase and the excess para-n-butylaniline was distilled off under vacuum to yield 140 grams or 81 percent of recovered para-n-butylaniline. The residue was recrystallized from acetonitrile to yield 36 grams of pale brown product N,N'-bis(4"-n-butylphenyl-[1,1 '-biphenylether]- 4,4'-diamine (about 80 percent yield).

MS (m/z); 464 (M .+) Analysis calculated for C32H36N2O: C, 82.72; H, 7.81; N, 6.03 Found: C, 82.63; H, 7.83; N, 6.14 Example VIII A 500 milliliter, round bottom, 3 neck flask fitted with a mechanical stirrer, thermometer with temperature controller and a source of nitrogen is charged with 36.4 grams of N,N'-bis(3"-methylphenyl)-[1,1 '-biphenyl]- 4,4'-diamine (0.1 mole), 60.3 grams of iodobenzene (0.3 mole), 44.8 grams of potassium hydroxide (0.8 mole), 1.9 grams of cuprous iodide(0.01 mole) and about 100 milliliters of a mixture of Ca3-Ca5 aliphatic hydrocarbons (soltrol 170 available from Phillips Chemical Company).The contents of the flask were heated to about 165"C 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 alumina using cyclohexane/benzene in a 3:2 ratio as the eluent. The resulting oil was recrystallized from n-octane to yield about 42 grams of colorless crystals of N,N'-diphenyl-N,N '-bis(3" methylphenyl)-[1,1 '-biphenyl]-4A'-diamine having a melting point of about 167 to 169C (about 80 percent yield).

MS (m/z): 516 (M .+) Analysis calculated for C38H32N2: C, 88.33; H, 6.24; N, 5.42 Found: C, 88.47; H, 6.21; N, 5.38 Example IX A 250 milliliter, 3 neck, round bottom flask, equipped with a mechanical stirrer, condenser and a source of nitrogen was charged with about 18.2 grams of N,N'-bis(3"-methylphenyl)-[1,1 '-biphenyl]-4,4'-diamine (0.05 mole), 40.6 grams of iodobenzene (0.2 mole), 55.2 grams of powedered potassium carbonate (0.4 mole) and about 50 milliliters of sulfolane (tetrahydrothiophene-1 ,1 -dioxide). The reaction mixture is heated to reflux at which time about 1.9 grams of cuprous iodide (0.01 mole) was added. The reaction mixture was heated for about 6 hours at 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 dichloromethane. The extracts were dried over anhydrous sodium sulfate and the dichloromethane removed under reduced pressure to yield a brown oil.

The excess iodobenzene was recovered by steam distillation. The residue was dissolved in dichloromethane, dried over anhydrous soldium sulfate and the solvent was removed under reduced pressure to yield a beige solid. This solid was chromotographed using Woelm neutral alumina with cyclohexane/benzene in a 3:2 ratio as the eluent. The resulting oil was recrystallized from n-octane to yeld about 21 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 169"C )about 80 percent yield).

Example A 500 milliliter, round bottom, 3 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-butylphenyl)-[1,1 '- biphenylether]-4,4'-diame (0.1 mole), 65.4 grams of meta-iodotoluene (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 mixture of C13-C15 aliphatic hydrocarbons (Soltrol 170 available from Phillips Chemical Company). The contents of the flask were heated to about 165"C with stirring for a period of about 12 hours. The excess meta-iodotoluene 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 alumina using cyclohexane/toluene in a 3:2 ratio as the eluent. The resulting oil was recrystallized fron n-octane to yield about 50 grams of colorless crystals of N,N'-bis(4"-n butylphenyl)-N,N '-bis(3"-methyl phenyl)-1 ,1 '-biphenylether-4,4'-diamine (about 78 percent yield).

MS (my): 644 (M r) Analysis calculated for C46H48N2O: C, 84.67; H, 7.50; N, 4.35 Found: C, 85.56; H, 7.43; N, 4.31

Claims (17)

1. A process for preparing an unsymmetrical, substituted di-tertiary amine comprising reacting a di-secondary amine having the general formula R2-HN-Ra -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 P3 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 said unsymmetrical, substituted di-tertiary amine.

2. A process according to Claim 1 reacting said di-secondary amine with said aryl iodide 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 forming said di-secondary amine by reacting a 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 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.

7. A process according to Claim 6 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 imiscible solvent for the organic components of said reaction mixture to form separate layers of said organic components dissolved in said water imiscible solvent and said inorganic components dissolved in said water.

8. A process according to Claim 7 including separating said organic components dissolved in said water miscible solvent from said inorganic components dissolved in said water and removing said water imiscible solventfrom said organic components by distillation.

9. A process according to Claim 6 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.

10. A process according to Claim 9 including forming said polyarylidene disulfonic acid by reacting a polyarylidene compound with concentrated sulfuric acid at a temperature between about 50"C to about 200"C to form said polyarylidene disulfonic acid.

11. A process according to Claim 10 wherein said polyarylidene compound is biphenyl.

12. A process according to Claim 10 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 precipitate of said dialkali metal salt of polyarylidene disulfonic acid.

13. A process according to Claim 6 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.

14. A process according to Claim 13 including forming said polyarylether disulfonic acid by reacting a polyarylether compound with concentrated sulfuric acid at a temperature between about 50"C to about 200"C to form said polyarylether disulfonic acids.

15. A process according to Claim 6 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 di-alkali metal salt of polyarylsulfide disulfonic acid.

16. A process according to Claim 15 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.

17. 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 sulfuric acid to said solution to form an alkali metal sulphate precipitate, removing said alkali metal sulphate precipitate by filtration, and reacting the alkali metal iodide in the resulting filtrate with an arene diazonium salt to form an aryl iodide.