J. MATER. CHEM., 1994, 4( lo), 1527-1532 Novel Aromatic Poly(ether ketone)s Part 3.t-Synthesis of Diamine Precursors with 4-8 Benzene Rings Linked by Ether, Ketone and Sulfone Groups Anthony J. Lawson,as Peter L. Pauson: David C. Sherrington,”* Stella M. Youngbs and (in part) Niall O’Brienbn a Department of Pure and Applied Chemistry, University of Strathclyde, 295, Cathedral Street, Glasgo w, UK G1 1XL ICI Wilton Materials Research Centre, Middlesbrough, Cleveland, UK TS6 8JE Fourteen new diamines have been synthesized for use in the work described in parts 1 and 2. A combination of Friedel-Crafts acylation of arenes with nitro- and fluoro-benzoyl chlorides and benzene dicarbonyl chlorides, Ullmann synthesis of aryl ethers from phenols and fluoroarenes and reduction of nitro to amino groups by transfer hydrogenation has been employed.In the synthesis of poly(ether keto imide)s aimed at producing materials with the optimum combination of the properties of polyimides and poly(ether ketone)s attention has focussed mainly on precursor diamines with up to five benzene rings connected by ether and ketone functions. In the main the first linkage to the terminal aromatic amine has been an ether one.’ Recently Eastmond et aL2 have also been exploring the effect of introducing aromatic ether and ketone linkages in the acid dianhydride component. In the present paper we describe the synthesis of 14 new diamines with 4-8 benzene rings linked by ether, ketone and sulfone groups where the first linkage to the terminal aromatic amine is generally ketonic.These molecules were required to obtain the polyamides and polyimides which are the subject of the two preceding paper^.^ Discussion Most of these diamines were obtained by reduction of the corresponding dinitro compounds which, in turn, were the products of Friedel-Crafts reactions between diphenyl ether and its derivatives or biphenyl with 3-or 4-nitrobenzoyl chloride. Use of 2-2.2mol of the latter led directly to sym- metrical dinitro compounds, whereas equimolar quantities of substituted benzoyl chlorides and aryl ethers led cleanly to the monoacylated products, allowing a different aroyl chloride to be used in the second acylation step to obtain unsymmetri- cal dinitro compounds. The aromatic ethers containing four to six rings, required for the 6-8 ring diamines, were them- selves generated by two routes: either Friedel-Crafts acylation of simpler aryl ethers by terephthaloyl or isophthaloyl chlor- ides or Ullmann ether synthesis from phenols and fluoroarenes activated by carbonyl or sulfonyl groups.The specific compounds synthesized are shown in Tables 1-4 and one example of each procedure is given in full in the Experimental section. To facilitate relatively large-scale preparation and avoid the more toxic or highly flammable materials, dichloroethane was the preferred solvent for acyl- ation, rather than carbon disulfide which had commonly been employed in the earlier literature. Transfer hydrogenation employing cyclohexene as hydrogen source proved consist- t Part 2: J.Mater. Chem., 1994, 4, 1521. J, Present address: Vinamul Ltd., Mill Lane, Carshalton, Surrey SM5. $Present address: I.C.I. plc, Fluon R & T, York House, Hillhouse International, Thornton, Cleveleys, Lancashire FY5 4QD. 5[ Present address: Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL. ently convenient for nitro-group reduction; yields generally in the 50-70% region for this step were regarded as satisfactory in view of the low solubilities of both the nitro prccursors and the final amino compounds and the resultant handling problems. The only amines not prepared via the corresponding nitro-compounds were the five-ring diamine (7A), the six-ring diamine (8A) and the eight-ring diamine ( 16A), all synthesized, albeit in varying yields, by routes employing the IJllmann ether synthesis in the final step (see Table 4).Table 3 gives preparative details for and properties of the nitro compounds. The yields attained in refluxing 1,2-dichloroethane are seen to be appreciably better than by the much slower reaction at room temperature in dichloro-methane. Such conditions failed to yield the required ciisubsti- tution product (compound 4N) when applied to biphcnyl and 4-nitrobenzoyl chloride; assuming that the initial monosubsti- tuted product was deactivated by forming too strong a complex with aluminium chloride, we replaced the latter by iron(II1) chloride and obtained the required product in modest yield.Experimental The synthetic results are summarised in Tables 2-4; the following details are representative of the principal methods employed and significant variations are noted in the ‘tables. Literature methods were followed for the preparation of 1,4-diphenoxybenzene (hydroquinone diphenyl ether)4 and for compound 19(b).5 ‘H NMR spectroscopic data follow the preparative methods. Friedel-Crafts Acylations Compound 5N 1,4-Diphenoxybenzene (5.24 g, 0.02 mol) and 4-nitro benzoyl chloride (7.42 g, 0.04 mol) were dissolved in 1,2-dichloroethane ( 100 ml) and aluminium chloride (5.32 g, 0.04 mol) wa.; added. The mixture was refluxed for 2 h, then cooled and poured onto ice acidified with hydrochloric acid.The organic layer was separated, washed with 2 moll-’ sodium hydroxide and water, dried (MgS04) and evaporated. The residue wa.i recrys- tallised from dimethyl formamide-water to give the cream- coloured crystalline dinitro compound (5N) (10 g) (see Table 3). In some acylations product precipitated before separation of the layers; such precipitates were collected by filtration, well washed with water, dried and later combined with any product recovered from the organic layer. Analysis showed J. MATER. CHEM., 1994, VOL. 4 no. structure 1A: X=H 1N: X=O 2A: X=H 2N: X=O 3A: X=H 3N: X=O 4A: X=H 4N: X=O 5A: X=H 5N: X=O NX2 6A: X=H 6N: X=O 7A %A 9A: X=H 9N: X=O Table 1 List of diamines and precursors synthesized 0 0 0mNX2 0 0 NX2 0aoqp" 0 0 0 0 Nx2& \ 0&0hNX2 10A: X=H 10N: X=O 11A: X=H 11N: X=O 0 0 12A: X=H 12N: X=O J. MATER.CHEM., 1994, VOL. 4 1529 Table 1 (continued) no. structure 13A: X=H 13N: X=O 14A: X=H 14N: X=O 15A: X=H 15N: X=O 16A: X=H 16N: X=O 17(a)R= 3 -NO, 17(b)R=4 -NO, 17(~)R=3-F 17(d)R=4 -F 18A: X=H 18N: X=O 19(~):3,3’-F 19(b): 4,4’-F 20 21 Nx2* \ 0J0hNX2 NX2-o-”qp”qp”qp”~\ \ \ NXz 0 0 0 0 RhoD F&NX2 0 0 F-~o&-F F 0 0 F 0 0 that the less soluble products obtained in this way were pure enought for further work without recrystallisation. Some sparingly soluble nitro compounds, unsuitable for conven- tional recrystallisation, were placed in a Soxhlet apparatus and crystallised by prolonged extraction (1-3 days). For monoacylations of substrates liable to undergo disubsti- tution it was considered preferable to form the Perrier complex from a solution of the aroyl chloride and aluminium chloride and to filter this solution before adding the reactive arene (1:1:1 molar ratio).All aryl ketones synthesized had IR carbonyl peaks near 1650 cm-l; nitro groups gave rise to bands at 1510-1530 and at 1350 cm-l. Nitro Reduction by Pd-catalysed Transfer Hydrogenation Compound 1A Palladium on charcoal (1.06 g, 10%) was added to the dinitro compound (1N) (25 g, 0.053 mol) in DMF (250 ml) and cyclohexene (75 ml). This mixture was refluxed, employing a Dean and Stark trap, until no more water was seen tci collect in this trap and TLC indicated the complete disappearance of compound (1N) (typically 3 h).After removing the catalyst from the cooled mixture by filtration, a mixture of cyclo hexadi- ene and cyclohexene was distilled off and the residual DMF solution was diluted with water to precipitate a pale yellow solid. Recrystallisation from toluene gave the diamine (1A) (12.6 g) (see Table 2). Several of the higher-molecular-weight diamines N ere too insoluble to undergo satisfactory recrystallisation, but the products precipitating from the reaction mixture were found to be analytically pure or nearly so. Ullmann Ether Synthesis Diamine 7A To 4-amino-4-fluorobenzophenone ( 18A) (21.5 g, (1.1 mol) in N-methylpyrrolidin-2-one (200 ml), resorcinol (5.28 g, J.MATER. CHEM., 1994, VOL. 4 Table 2 Synthesis and analyses of amines (for structures see Table 1) found (%) calcd. (YO) molecular mlz amine precursor mp/"C yield (YO) formula C H N C H N found (theor.) 1A 1N 174-76" 76.5 4.7 7.0 76.5 4.9 6.9 -2A 2N 186-87 76.5 4.8 6.9 76.5 4.9 6.9 -3A 3N 144-46b 60 76.8 4.7 6.7 76.5 4.9 6.9 -4A 4N 227-29 79.0 5.3 7.3 79.6 5.1 7.1 -5A 5N 233-34 76.6 4.7 5.3 76.8 4.7 5.6 -6A 6N 178-80 76.7 4.8 5.6 76.8 4.7 5.6 -7A' 18A 172-74 25 77.2 4.8 5.6 76.8 4.7 5.6 -SAC 1 9b,d 168-70 12 77.0 4.4 4.7 77.0 4.7 4.7 -9A 9N 221 75 ------6O4( 604) 1 OA 1 ON 159.5-63.5 71.7 4.5 4.1 71.3 4.4 4.4 640(640) 11A 11N 201-03 77.3 4.1 3.6 77.95 4.55 4.0 -12A 12N 246-50 78.0 4.6 4.1 77.95 4.55 4.0 -13A 13N 200-01 52 77.9 4.5 3.9 77.95 4.55 4.0 -14A 14N (dec.) 50 80.4 3.4 5.0 80.9 3.7 4.8 756( 756) 15A 15N 231-34 77.3 4.7 3.3 77.6 4.6 3.6 788( 788) 16A' 20 dec 280 76.7 4.7 3.0 77.6 4.6 3.6 ~ 18A 18N 124-26d 37 72.2 4.2 6.5 72.5 4.6 6.5 -" Lit.? mp 177-78 "C.Lit.:6 mp 150-51 "C. 'see Table 4. dLit.:7 mp 129-30 "C. 0.048 mol) and potassium carbonate (13.82 g, 0.1 mol) were added and the mixture was refluxed until TLC showed complete consumption of the resorcinol. The cooled mixture was poured into ice-water (200 ml), causing a green oil to deposit. The aqueous layer was decanted off and the residual oil was heated with 2 mol 1-l hydrochloric acid (200 ml), producing an insoluble hydrochloride.This was collected by filtration and washed with water (500 ml). Addition to 2 mol 1-1 sodium hydroxide (500ml) regenerated the amine as a green solid which was collected, dried, and crystallised from toluene-ethanol to give the product (6.0 g, 25%) (see Table 4). Dimethylformamide and dimethylacetamide were substi-tuted as solvents for the syntheses of amines 8A and 16A, respectively. Amine 7A was the only one for which the above purification uia the hydrochloride was necessary. The others prepared by this route (Table 4) separated as solids when the reaction mixtures were poured on ice; they were therefore collected by filtration, washed and recrystallised directly. Typical reaction times were 2-3 h.'H NMR Data [in(CD,),SO unless otherwise specified] Compound (2N): 7.40 (4 H, dd, J 7.8, 2), 7.97 (1H, t, J 7.8), 8.00 (2 H, dd, J 7.8, 2), 8.08 (2 H, dd, J 7.8, 2), 8.27 (1 H, d, J7.8),8.47(2H,d,J7.8),8.57(1H,d,J7.8),8.57(1H,s). Compound (4N): 8.03 (4 H, d, J 9), 8.09 (4 H, d, J9), 8.12 (4 H, d, J 9), 8.49 (4 H, d, J 9). Compound (11N): 7.27 (4 H, d, J 9), 7.28 (4 H, d, J 7.5 7.78 (1H, t, J 7.7), 7.85 (4 H, d, J 8.8), 7.90 (4 H, d, J 8.8), 7.94 (4 H, d, J 8.8), 7.99 (1 H, s), 8.04 (2 H, d, J 7.7), 8.36 (4 H, d, J 8.8). Compound (18N): 7.45 (2 H, dd, J 8.5, 7.5), 7.90 (2 H, dd, J 8.5, 5), 8.00 (2 H, d, J 9), 8.42 (2 H, d, J 9). Compound (1A): 6.10 (4 H, s), 6.64 (4 H, d, J 8), 7.21 (4 H, d, J 8), 7.58 (4 H, d, J 8), 7.72 (4 H, d, J 8).Compound (2A): 5.40 (2 H, s), 6.16 (2 H, s), 6.60 (2 H, d, J8.7)6.81 (2H,dd, J7.8,2),6.94(lH, t, J2),7.17(1H, t, J 7.6), 7.21 (4H, dd, J 6.8, 2), 7.34 (2H, d, J8.7), 7.70 (2H, dd, J 6.8, 2), 7.79 (2 H, dd, J 6.8, 2). Compound (3A): 5.40 (4H, s), 6.82 (4 H, dd, J 8, 2), 6.94 (2 H, t, J 2), 7.16 (2 H, t, J 8), 7.24 (4 H, d, J 8.5), 7.81 (4 H, d, J 8.5). Compound (4A): 5.84 (4 H, s), 6.68 (4 H, d, J 9), 7.58 (4 H, d, J 9), 7.73 (4 H, d, J 9), 7.86 (4 H, d, J 8). Compound (5A): 6.20 (4 H, s), 6.59 (4 H, d, J 7), 7.08 (4 H, d, J 7), 7.22 (4 H, s), 7.52 (4 H, d, J 7), 7.66 (4 H, d, J 7). Compound (6A): 5.38 (4 H, s), 6.80 (4 H, d, J 8), 6.91 (2 H, s), 7.10 (4H, d, J 6.7), 7.18 (2 H, d, J 7.8), 7.25 (4 H, s), 7.76 (4 H, d, J 6.7).Compound (7A): 6.12 (4H, s), 6.59 (4H, d, J8.62), 6.87 (lH, t, J2.3), 6.94 (2H, dd, J8.2, 2.3) 7.12 (4H, d, J8.64), 7.49 (1H, t, J 8.7), 7.51 (4 H, dd, J 8.62,2), 7.66 (4 H, d, J 8.46). Compound (8A): 5.32 (4 H, s), 6.23 (2 H, dd, J 7.9, 2), 6.29 (2 H, t, J 2), 6.42 (2 H, dd, J 7.9, 2), 7.06 (2H, t, J 7.9), 7.07 (4 H, d, J 8.8), 7.25 (4 H, d, J 8.8), 7.78 (4 H. d, J 8.8), 7.81 (4 H, d, J 8.8). Compound (11A): 6.16 (4 H, s), 6.60 (4 H, d, J 8.8), 7.20 (4H, d, J 8.8), 7.24 (4H, d, J 8.8), 7.53 (4 H, d, J 8.8), 7.68 (4H, d, J8.8), 7.77 (1 H, t, J 8.8), 7.88 (4 H, d, J 8.8), 8.00 (2 H, d, J 8.8), 8.05 (1H, s). Compound (12A): 5.41 (4 H, s), 6.82 (4 H, dd, J 7.7, 2), 6.95 (2H, t, J 1.8), 7.18 (2 H, t, J 7.7), 7.26 (4 H, d, J 8.8), 7.27 (4 H, d, J 8.8), 7.82 (4 H, d, J 8.8), 7.89 (4H, s), 7.90 (4 H, d, J 8.8).Compound (13A): 5.40 (4 H, s), 6.82 (4 H, d, J 8), 6.95 (2 H, t, J2), 7.17 (2 H, t, J8), 7.24 (4 H, d, J 6.5). 7.27 (4 H, d, J 6.5), 7.78 (1 H, t, J 7.2), 7.81 (4 H, d, J 6.8), 7.90 (4 H, d, J 6.8), 8.01 (1H, s), 8.03 (2 H, d, J 7.2). Compound (18A): (in CDC13) 4.09 (2 H, s), 6.69 (2H, d, J9.3), 7.15 (2H, dd, J 8.5 Hz, 7.5 Hz), 7.69 (2 H, d, J9.3), 7.86 (2 H, dd, J 8.5, 7.5). Compound (17A): 7.23 (2 H, d, J 7.8), 7.26 (2 H, d, J 9), 7.36 (1 H, t, J 7.5), 7.58 (2 H, d, J 9), 7.95 (2 H, d, J 7.8), 7.96 (lH, t, J7.8), 8.24 (lH, d, J7.8), 8.54 (1H. s), 8.56 (lH, d, J 7.8). Compound (19a): (in CDC1,) 7.16 (4 H, d, J 8.9), 7.30 (2 H, dm), 7.48 (4 H, m), 7.57 (2 H, dt, J 6.3, 1.4), 7.88 (4 H, d, J 8.9).The authors thank ICI plc for supporting this work; A.J.L. also thanks SERC for a CASE studentship. P.L.P. thanks the Leverhulme Trust for the award of an Emeritus Fellowship which enabled him to participate in this work. D.C.S.acknowl-edges receipt of a Visiting Professorship at Tokyo Institute of WPTable 3 Synthesis of intermediates by Friedel-Crafts reactions W (a) From 3- or 4-nitrobenzoyl chlorides and arenes found (YO) calcd. (YO) reaction product yield mP solvent for mlz P chloride arene ratio time".b no. formula (%I 1°C C H N C H N recryst. found (theor.) -4-PhOPh 2: 1 18" 1N C26H16N207 51 226' 66.5 3.2 5.7 66.7 3.4 6.0 PY -3-PhOPh 1: 1 1" 80 94-96d 71.4 4.0 4.4 71.5 4.1 4.4 EtOH -4-PhOPh 1 :1.85 18" c19H 13N04 54 122" 71.5 4.0 4.2 71.5 4.1 4.4 EtOH 4-17a 1: 1 1" 81 179-8 1 66.9 3.4 5.9 66.7 3.4 6.0 DMF aq.-3-PhOPh 2: 1 18b 53 175' 66.5 3.3 5.8 66.7 3.4 6.0 EtOAc -4-PhPh 2.2: 1 4a.g 4N 33 211-12 69.3 3.5 6.2 69.0 3.5 6.2 DMF -4-4-PhOCsH4OPh 2: 1 2" 89 218-19 68.0 3.6 5.1 68.6 3.6 5.0 DMF aq. -E}3-2: 1 2" 77 201-03 68.4 3.6 4.8 68.6 3.6 5.0 3-2.2: 1 2.5" 9N 89 230 -----__ NMP aq. 664( 664) 4-1: 1 2" 18N 57 86-88' 64.2 3.1 5.7 63.7 3.2 5.7 EtOH -3-2.2: 1 2.5" 14N 95 257 -816(816) 3-2.2: 1 2.5" 15N 93 247.5 -848( 848) 3-2.2: 1 2.5" 1ON 93 189 -700( 700) (b)From other aroyl chloridesh ___ ~____ found (YO) calcd. (%) reaction product yield mP solvent mlz chloride arene ratio time"Sb no. formula (%I /"c C H N C H N recrystn.found (theor.) 3F PhOPh 2: 1 2" 19a C26H16N203 50 156-58 75.8 3.8 75.4 3.9 3.65 PhMe -4F (PhOC6H4),C0 2.2: 1 1" C39H24F205 85 279 -------612(610) tere 17b 1:2 6" 35 282-83 71.1 3.4 3.4 71.9 3.7 3.65 --tere 17a 1:2 6" 33 272 71.2 3.6 3.7 71.9 3.7 3.65 -__ is0 17b 1:2 6" 11N C46H28N2010 57 211-12 71.6 3.6 3.1 71.9 3.7 3.65 --is0 17a 1:2 6" 13N 73 218-19 72.1 3.7 3.7 71.9 3.7 3.65 --"h at reflux in 1,2-CzH,Cl2. "h at room temp. in CH2C12. Lit. :ti mp 226 "C. Lit. : mp 87-88 "C. " Lit. : mp 121-122 "C. f Lit. : mp 175 "C. Busing FeC13 in place of AlCl,. 3-F =3-fluorobenzoyl; 4-F = 4-fluorobenzoyl; tere =terephthaloyl; is0 =isophthaloyl. Lit. : mp 88-88.5 "C. J. MATER. CHEM., 1994, VOL. 4 Table 4 Ullmann ether syntheses fluoroarene or nitroarene phenol yield (YO) (4-FC,H,)ZCO PhOH 94 (~-FC,H~)ZSOZ(4-FC6H,)zCO (4-FC6H4)ZCO PhOH 4-PhOC6HdOH 4-PhC6HdOH 89 89 73 18A 19b 1,3-C6H4(OH)z 1,3-HOC,H,NHZ 25 12 20 1,3-HOC6H,NH, 70 “ Lit.:9 mp 146-147 “C.Technology funded by Monbusho which allowed completion of this manuscript. References 1 D. M. Hergenrother, N. T. Wakelyn and S. J. Havers, J. Polym. Sci.:Polym. Chem. Ed., 1987,25, 1093. 2 G. Eastmond, J. Paprotny and I. Webster, Polymer, 1993,34,2865. 3 Parts 1 and 2: J. Muter. Chem., 1994,4, 1511;1521. mlz mp/”C product found (theor.) 147“ (1,4-PhOC,jH4)zCO 366( 366) 142 1,4-PhOC,H4),SO, 402( 402) 199 197-99 172-74 (1,4-PhOC&0C6H4)zCO (1 ,4-PhC,H,OC,H,),CO 7A 548(550) 516( 518) - 168-70 8A - 280 16A 788(788) 4 F. Ullmann and P. Sponagel, Justus Liebig’s Ann. Chem., 1906, 350, 83. 5 P. M. Hergenrother, B. J. Jensen and S. J. Havens, Polymer, 1988, 29, 358. 6 W. Dilthey, C. Blankenburg, W. Braun, R. Dinklage, W. Huthwelker and W.Schommer,J. Prukt. Chem., 1931,129,189. 7 B. Staskun, J. Org. Chem., 1964,29,2856. 8 R. G. Pews, Y. Tsuno and R. W. Taft, J. Am. (‘hem. Soc., 1967, 89,2391. 9 W. Tadros and A. Latif, J. Chem. SOC.,1949,3337. Paper 4/02561J; Received 29th April, 1994.