Silicon-Containing Polyureas
FULL PAPER
with a Pyrex glass filter, at room temperature under nitrogen for 12 h.
The resultant solution was concentrated under reduced pressure to give a
residue that was purified by performing column chromatography (10%
EtOAc in hexanes as eluant). N-Methylurea 9b (37.6 mg, 0.162 mmol)
was obtained in 72% yield as white solids. M.p. 195–1968C (published
m.p. 195–1978C[31]); TLC Rf: 0.68 (30% EtOAc in hexanes as eluant);
1H NMR (CDCl3, 400 MHz): d=1.04–1.82 (m, 10H; 5ꢁCH2), 2.84 (s,
3H; CH3), 4.02–4.14 (m, 1H; CHN), 6.38–6.42 (br, 1H; NH), 6.99 (t, J=
7.6 Hz, 1H; ArH), 7.26 (t, J=7.6 Hz, 2H; 2ꢁArH), 7.38 ppm (d, J=
8.4 Hz, 2H; 2ꢁArH); 13C NMR (CDCl3, 75 MHz): d=25.49, 25.72, 28.48,
30.48, 54.04, 119.79, 122.71, 128.71, 139.33, 155.17 ppm (C=O); IR (neat)
3302 (s, N-H), 2929 (s), 2853 (s), 1638 (s, C=O), 1594 (s), 1527 (s), 1441
(s), 1322 (m), 1168 (m), 879 (m), 753 (m), 697 cmꢀ1 (m); MS m/z (relative
intensity): 232 (16) [M+], 140 (12), 120 (8), 112 (100), 97 (9), 77 (15), 55
(25).
N,N’-Dicyclohexyl-N-methylurea (9c):[32] A solution of urea 8c (88.5 mg,
0.285 mmol) in CHCl3/MeOH (9:1, 5.0 mL) was irradiated with UV light
by using a medium-pressure mercury lamp (450 W) equipped with a
Pyrex glass filter, at room temperature under nitrogen for 12 h. The re-
sultant solution was concentrated under reduced pressure to give a resi-
due that was purified by performing column chromatography (10%
EtOAc in hexanes as eluant). N-Methylurea 9c (8.8 mg, 0.037 mmol) was
obtained in 13% yield as white solids. M.p. 106–1078C (published m.p.
106–1098C[32]); TLC Rf: 0.70 (30% EtOAc in hexanes as eluant);
1H NMR (CDCl3, 400 MHz): d=0.99–1.41 (m, 10H; 5ꢁCH2), 1.51–1.96
(m, 10H; 5ꢁCH2), 2.63 (s, 3H; CH3), 3.47–3.62 (m, 1H; CHN), 3.86–3.97
(m, 1H; CHN), 4.08–4.21 ppm (br, 1H; NH); 13C NMR (CDCl3,
75 MHz): d=25.02, 25.54, 25.64, 25.75, 28.02, 30.45, 34.02, 49.29, 53.61,
157.20 ppm (C=O); IR (neat) 3303 (m, N-H), 2925 (m), 2851 (m), 1619
(s, C=O), 1537 (s), 1453 (s), 1391 (s), 1223 (s), 1038 (s), 893 (s), 744 (m),
629 cmꢀ1 (w); MS m/z (relative intensity): 238 (23) [M+], 155 (8), 112
(100), 97(13), 83 (9).
methylsilane 11 (50.5 mg, 0.187 mmol, 0.1 equiv), dianilino-p-xylene (15,
483.8 mg, 1.680 mmol, 0.9 equiv), sym-tetrachloroethane (1.8 mL), and
isocyanate 16 (467.2 mg, 1.867 mmol, 1 equiv). After purification, 17b
(911.4 mg, 1.698 mmol) was obtained in 91% yield as white elastomers,
which were soluble in THF and chloroform. Data for 17b: 1H NMR
(CDCl3, 400 MHz): d=0.017 (s, 6H; Si(CH3)2, 6%), 3.27 (s, 4H; 2ꢁ
SiCH2N, 6%), 3.77 (s, 4H; 2ꢁArCH2Ar), 4.84 (s, 4H; 2ꢁNCH2Ar), 6.07
(s, 4H; 4ꢁNH), 6.95–7.38 ppm (brm, 40H; 40ꢁArH); IR (neat) 3425
(m, NH), 3345 (m, NH), 3008 (m), 2921 (w), 1677 (s, C=O), 1593 (s),
1514 (s), 1411 (s), 1309 (s), 1248 (m, Si-CH3), 1019 (m), 811 (m), 756 (s),
701 cmꢀ1 (s); UV/Vis (CHCl3): lmax, (e)=249 nm (241); Mw 5.49ꢁ104; Mn
2.39ꢁ104; Tg 1218C.
Poly[bis(anilinomethyl)dimethylsilane-co-dianilino-p-xylene-co-4,4’-meth-
ylenebis(phenylisocyanate)] (17c) from bis(anilinomethyl)dimethylsilane
(11, 0.2 equiv): The standard procedure 2 was followed by using anilino-
methylsilane 11 (121.8 mg, 0.451 mmol, 0.2 equiv), dianilino-p-xylene (15,
519.0 mg, 1.802 mmol, 0.8 equiv), sym-tetrachloroethane (2.1 mL), and
isocyanate 16 (563.8 mg, 2.253 mmol, 1 equiv). After purification, 17c
(1.08 g, 2.02 mmol) was obtained in 90% yield as white elastomers:
1H NMR (CDCl3, 400 MHz): d=0.017 (s, 6H; Si(CH3)2, 12%), 3.28 (s,
4H; 2ꢁSiCH2N, 12%), 3.77 (s, 4H; 2ꢁArCH2Ar), 4.85 (s, 4H; 2ꢁ
NCH2Ar), 6.08 (s, 4H; 4ꢁNH), 6.96–7.40 ppm (brm, 40H; 40ꢁArH); IR
(neat) 3426 (m, NH), 3345 (m, NH), 3007 (m), 2922 (w), 1679 (s, C=O),
1593 (s), 1518 (s), 1411 (s), 1308 (s), 1251 (m, Si-CH3), 1023 (m), 814 (m),
758 cmꢀ1 (s); UV/Vis (CHCl3): lmax, (e)=251 nm (243); Mw 5.21ꢁ104; Mn
2.17ꢁ104; Tg 1188C.
Poly[bis(anilinomethyl)dimethylsilane-co-dianilino-p-xylene-co-4,4’-meth-
ylenebis(phenylisocyanate)] (17d) from bis(anilinomethyl)dimethylsilane
(11, 0.3 equiv): The standard procedure 2 was followed by using anilino-
methylsilane 11 (101.4 mg, 0.376 mmol, 0.3 equiv), dianilino-p-xylene (15,
252.6 mg, 0.877 mmol, 0.7 equiv), sym-tetrachloroethane (1.8 mL), and
isocyanate 16 (313.6 mg, 1.253 mmol, 1 equiv). After purification, 17d
(607.5 mg, 1.135 mmol) was obtained in 91% yield as white elastomers:
1H NMR (CDCl3, 400 MHz): d=0.019 (s, 6H; Si(CH3)2, 15%), 3.29 (s,
4H; 2ꢁSiCH2N, 15%), 3.77 (s, 4H; 2ꢁArCH2Ar), 4.86 (s, 4H; 2ꢁ
NCH2Ar), 6.07 (s, 4H; 4ꢁNH), 6.95–7.42 ppm (brm, 40H; 40ꢁArH); IR
(neat) 3428 (m, NH), 3348 (m, NH), 3009 (m), 2921 (w), 1677 (s, C=O),
1594 (s), 1518 (s), 1413 (s), 1310 (s), 1255 (m, Si-CH3), 1026 (m), 818 (m),
762 cmꢀ1 (s); UV/Vis (CHCl3): lmax, (e)=250 nm (244); Mw 5.05ꢁ104; Mn
1.68ꢁ104; Tg 1138C.
2,2-Dimethyl-N,N’-diphenyl-1,3-propanediamine (14): Lithium aluminum
hydride (53.4 mg, 1.41 mmol) was added to a solution of diamide 13
(158.7 mg, 0.5628 mmol, 1 equiv) in THF (20 mL). The reaction mixture
was heated at reflux under nitrogen for 16 h, then quenched with saturat-
ed aqueous Na2SO4 (5.0 mL) at 08C, and extracted with Et2O (3ꢁ
20 mL). The combined organic layers were washed with saturated aque-
ous NaCl (5.0 mL), dried over MgSO4 (s), filtered, and concentrated
under reduced pressure. The residue was purified by performing column
chromatography (10% EtOAc in hexanes as eluant). Diamine 14
(127.2 mg, 0.5008 mmol) was obtained in 89% yield as yellow solids. M.p.
(recrystallized from ethanol) 80–818C; GC tR: 11.47 min; TLC Rf: 0.71
(20% EtOAc in hexanes as eluant); 1H NMR (CDCl3, 400 MHz): d=
1.09 (s, 6H; 2ꢁCH3), 3.07 (s, 4H; 2ꢁCH2N), 3.79 (br, 2H; 2ꢁNH), 6.63
(d, J=8.2 Hz, 4H; 4ꢁArH), 6.70 (t, J=7.4 Hz, 2H; 2ꢁArH), 7.17 ppm
(dd, J=8.2, 7.4 Hz, 4H; 4ꢁArH); 13C NMR (CDCl3, 75 MHz): d=24.15,
35.54, 52.92 (CH2N), 112.89, 117.29, 129.14, 148.71 ppm; IR (neat) 3295
(m, N-H), 3057 (w), 2956 (m), 1603 (s), 1495 (s, Ph), 1303 (m), 1187 (m),
1068 (m), 877 (m), 754 (s), 693 cmꢀ1 (s); MS m/z (relative intensity): 254
(60) [M+], 146 (36), 132 (10), 119 (8), 106 (100), 93 (95), 77 (43); HRMS
calcd for C17H22N2: 254.1783; found: 254.1780; elemental analysis calcd
(%) for C17H22N2: C 80.26, H 8.72, N 11.02; found: C 80.22, H 8.68, N
10.97.
Poly[bis(anilinomethyl)dimethylsilane-co-dianilino-p-xylene-co-4,4’-meth-
ylenebis(phenylisocyanate)] (17e) from bis(anilinomethyl)dimethylsilane
(11, 0.35 equiv): The standard procedure 2 was followed by using anilino-
methylsilane 11 (101.0 mg, 0.374 mmol, 0.35 equiv), dianilino-p-xylene
(15, 200.2 mg, 0.695 mmol, 0.65 equiv), sym-tetrachloroethane (1.8 mL),
and isocyanate 16 (267.5 mg, 1.069 mmol, 1 equiv). After purification,
17e (511.8 mg, 0.9565 mmol) was obtained in 90% yield as white elasto-
mers: 1H NMR (CDCl3, 400 MHz): d=0.017 (s, 6H; Si(CH3)2, 16%),
3.28 (s, 4H; 2ꢁSiCH2N, 16%), 3.77 (s, 4H; 2ꢁArCH2Ar), 4.84 (s, 4H;
2ꢁNCH2Ar), 6.09 (s, 4H; 4ꢁNH), 6.96–7.41 ppm (brm, 40H; 40ꢁArH);
IR (neat) 3425 (m, NH), 3348 (m, NH), 3006 (m), 2922 (w), 1678 (s, C=
O), 1591 (s), 1519 (s), 1411 (s), 1309 (s), 1253 (m, Si-CH3), 1020 (m), 816
(m), 758 cmꢀ1 (s); UV/Vis (CHCl3): lmax, (e)=249 nm (245); Mw 4.06ꢁ
104; Mn 1.31ꢁ104; Tg 1088C.
Standard procedure 2 for the synthesis of polyureas 17 by addition of di-
anilino compounds to diisocyanate: 4,4’-Methylenebis(phenylisocyanate)
(16) (0.10–0.40 equiv)) was added to a solution of anilinomethylsilane 11
and dianilino-p-xylene (15) (0.60–0.90 equiv) in sym-tetrachloroethane
(1.8 mL) and the reaction mixture was stirred under nitrogen at 1008C
for 12 h. The resultant viscous solution of polymers was diluted with sym-
tetrachloroethane (5.0 mL) and poured into MeOH (80 mL) to give a
precipitate, which was redissolved in chloroform (5.0 mL). This precipita-
tion procedure was repeated twice. The precipitate was dried over phos-
phorous pentoxide under reduced pressure at room temperature for 24 h
to provide the desired polyureas 17.
Poly[bis(anilinomethyl)dimethylsilane-co-dianilino-p-xylene-co-4,4’-meth-
ylenebis(phenylisocyanate)] (17 f) from bis(anilinomethyl)dimethylsilane
(11, 0.4 equiv): The standard procedure 2 was followed by using anilino-
methylsilane 11 (137.6 mg, 0.510 mmol, 0.4 equiv), dianilino-p-xylene (15,
220.3 mg, 0.765 mmol, 0.6 equiv), sym-tetrachloroethane (1.8 mL), and
isocyanate 16 (319.1 mg, 1.275 mmol, 1 equiv). After purification, 17 f
(595.8 mg, 1.115 mmol) was obtained in 88% yield as white elastomers:
1H NMR (CDCl3, 400 MHz): d=0.018 (s, 6H; Si(CH3)2, 21%), 3.28 (s,
4H; 2ꢁSiCH2N, 21%), 3.78 (s, 4H; 2ꢁArCH2Ar), 4.85 (s, 4H; 2ꢁ
NCH2Ar), 6.07 (s, 4H; 4ꢁNH), 6.98–7.42 ppm (brm, 40H; 40ꢁArH); IR
(neat) 3422 (m, NH), 3341 (m, NH), 3010 (m), 2924 (w), 1677 (s, C=O),
1590 (s), 1516 (s), 1412 (s), 1307 (s), 1254 (m, Si-CH3), 1025 (m), 820 (m),
756 cmꢀ1 (s); UV/Vis (CHCl3): lmax, (e)=249 nm (246); Mw 2.86ꢁ104; Mn
8.15ꢁ103; Tg 1048C.
Poly[bis(anilinomethyl)dimethylsilane-co-dianilino-p-xylene-co-4,4’-meth-
ylenebis(phenylisocyanate)] (17b) from bis(anilinomethyl)dimethylsilane
(11, 0.1 equiv): The standard procedure 2 was followed by using anilino-
Chem. Eur. J. 2005, 11, 3805 – 3815
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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