M. J. Plater, T. Jackson / Tetrahedron 59 (2003) 4687–4692
4691
4.1.4. N,N-Di(4-tolyl)-40-(ethynyl)phenylamine 2. N,N-
Di(4-tolyl)-40-iodophenylamine 5 (4.0 g, 10.0 mmol) was
dissolved in dry, degassed NEt3 (20 mL) under nitrogen. To
this was added trimethylsilylacetylene (1.70 mL,
12.0 mmol), bis(triphenylphosphine)palladium(II) chloride
(35 mg) and copper iodide (5 mg). The mixture was refluxed
at 668C under nitrogen with stirring for 2 h. The mixture was
cooled and poured into distilled H2O (100 mL), extracted
with CH2Cl2, dried over MgSO4 and solvents were removed
under reduced pressure. The residues were dissolved in
dichloromethane/light petroleum and filtered through silica
and the solvent removed. The resultant yellow oil was then
dissolved in dry MeOH to which K2CO3 (1.38 g,
10.0 mmol) was added and the mixture left to stir under
nitrogen for 18 h. The MeOH was removed under reduced
pressure and the residues were dissolved in CH2Cl2, washed
with distilled H2O (£2), dried over MgSO4 and the CH2Cl2,
removed under reduced pressure. Column chromatography,
eluting with dichloromethane/light petroleum (15:85)
yielded an orange oil which recrystallised on standing to
give the title compound (1.73 g, 62%) as an orange
crystalline solid, mp 95–968C. lmax (CH2Cl2)/nm 326
(log 1 5.73); nmax (KBr)/cm21 3310w, 3283s, 3026m,
2922m, 2854m, 2101m, 1597s, 1499s, 1381w, 1320s,
1292s, 1268s, 1213m, 1175m, 1109m, 1015w, 816s,
714w, 655m, 608m and 551m; dH (250 MHz; CDCl3) 2.31
(6H, s, Me), 2.99 (1H, s, ethynyl), 6.87–6.91 (2H, d,
J¼9.2 Hz, Ar), 6.97–7.01 (4H, d, J¼8.4 Hz, Ar) and 7.06–
7.09 (4H, d, J¼8.3 Hz, Ar), 7.26–7.30 (2H, d, J¼9.1 Hz);
dC (62.9 MHz; CDCl3) 20.9, 75.8, 84.2, 113.7, 120.8, 125.3,
130.1, 133.0, 133.4, 144.6 and 148.8; m/z 297 (Mþ, 100%).
copper iodide and bis(triphenylphosphine)palladium(II)
chloride were added. With stirring in a strictly nitrogen
atmosphere the mixture was refluxed at 898C for 1 h. After
cooling the reaction mixture was washed with distilled H2O
(£2) and dried over MgSO4. Solvents were removed under
reduced pressure. Column chromatography, eluting with
dichloromethane/light petroleum (25:75) yielded two pro-
ducts. The more polar fraction was recrystallised from
dichloromethane/light petroleum to give the title compound
(0.22 g, 49%) as a yellow crystalline solid, mp 244–2458C.
(Found: C, 90.1; H, 6.2; N, 3.9. C50H40N2 requires C, 89.8;
H, 6.0; N, 4.2%); lmax (CH2Cl2)/nm 295 (log 1 4.98) and
382 (5.47); nmax (KBr)/cm21 3045m, 2917m, 2211m,
1589s, 1515s, 1490s, 1402w, 1382w, 1316s, 1289s,
1231m, 1177m, 1147m, 1122w, 1028w, 881w, 836s,
749m, 720w, 693m and 625w; dH (250 MHz; CDCl3) 2.01
(6H, s, Me), 2.34 (6H, s, Me), 6.84–6.88 (4H, d, J¼8.9 Hz,
Ar), 6.94–7.07 (9H, m, Ar), 7.20–7.30 (7H, m, Ar), 7.30–
7.34 (4H, d, J¼9.0 Hz, Ar) and 7.44 (4H, s, Ar); dC
(100.5 MHz; CDCl3): 19.4, 22.1, 89.2, 92.7, 115.4, 120.6,
123.4, 123.7, 124.1, 129.3, 130.2, 130.5, 132.3, 133.5,
133.6, 137.3, 143.1, 147.7 and 148.8 (one overlapping
peak); m/z 668 (Mþ, 100%). Additionally 4-[N-(2,4-
dimethyl)-N-phenyl-4-(ethynyl)phenylamine]iodobenzene
was isolated and recrystallised from dichloromethane/light
petroleum (0.11 g, 32%), mp 89–908C.
nmax (KBr)/cm21 3033m, 2916m, 2856w, 2208m, 1591s,
1505s, 1492s, 1388w, 1313s, 1289s, 1268s, 1231m, 1174m,
1135m, 1056w, 1004m, 880w, 816s, 755s, 731m, 694s,
597w, 572m and 516m; dH (250 MHz; CDCl3) 2.00 (6H, s,
Me), 2.34 (3H, s, Me), 6.83–6.87 (2H, d, J¼9.0 Hz, Ar),
6.94–7.07 (5H, m, Ar), 7.19–7.33 (7H, m, Ar) and 7.63–
7.67 (2H, d, J¼9.1 Hz Ar); dC (100.5 MHz; CDCl3) 19.4,
22.1, 88.4, 92.5, 94.4, 115.1, 120.5, 123.5, 123.7, 124.4,
129.3, 130.2, 130.5, 133.5, 133.6, 134.0, 137.3, 137.3,
138.5, 143.0, 147.6 and 148.9; m/z 499 (Mþ, 100%).
4.1.5. N,N0-Diphenyl-N,N0-bis(2,4-dimethylphenyl)-4-
(diethynyl)diphenyldiamine 8. In a dry flask N-(2,4-
dimethyl)phenyl-N-phenyl-4-(ethynyl)phenylamine
1
(0.20 g, 67.3 was dissolved in dry THF (25 mL) and Et3N
(5 mL). To this was added bis(triphenylphosphine)pal-
ladium(II) chloride (10 mg) and copper iodide (3 mg). The
reaction mixture was refluxed at 658C under nitrogen with
stirring for 1 h. Once cooled the reaction mixture was
washed in distilled H2O (£2), extracted with CH2Cl2, dried
over MgSO4 and the solvents removed under reduced
pressure. Column chromatography, eluting with dichlor-
omethane/light petroleum (15:85) yielded a viscous yellow/
orange oil which solidified on complete removal of solvent
(50 mg, 25%) as an orange solid, mp 79–808C. lmax
(CH2Cl2)/nm 297 (log 1 5.45) and 371 (6.71); nmax (KBr)/
cm21 3035w, 2953w, 2917w, 2855w, 2144w, 1601w,
1590s, 1497s, 1383w, 1315s, 1291m, 1231m, 1171m,
1124w, 1028w, 826m, 752w, 694m and 622w; dH
(250 MHz; CDCl3): 2.08 (6H, s, Me), 2.43 (6H, s, Me),
6.74–6.87 (4H, d, J¼9.1 Hz, Ar), 6.97–7.13 (10H, m, Ar),
7.18–7.28 (6H, m, Ar) and 7.29–7.33 (4H, d, J¼9.1 Hz,
Ar); dC (100.5 MHz; CDCl3) 18.3, 21.1, 73.2, 82.1, 112.9,
119.1, 122.8, 123.0, 128.3, 129.2, 129.5, 132.5, 133.4,
136.3, 136.5, 141.8, 146.3 and 148.2; m/z 592 (Mþ, 100%).
Accurate mass: calculated 593.2957, found 593.2918.
4.1.7. 4,40-Bis[N-(2,4-dimethyl)-N-phenyl-4-(ethynyl)-
phenylamine]-N,N-diphenyltolylamine
procedure as for 9. N-(2,4-Dimethyl)-N-phenyl-4-(ethynyl)-
phenylamine (0.25 g, 0.862 mmol), N,N-di(4-iodo-
10.
General
1
phenyl)-tolylamine 6 (0.15 g, 0.431 mmol), Et3N (20 mL),
copper iodide and bis(triphenylphosphine)palladium(II)
chloride in catalytic quantities were refluxed for 1 h. Yield
24%; yellow crystalline solid, mp 117–1188C (from light
petroleum). lmax (CH2Cl2)/nm 280 (log 1 5.25) and 388
(6.20); nmax (KBr)/cm21 3036m, 2954m, 2916m, 2863m,
1597s, 1508s, 1490s, 1377w, 1318s, 1289s, 1231m, 1175m,
1108w, 1030w, 918w, 876w, 829s, 735m, 721m, 694s, 572s,
521m and 456w; dH (250 MHz; CDCl3) 1.99 (6H, s, Me),
2.34 (9H, s, Me), 6.84–6.87 (4H, d, J¼8.2 Hz, Ar), 6.92–7.11
(20H, m, Ar), 7.18–7.22(4H, d, J¼8.1 Hz, Ar) and 7.28–7.35
(8H, m, Ar); dC (100.5 MHz; CDCl3) 19.4, 21.9, 22.1, 89.3,
90.3, 116.0, 118.3, 120.8, 123.2, 123.5, 123.9, 126.8, 129.3,
130.2, 130.5, 131.2, 133.3, 133.4, 133.5, 135. 0, 137.2, 137.3,
143.2, 145.2, 147.8, 148.1 and 148.4; m/z 849 (Mþ, 100%).
Accurate mass: calculated 849.4943, found 849.4955.
4.1.6. 1,4-Bis[N-(2,4-dimethyl)-N-phenyl-4-(ethynyl)-
phenylamine]benzene 9. N-(2,4-Dimethyl)-N-phenyl-4-
(ethynyl)phenylamine 1 (0.40 g, 1.37 mmol) and diiodo-
benzene (0.22 g, 0.667 mmol) were dissolved in dry,
degassed Et3N (25 mL) to which catalytic amounts of
4.1.8. 4,40-Bis[N,N-di(tolyl)-40-(ethynyl)phenylamine]-
N,N-diphenyltolylamine 11. General procedure as for
9. N,N-Di(4-tolyl)-40-(ethynyl)phenylamine
1.68 mmol) and N,N-di(4-iodophenyl)tolylamine 6 (0.29 g,
2
(0.50 g,