1854
I. D. Kostas et al. / Tetrahedron Letters 50 (2009) 1851–1854
GC–MS (EI): m/z (relative intensity) 243 (M+, 100), 116 ([M–I]+, 21),
89 (17), 63 (8). Anal. Calcd for C8H6IN: C, 39.53; H, 2.49; N, 5.76.
Found: C, 39.78; H, 2.57; N, 5.53.
2,4,6-Tris(4-iodo-3-methyl-phenylene)-1,3,5-triazine (7): Reac-
tion of 6 (2.16 g, 8.89 mmol) with trifluoromethanesulfonic acid
(2.80 mL, 31.64 mmol) as described for the synthesis of 2 yielded
7 as a white solid (1.61 g, 75%).17 1H NMR (300.13 MHz, CD2Cl2):
d 8.60 (s, 3H, ArH), 8.26–8.23 (m, 3H, ArH), 8.06 (d, 3J = 8.0 Hz,
3H, ArH), 2.62 (s, 9H, CH3). Anal. Calcd for C24H18I3: C, 39.53; H,
2.49; N, 5.76. Found: C, 39.40; H, 2.24; N, 5.84.
Dendritic molecule 8: A solution of 7 (0.25 g, 0.34 mmol), 5 (0.85 g,
1.34 mmol) and Pd(PPh3)4 (0.06 g, 0.05 mmol) in o-xylene (25 mL)
and aqueous Na2CO3 (2 M, 2.60 mL, 5.20 mmol) was refluxed under
argon for 3 d. After cooling to room temperature, the mixture was
quenched with saturated aqueous NH4Cl solution (50 mL) and di-
luted with dichloromethane (300 mL). The organic layer was sepa-
rated, washed with water (50 mL) and dried over Na2SO4. After
filtration, the filtrate was passed through a pad of Celite and the sol-
vents were removed by evaporation. Column chromatography over
silica gel using dichloromethane/hexane (1:1) as eluent yielded 8 as
a white solid (0.40 g, 79%).17 1H NMR (300.13 MHz, CDCl3): d 8.74–
8.59 (m, 17H, ArH), 7.71 (m, 5H, ArH), 7.39 (m, 5H, ArH), 2.57 (s,
15H, CH3), 2.30 (s, 12H, CH3). 13C NMR (75.47 MHz, CDCl3): d
171.69 and 171.11 (triazine C), 145.52, 138.37, 136.27, 135.65,
135.26, 132.77, 130.93, 130.47, 130.12, 129.53, 127.79 and 126.56
(Ar), 29.70, 23.14 and 20.06 (CH3).
Acknowledgements
This investigation was supported by the General Secretariat of
Research and Technology of Greece and by the Université de
Montréal.
References and notes
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2,4,6-Tris(4-diphenylphosphinyl-3-methyl-phenylene)-1,3,5-triazine
(9): A solution of potassium diphenylphosphide in THF (0.5 M, 7 mL,
3.50 mmol) was added to
a white suspension of 2 (0.59 g,
1.00 mmol) in THF (15 mL) at room temperature under argon, and
then heated at reflux for 48 h. The reaction mixture was cooled to
room temperature, diluted by the addition of dichloromethane
(60 mL), washed with 10% aqueous NaOH (2 ꢀ 20 mL), then with
brine and dried over Na2SO4. The volatiles were evaporated and
the residue was evacuated at 180 °C. The remaining very viscous
oil turned to a solid on addition of ether/hexane (1:1, 10 mL), and
the solid was removed by filtration, washed with ether/hexane
and dried under vacuum at 180 °C. The solid was mixed with ace-
tone (50 mL) and 30% hydrogen peroxide (9 mL, 88.15 mmol) and
refluxed for 1 h in air. After cooling to room temperature, the vola-
tiles were evaporated under reduced pressure, the residue was dis-
solved in a minimum amount of dichloromethane, and slow
diffusion of ether afforded a solid which was then washed twice
with ether/dichloromethane (10:1) and then with ether yielding 9
(0.67 g, 70% based on 2).17 1H NMR (300.13 MHz, CDCl3): d 8.57–
8.46 (m, 6H, ArH), 7.67–7.19 (m, 33H, ArH), 2.58 (s, 9H, CH3). 13C
NMR (75.47 MHz, CDCl3): d 171.27 (triazine C), 144.00–125.56
(Ar), 21.88 (CH3). 31P NMR (121.50 MHz, CDCl3): d 31.84 (s). Anal.
Calcd for C60H48N3O3P3: C, 75.70; H, 5.08; N, 4.41. Found: C,
75.92; H, 5.03; N, 4.67.
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17. The mp apparatus used has an upper limit of 200 °C. Compounds 2–5 and 7–9
did not melt below 200 °C.