9510 J . Org. Chem., Vol. 61, No. 26, 1996
Dabdoub et al.
mixture was stirred for 1.5 h, and after workup, the product
7b was recrystallized from hexane: yield 0.398 g (82%); MS
m/z 488 (23.42) C18H15TeI, 231 (85.29), 215 (100.00); 80 MHz
1H NMR (CDCl3) δ 2.35 (s, 6H), 7.05 (d, J ) 8 Hz, 2H), 7.12
(d, J ) 8 Hz, 2H), 7.28 (d, J ) 8 Hz, 2H), 7.36 (d, J ) 8 Hz,
2H), 7.78 (s, 1H); 13C NMR (CDCl3) δ 21.2, 21.3, 87.2, 126.5,
128.9, 129.1, 129.7, 135.9, 137.9, 138.2, 141.6, 149.8. Anal.
Calcd for C18H15TeI : C, 44.50; H, 3.11. Found: C, 44.62; H,
3.14.
treatment with NaBH4 and workup as described above, the
residue was distilled in a Kugelrohr apparatus. The compound
7e was distilled at 105 °C/0.1 mmHg, followed by 7g (140 °C/
0.1 mmHg): yield of 7g 0.017 g (4%); MS m/z 434 (75.84) C4H2-
TeI2, 307 (50.18), 127 (100.00); 80 MHz 1H NMR (CDCl3) δ
7.52 (d, J ) 7.1 Hz, 1H), 8.87 (d, J ) 7.1 Hz, 1H).
2-P h en yl-3-iod otellu r op h en e Diiod id e (9a ). To a one-
neck round-bottomed flask containing a solution of (Z)-1-
(butyltelluro)-4-phenylbut-1-en-3-yne (5f) (0.311 g, 1.0 mmol)
in petroleum ether (10 mL) at room temperature was added
iodine (0.507 g, 2.0 mmol) in one portion. The reaction mixture
was stirred at this temperature for 4 h, extracted with ethyl
acetate, and washed with a saturated solution of sodium
thiosulfate (4 × 60 mL). After the organic phase (MgSO4) was
dried, the solvents were removed under reduced pressure and
the residue was recrystallized from carbon tetrachloride to give
the pure compound 9a as highly insoluble yellow-brown
crystals 0.283 g (45%): mp ) 108-109 °C; MS m/z 638 (0.00),
256 (7.1), 64 (100.00); 60 MHz 1H NMR (THF-d6) δ 7.0-7.5
(m, 5H), 7.76 (d, J ) 7 Hz, 1H), 8.77 (d, J ) 7 Hz, 1H). Anal.
Calcd for C10H7TeI3: C, 18.82; H, 1.11. Found: C, 18.43; H,
0.97.
2,5-Bis(p-m eth oxyph en yl)-3-iodotellu r oph en e (7c). The
same procedure was followed as for 7a , using the 2,4-bis(p-
methoxyphenyl)but-1-en-3-yne 5c (0.447 g, 1.0 mmol). The
mixture was stirred for 2 h, and after workup, the product
was recrystallized from hexane. Yield: 0.414 g, (80%). MS
1
m/z 520 (29.19) C18H15O2TeI, 263 (100.00); 80 MHz H NMR
(CDCl3) δ 3.79 (s, 3H), 3.81 (s, 3H), 6.82 (d, J ) 8 Hz, 2H),
6.88 (d, J ) 8 Hz, 2H), 7.32 (d, J ) 8 Hz, 2H), 7.43 (d, J ) 8
Hz, 2H), 7.72 (s, 1H); 13C NMR (CDCl3) δ 55.2, 55.3, 87.2, 113.8,
114.4, 127.6, 130.3, 131.5, 133.1, 140.7, 141.1, 149.2, 159.3,
159.7. Anal. Calcd for C18H15OTeI : C, 41.75; H, 2.92.
Found: C, 41.97; H, 2.88.
2,5-Dim eth yl-3-iod otellu r op h en e (7d ). The same pro-
cedure was followed as for 7a , using the 2,4-dimethylbut-1-
en-3-yne 5d (0.263 g, 1.0 mmol). The mixture was stirred for
3 h, and after workup, the residue was purified by flash
chromatography on silica gel with hexane as the mobile phase.
After evaporation of hexane, 7d was obtained as a yellow oil:
yield 0.301 g (90%); CG/MS m/z 336 (21.44) C6H7TeI, 209
Bis(1,4-d ip h en ylbu t-1-en -3-yn yl) d itellu r id e 14. To a
two-neck round-bottomed flask, under N2, containing a solu-
tion of 7a (0.458 g, 1.0 mmol) in THF (10 mL) at -78 °C was
added n-BuLi (0.3 mL, 0.75 mmol, 2.5 M) in one portion. The
initial yellow solution turned dark red. The reaction mixture
was stirred for 10 min, and then water (2.0 mL) was added.
The reaction mixture was diluted with ethyl acetate (∼40 mL)
and washed with brine (3 × 50 mL). The organic phase was
dried over MgSO4 and filtered. The solvent was removed
under reduced pressure, and the dark red residue was purified
by flash chromatography to give compound 14 as identified
by 1H NMR spectroscopy. Compound 14 is unstable, and
elemental analysis was not possible: 0.178 g (54%); MS m/z
666 (M + 4) (0.00), 536 (6.34) C32H22Te, 406 (36.09), 329
1
(17.60), 77 (100.00); 80 MHz H NMR (CDCl3) δ 2.38 (s, 3H),
2.53 (d, J ≈ 1 Hz, 3H), 7.02 (q, J ≈ 1 Hz, 1H); 13C NMR (CDCl3)
δ 21.6, 25.7, 87.8, 135.0, 140.9, 142.5. Anal. Calcd for C6H7-
TeI: C, 21.60; H, 2.11. Found: C, 21.62; H, 1.98.
3-Iod otellu r op h en e (7e). The same procedure was fol-
lowed as for 7a , using the (Z)-1-(butyltelluro)but-1-en-3-yne
(5e) (0.235g, 1.0 mmol). The reaction mixture was stirred for
1 h, and the product was extracted with petroleum ether (3 ×
40 mL) and washed with brine (3 × 40 mL). The solid residue
(compound 12) was separated and treated as described below.
After evaporation of the petroleum ether layer, the 3-iodotel-
lurophene (7e) was obtained as yellow crystals: mp ) 37-
37.5 °C; yield 0.123 g (40%); CG/MS m/z 308 (100.00) C4H3TeI,
181 (50.44), 51 (41.12); 80 MHz 1H NMR (CDCl3) δ 7.72 (dd, J
) 7 Hz, J ≈ 1.5 Hz, 1H), 8.60 (dd, J ) 7 Hz, J ≈ 2 Hz, 1H),
8.98 (dd, J ≈ 2 Hz, J ≈ 1.5 Hz, 1H); 13C NMR (CDCl3) δ 85.3,
126.7, 128.2, 145.3. Anal. Calcd for C4H3TeI: C, 15.72; H,
0.99. Found: C, 15.75; H, 0.95.
1
(15.45), 202 (100.00); 60 MHz H NMR (CDCl3) δ 6.1 (s, 2H),
7.1-7.7 (m, 20H).
2,5-Dip h en yl-3-iod otellu r op h en e (7a ) by Rea ction of
14 w ith I2. To a one-neck round-bottomed flask containing a
solution of 14 (0.331 g; 0.5 mmol) in petroleum ether (10 mL)
at room temperature was added I2 (0.254 g; 1.0 mmol) in one
portion. The reaction mixture was stirred at this temperature
for 1 h, poured into an Erlenmeyer flask (250 mL), and diluted
with ethyl acetate (40 mL), and water (40 mL) was added to
the organics. Under vigorous stirring, solid NaBH4 was added
in small portions until the dark brown color turned pale yellow
(gas evolution is observed). The organic phase was separated
and washed with water (4 × 50 mL). After the organic phase
was dried over anhydrous MgSO4, the solvents were removed
under reduced pressure. Recrystallization of hexanes gave the
pure 3-iodotellurophene (7a ) as yellow crystals. Yield: 0.229
g (50%). Physical properties and spectral data are similar to
those of compound 7a obtained by reaction of 5a with iodine.
Bis(1,4-d ip h en ylbu t-1-en -3-yn yl) Tellu r id e (16). To a
two-neck round-bottomed flask under deoxygenated nitrogen,
containing a solution of 7a (0.458 g, 1.0 mmol) in THF (10
mL), was added n-BuLi (0.8 mL, 2.0 mmol, 2.5 M) dropwise
(over 3 min). During the addition the initial yellow solution
turned red. After the end of addition (3 min) the reaction
mixture was stirred for 30 min (the solution turned yellow
again), and then water (2.0 mL) was added under N2. The
reaction mixture was diluted with ethyl acetate (∼40 mL) and
washed with brine (3 × 50 mL). The organic phase was dried
over MgSO4 and filtered. The solvent was removed under
reduced pressure, and the yellow solid formed was washed
with hexane. The solid was purified by recrystallization from
hexane to obtain the pure compound 16: 0.363 g (68%); mp )
169-170 °C; MS m/z 536 (9.03) C32H22Te, 406 (56.36), 329
(21.46), 202 (100.00); 200 MHz 1H NMR (CDCl3) δ 6.28 (s, 2H),
7.07 (s,10H), 7.2-7.4 (m, 6H), 7.5-7.7 (m, 4H); 13C NMR
(CDCl3) δ 90.8, 117.1, 123.2, 127.6, 127.8, 128.4, 129.6, 131.5,
140.2, 142.0. Anal. Calcd for C32H22Te: C, 71.96; H, 4.15.
Found: C, 71.56; H, 4.0.
1-(Bu tyltellu r o)-3,4-d iiod o-1,3-bu ta d ien e (13). To the
brown solid residue (containing compound 12) obtained above
that is insoluble in petroleum ether were added tetrahydro-
furan (40 mL) and water (30 mL). Under vigorous stirring,
solid NaBH4 was added in small portions until the dark brown
organic phase turned pale yellow (gas evolution is observed).
The organic phase was separated and washed with water (3
× 30 mL). After the organic phase was dried over anhydrous
MgSO4, the solvent was removed under reduced pressure. The
1H NMR spectrum of the liquid residue showed that a mixture
1
of 7e and 13 in a 1:2 ratio was present: 60 MHz H NMR of
13 (CDCl3) δ 0.93 (t, J ) 7 Hz, 3H), 2.0-3.0 (m, 4H), 2.68 (t,
J ) 7 Hz, 2H), 6.75 (d, J ) 11 Hz, 1H), 7.01 (s, 1H), 7.19 (d,
J ) 11 Hz, 1H). Attempts to separate 13 by distillation failed
since at 84 °C/0.01 mmHg 13 decomposes losing iodine to give
compound 5e.
2-P h en yl-3-iod otellu r op h en e (7f). The same procedure
was followed as for 7a , using the (Z)-1-(butyltelluro)-4-phen-
ylbut-1-en-3-yne (5f) (0.311 g, 1.0 mmol). The mixture was
stirred for 4 h, and after workup, the residue was purified by
flash chromatography on silica gel with hexane as mobile
phase. After evaporation of hexane 7f was obtained as a
yellow oil: yield 0.305 g (80%); MS m/z 384 (0.00) 256 (7.23),
1
64 (100.00); 80 MHz H NMR (CDCl3) δ 7.2-7.6 (m, 5H), 7.87
(d, J ) 7 Hz, 1H), 8.69 (d, J ) 7 Hz, 1H); 13C NMR (CDCl3) δ
127.9, 128.3, 129.1, 147.0. Anal. Calcd for C10H7TeI: C, 31.47;
H, 1.85. Found: C, 31.28; H, 1.93.
2,3-Diiod otellu r op h en e (7g). The same procedure was
followed as for 7e, except that 0.762 g (3.0 mmol) of iodine
was used and the reaction mixture was stirred for 4 h. After
(E)-1,4-Dip h en yl-1-bu ten -3-yn e (20) by Rea ction of 16
w ith n -Bu Li. To a solution of 16 (0.267 g, 0.5 mmol) in THF