PRACTICAL SYNTHETIC PROCEDURES
1,4-Diiodo-2,5-bis(halomethyl)benzene
2973
ture was slowly poured into a sat. solution of NaS2O3 (20 mL) and
H2O (80 mL). The yellow liquid was decanted and the residue sus-
pended in MeOH (100 mL). The precipitate was isolated by filtra-
tion and washed with H2O and MeOH. The precipitate was dried
under vacuum to give 9.7 g (23%) of 5 as a pale brown solid, which
was used in the next step without further purification. An analytical
sample was obtained by recrystallization from CHCl3 as a white sol-
id; mp 202 °C.
solid. An analytical sample was obtained by recrystallization from
CHCl3; mp 221 °C.
1H NMR (250 MHz, C2D2Cl4): d = 7.91 (s, 2 H), 4.50 (s, 4 H).
13C NMR (100 MHz, C2D2Cl4): d = 141.9, 140.8, 99.7, 36.8.
MS (EI): m/z (%) = 515.5 (29) [M+].
Anal. Calcd for C8H6Br2I2: C, 18.63; H, 1.17. Found: C, 18.53; H,
1.80.
1H NMR (250 MHz, C2D2Cl4): d = 7.80 (s, 2 H), 5.04 (s, 4 H), 2.17
(s, 6 H).
Acknowledgment
13C NMR (100 MHz, CD2Cl2): d = 170.7, 140.7, 139.8, 97.9, 69.24,
21.2.
Financial support by the Volkswagen Stiftung is gratefully acknow-
ledged.
MS (EI): m/z (%) = 473.9 (11) [M+].
Anal. Calcd for C12H12I2O4: C, 30.40; H, 2.55. Found: C, 30.43; H,
3.26.
References
(1) New adress: Kekulé-Institut für Organische Chemie und
Biochemie der Universität Bonn, Gerhard-Domagk-Straße
1, 53121 Bonn, Germany.
2,5-Diiodo-1,4-bis(hydroxymethyl)benzene (6)
Diacteate 5 (9.0 g, 18.9 mmol) was suspended in MeOH (100 mL)
and an aq solution of NaOH (10%, 15 mL) was added. The mixture
was heated to reflux and stirred overnight. After cooling, the precip-
itate was collected by filtration and washed with MeOH. The pre-
cipitate was dried under vacuum to give 6.6 g (89%) of 6 as a white
solid, that was used in the next step without further purification. An
analytical sample was obtained by recrystallization from acetone;
mp 211–212 °C.
1H NMR (250 MHz, THF-d8): d = 7.91 (s, 2 H), 4.64 (t, J = 5.3 Hz,
2 H), 4.45 (d, J = 5.3 Hz, 4 H).
13C NMR (100 MHz, THF-d8): d = 145.6, 138.2, 96.6, 68.4.
MS (EI): m/z (%) = 398.9 (23%) [M+].
(2) Amjijs, C. H. M.; van Klink, G. P. M.; Lutz, M.; Spek, A. L.;
van Koten, G. Organometallics 2005, 24, 2944.
(3) (a) Rau, I. U.; Rehan, M. Makromol. Chem. 1993, 194,
2225. (b) Claussen, W.; Schulte, N.; Schlüter, A.-D.
Makromol. Chem., Rapid Commun. 1995, 16, 89.
(4) Kay, K.-Y.; Baek, Y. G.; Yeu, S. Y. Synthesis 1997, 35.
(5) McCoy, R. K.; Karasz, F. E.; Sarker, A.; Lahti, P. M. Chem.
Mater. 1991, 3, 941.
(6) (a) Wilson, J. N.; Hardcastle, K. I.; Josowict, M.; Bunz, U.
H. F. Tetrahedron 2004, 60, 7157. (b) Wilson, J. N.;
Windscheif, P. M.; Evans, U.; Myrick, M. L.; Bunz, U. H. F.
Macromolecules 2002, 35, 8681. (c) Bonifacio, M. C.;
Robertson, C. R.; Jung, J.-Y.; King, B. T. J. Org. Chem.
2005, 70, 8522.
Anal. Calcd for C8H8I2O2: C, 24.64; H, 2.07. Found: C, 24.64; H,
2.71.
(7) Cianga, I.; Yagci, Y. Eur. Polym. J. 2002, 38, 695.
(8) Fitton, P.; Rick, A. E. J. Organomet. Chem. 1971, 28, 287.
(9) Wheland, R. C.; Martin, E. L. J. Org. Chem. 1975, 40, 3101.
(10) See, for example: Bedard, T. C.; Moore, J. S. J. Am. Chem.
Soc. 1995, 117, 10662.
(11) The first synthesis of 1 (ref. 8; also prepared by radical side
chain bromination) does not report the product purity.
(12) (a) Wirth, H. O.; Königstein, O.; Kern, W. Justus Liebigs
Ann. Chem. 1960, 643, 84. (b) Merkushev, E. B. Synthesis
1988, 923.
(13) Appel, R. Angew. Chem., Int. Ed. Engl. 1975, 14, 801.
(14) Selected crystal data: 1 (T = 120 K): triclinic, P–1,
a = 4.3575 (4), b = 7.2917 (4), c = 8.9994 (5) Å, a = 70.8917
(13), b = 83.3779 (12), g = 84.9725 (12)°, V = 268.01 (3) Å3,
Z = 2, Dx = 2.645 gcm–3, 5890 independent reflections, 1567
reflections observed, R = 0.0357, Rw = 0.0406. 2 (T = 120
K): triclinic, P–1, a = 4.3865 (4), b = 7.4454 (4), c = 9.0972
(5) Å, a = 71.7302 (13), b = 83.6831 (12), g = 84.8666 (12)°,
V = 279.94 (3) Å3, Z = 1, Dx = 3.059 gcm–3, 5457
independent reflections, 1454 reflections observed,
R = 0.0313, Rw = 0.0345.
2,5-Diiodo-1,4-bis(chloromethyl)benzene (1)
Under an argon atmosphere, CCl4 (492 mg, 3.20 mmol) and Ph3P
(839 mg, 3.20 mmol) were added to a suspension of 6 (500 mg, 1.28
mmol) in THF (2 mL). The mixture was heated to 50 °C and stirred
overnight. After adding MeOH (5 mL), the white precipitate was
collected by filtration. Filtration of the crude product through a
short silica gel filled column (PE–CH2Cl2, 2:1) gave 330 mg (60%)
of 1 as a white solid; mp 171 °C; Rf 0.8.
1H NMR (250 MHz, CD2Cl2): d = 7.95 (s, 2 H), 4.61 (s, 4 H).
13C NMR (100 MHz, THF-d8): d = 143.5, 141.9, 100.1, 50.1.
MS (EI): m/z (%) = 425.8 (100) [M+].
Anal. Calcd for C8H6Cl2I2: C, 22.51; H, 1.42. Found: C, 22.73; H,
1.71.
2,5-Diiodo-1,4-bis(bromomethyl)benzene (2)
Under an argon atmosphere, CBr4 (2.12 g, 6.40 mmol) and PPh3
(1.68 g, 6.39 mmol) were added to a solution of 6 (1.0 g, 2.56 mmol)
in THF (20 mL). After stirring overnight, MeOH (10 mL) was add-
ed and the white precipitate was collected by filtration. The precip-
itate was dried under vacuum to give 1.07 g (81%) of 2 as a white
(15) Selected bond length for 1: I1–C2: 2.096 (3) Å; Cl1–C4:
1.804 (4) Å.
Synthesis 2006, No. 17, 2971–2973 © Thieme Stuttgart · New York