1
8
monitored by TLC or NMR and in most cases were completed
within a few minutes. The reaction was terminated by pouring
it into NaHCO3 solution followed by water until neutral,
1,7-Phenanthrolin-8-one (15) was prepared from 1,7-phe-
nanthroline (13) (0.6 g, 3.3 mmol) as described above, using 2
equiv of the oxidizing solution. After hydrolysis, a beige product
(0.58 g, 90% yield) was obtained: mp > 300 °C (decomposition);
drying the organic layer over MgSO and evaporation of the
4
1
solvent. The crude product was usually purified by vacuum
flash chromatography (Merck silica gel 60H) with petroleum
ether/ethyl acetate serving as eluent or by recrystallization.
Several of the products are known and referenced, but frequently
not adequately described. In such cases their properties are given
below.
H NMR (DMSO-d ) 8.98–8.96 (2 H, m), 8.39 (1 H, dd, J =
8.0, J = 1.6 Hz), 8.07 (1 H, d, J = 8.9 Hz), 7.58–7.54 (2 H,
m), 6.68 ppm (1 H, d, J = 9.7 Hz); C NMR (DMSO-d6)
162.34, 150.81, 144.28, 140.26, 136.59, 135.84, 130.84, 123.27,
121.47, 120.72, 116.99, 113.99 ppm; HRMS (ESI) m/z calcd for
C H N O 197.0715 (M + H) , found 197.0719.
4,7-Phenanthroline-3,8(4H,7H)-dione (18) was prepared
from 4,7-phenanthroline (16) (0.6 g, 3.3 mmol) as described
above, using 5 equiv of the oxidizing solution. A beige
product (0.67 g, 95% yield) was obtained: mp > 300 °C
6
1
2
1
13
1
+
12 8 2
1
5
2
-Pyridyl-6-acetoxypyridine (2) was prepared from 2,2′-
bipyridine (1) (0.4 g, 2.6 mmol) as described above, using 2.5
equiv of the oxidizing solution. A white solid (0.46 g, 85%
1
yield) was obtained: mp 73–74 °C; H NMR (CDCl ) 8.68–8.66
3
1
(1 H, m), 8.35–8.32 (2 H, m), 7.92 (1 H, t, J = 7.9 Hz), 7.80 (1
(decomposition); H NMR (DMSO-d ) 8.54 (2 H, d, J = 9.6
Hz), 7.50 (2 H, s), 6.64 ppm (2 H, d, J = 9.6 Hz); C NMR
6
1
13
H, td, J = 7.7, J = 1.8 Hz), 7.31 (1 H, ddd, J = 7.5, J = 4.8,
1
2
1
2
1
J = 1.1 Hz), 7.10 (1 H, dd, J = 8.0, J = 0.7 Hz), 2.39 ppm (3
(DMSO-d6) 161.26, 135.05, 134.72, 122.90, 119.07,
114.08 ppm; HRMS (ESI) m/z calcd for C H N O 213.0664
3
1
2
13
H, s); C NMR (CDCl ) 169.26, 157.44, 155.82, 155.13,
3
12
8
2
2
+
1
2
49.38, 140.44, 137.09, 124.19, 121.58, 119.36, 116.45,
(M + H) , found 213.0667.
+
19
1.51 ppm; MS (CI) m/z 215.1 (M + H) .
6,6-(Pyridine-2,6-diyl)dipyridin-2(1H)-one (21) was pre-
pared from 2,2′:6′,2′′-terpyridine (19) (0.5 g, 2.1 mmol) as
described above, using 10 equiv of the oxidizing solution. After
hydrolysis, a white product (0.48 g, 85% yield) was obtained
with physical properties matching those in the literature.
1
6
6
,6′-Diacetoxy-2,2′-bipyridine (3) was prepared from 2,2′-
bipyridine (1) (0.4 g, 2.6 mmol) as described above, using 5
equiv of the oxidizing solution. A white solid (0.62 g, 90%
yield) was obtained with physical constants in accordance to the
ones in the literature.
6,6′′-Diacetoxy-4′-(4-chlorophenyl)-2,2′:6′,2′′-terpyridine
(23) was prepared from 22 (0.4 g, 1.2 mmol) as described above,
using 10 equiv of the oxidizing solution. A beige product
6
,6′-Diacetoxy-5,5′-dimethyl-2,2′-bipyridine (5) was pre-
pared from 5,5′-dimethyl-2,2′-bipyridyl (4) (0.7 g, 3.8 mmol) as
described above, using 5 equiv of the oxidizing solution. A pale
yellow product (1.08 g, 95% yield) was obtained, mp starting to
1
(0.42 g, 80% yield) was obtained: mp 177–179 °C; H NMR
(CDCl ) 8.59–8.57 (4 H, m), 7.98 (2 H, t, J = 8.0 Hz), 7.79 (2
3
1
1
decompose at 210 °C; H NMR (CDCl ) 8.17 (2 H, d, J = 7.8
H, d, J = 8.5 Hz), 7.49 (2 H, d, J = 8.5 Hz), 7.15 (2 H, d, J =
1 1 1
3
1
13
Hz), 7.68 (2 H, d, J = 7.8 Hz), 2.39 (3 H, s), 2.24 ppm (3 H, s);
8.0), 2.4 ppm (3 H, s); C NMR (CDCl ) 169.30, 157.45,
1
3
1
3
C NMR (CDCl ) 168.95, 156.19, 152.43, 141.50, 125.68,
155.64, 155.14, 149.46, 140.42, 136.94, 135.43, 129.30, 128.84,
3
1
19.93, 21.13, 16.04 ppm; HRMS (ESI) m/z calcd for
119.70, 119.45, 116.77, 29.84 ppm; HRMS (APPI) m/z calcd for
C H N O Cl 460.1064 (M + H) , found 460.1059.
25 18 3 4
+
C H N O 323.1008 (M + Na), found 323.1010. Anal. Calcd.
1
6
16
2
4
for C H N O : C, 63.99; H, 5.37; N, 9.33. Found: C, 63.69;
1
6 16 2 4
H, 5.16; N, 9.22.
,2′-Diacetoxy-4,4′-bipyridyline(7) was prepared from 4,4′-
bipyridine (6) (0.5 g, 3.2 mmol) as described above, using 5
2
Acknowledgements
This work was supported by the USA-Israel Binational Science
Foundation (BSF), and by the Israel Science Foundation. We
wish to express our gratitude to Prof. Y. Kashman from our
school for his help with the NOE experiments. Y. H. thanks the
Israel Ministry of Science and Technology for a scholarship.
equiv of the oxidizing solution. A pale beige product (0.82 g,
1
9
5% yield) was obtained: mp 178–181 °C; H NMR (CDCl )
3
8
.28 (2 H, d, J = 7.7 Hz), 7.90 (2 H, t, J = 7.8 Hz), 7.11 (2 H,
1
1
1
3
d, J = 8.0 Hz), 2.40 ppm (3 H, s); C NMR (CDCl ) 169.20,
1
3
1
57.39, 154.53, 140.47, 119.68, 116.85, 21.48 ppm; HRMS
(
APPI) m/z calcd for C H N O 295.0695 (M + Na), found
1
4 12 2 4
2
1
95.0696. Anal. Calcd. for C H N O : C, 61.76; H, 4.44; N,
14 12 2 4
References
0.29. Found: C, 61.46; H, 4.30; N, 10.36.
,7-Dimethyl-1,10-phenanthrolin-2(1H)-one (12) was pre-
pared from 5,6-dimethyl-1,10-phenanthroline (10) (0.4 g,
.9 mmol) as described above, using 2 equiv of the oxidizing
solution. After hydrolysis, a pale beige product (0.38 g, 90%
4
1
(a) N. Armaroli, Chem. Soc. Rev., 2001, 30, 113; (b) D. R. McMillin and
K. M. McNett, Chem. Rev., 1998, 98, 1201.
2
M. K. Nazeeruddin and M. Grätzel, in Photofunctional Transition Metals
Complexes, Structure and Bonding, ed. V. W. W. Yam, Springer-Verlag,
Berlin, 2007.
1
1
yield) was obtained: mp 202–203 °C; H NMR (CDCl ) 10.73
3
3 K. Szacilowski, W. Macyk, A. Drzewiecka-Matuszek, M. Brindell and
(
7
1 H, br), 8.75 (1 H, d, J = 4.3 Hz), 7.73 (2 H, q, J = 9.3 Hz),
G. Stochel, Chem. Rev., 2005, 105, 2647.
1
1
4
E. Baranoff, F. Barigelletti, S. Bonnet, J. P. Collin, L. Flamigni,
P. Mobian and J. P. Sauvage, in Photofunctional Transition Metals Com-
plexes, Structure and Bonding, ed. V. W. W. Yam, Springer-Verlag,
Berlin, 2007.
5 (a) K. E. Erkkila, D. T. Odom and J. K. Barton, Chem. Rev., 1999, 99,
2777; (b) C. Metcalfe and J. A. Thomas, Chem. Soc. Rev., 2003, 32, 215.
K. K. W. Lo, K. H. K. Tsang, K. S. Sze, C. K. Chung, T. K. M. Lee,
K. Y. Zhang, W. K. Hui, C. K. Li, J. S. Y. Lau, D. C. M. Ng and N. Zhu,
Coord. Chem. Rev., 2007, 251, 2292.
.38 (1 H, d, J = 4.3 Hz), 6.70 (1 H, s), 2.74 (3 H, s), 2.58 ppm
1
13
(3 H, s); C NMR (CDCl ) 161.91, 149.00, 148.74, 144.79,
3
1
1
2
36.55, 135.44, 128.05, 123.97, 122.47, 121.84, 117.80, 116.93,
9.40, 18.91 ppm; HRMS (APPI) m/z calcd for C H N O
1
4 12 2
+
25.1028 (M + H) , found 225.1031. Anal. Calcd. for
6
C H N O: C, 74.98; H, 5.39; N, 12.49. Found: C, 74.68; H,
5
1
4 12 2
.34; N, 12.28.
This journal is © The Royal Society of Chemistry 2012
Org. Biomol. Chem., 2012, 10, 1856–1860 | 1859