Duong et al.
JOCArticle
can accomplish their tasks independently and can thereby
control association without mutual interference. Future
studies will examine how metal complexes of compounds
4a-9a can be formed and used to construct complex
three-dimensional hydrogen-bonded networks. As a result,
the present work is a promising starting point for a wide
range of projects in organic and inorganic chemistry that
target the design and synthesis of related ligands for the self-
assembly of metal-organic materials with predetermined
structures.
making isomer 7b. Crystallization from CH2Cl2/MeCN pro-
vided red blocks: mp >250 °C (dec); IR (ATR) 2231 cm-1; 1H
NMR (400 MHz, CDCl3) δ 9.46 (dd, 2H, 3J=4.3 Hz, 4J=1.7
Hz), 8.77 (dd, 2H, 3J=8.3 Hz, 4J=1.7 Hz), 7.97 (dd, 2H, 3J=8.3
Hz, 3J=4.3 Hz); 13C NMR (100 MHz, CDCl3) δ 154.8, 147.0,
135.3, 126.0, 125.7, 117.1, 114.0; HRMS (ESI) calcd for
C14H6N4 þ H m/e 231.0665, found 231.0658.
Syntheses of DAT-Substituted Bipyridines 4a-6a and Phenan-
throlines 7a-9a. 6,60-(2,20-Bipyridine-5,50-diyl)bis(1,3,5-triazine-
2,4-diamine) (4a). A mixture of 2,20-bipyridine-4,40-dicarbonitrile
(4b; 0.673 g, 3.26 mmol),11 dicyandiamide (0.688 g, 8.18 mmol),
and KOH (0.202 g, 3.60 mmol) in 2-methoxyethanol (25 mL) was
heated at reflux for 12 h. The mixture was allowed to cool, and
precipitated solids were then separated by filtration, washed with
hot water, rinsed with MeOH, and dried under vacuum to
provide DAT-substituted bipyridine 4a (1.10 g, 2.94 mmol,
90%) as a nearly colorless solid: mp >350 °C; IR (ATR) 3459,
Experimental Section
General Notes. 2,20-Bipyridine-5,50-dicarbonitrile (4b),11 4,40-
dibromo-2,20-bipyridine (5c),20 2,20-bipyridine-6,60-dicarbonitrile
(6b),15 3,8-dibromo-1,10-phenanthroline (7c),21 4,7-dibromo-1,10-
phenanthroline (8c),22 and 5,6-dibromo-1,10-phenanthroline (9c)23
were prepared by methods reported previously. The syntheses of
dinitriles 5b and 7b-9b are described below, followed by the
preparation of DAT-substituted derivatives 4a-9a. Other chem-
icals were purchased from commercial sources and used without
further purification.
1
3327, 3153, 1662, 1633, 1525, 1442, 1394, 1359, 857 cm-1; H
NMR (400 MHz, DMSO-d6) δ 9.47 (d, 2H, 4J=2.0 Hz), 8.69 (dd,
2H, 3J=8.3 Hz, 4J=2.0 Hz), 8.58 (d, 2H, 3J=8.3 Hz), 6.929 (br s,
8H); 13C NMR (100 MHz, DMSO-d6) δ 169.4, 168.2, 157.4,
149.8, 137.2, 133.8, 121.5; HRMS (ESI) calcd for C16H14N12 þ H
m/e 375.1537, found 375.1547.
6,60-(2,20-Bipyridine-4,40-diyl)bis(1,3,5-triazine-2,4-diamine)
(5a). Compound 5a was prepared from 2,20-bipyridine-4,40-
dicarbonitrile (5b) in 85% yield by the method described above
for making analogue 4a: mp >350 °C; IR (ATR) 3463, 3317,
3119, 1643, 1531, 1396, 809 cm-1; 1H NMR (400 MHz, DMSO-
d6) δ 9.27 (s, 2H), 8.86 (d, 2H, 3J=4.9 Hz), 8.17 (dd, 2H, 3J=4.9
Hz), 7.02 (br d, 8H); 13C NMR (100 MHz, DMSO-d6) δ 169.5,
168.4, 156.6, 150.8, 146.7, 122.9, 119.5; HRMS (ESI) calcd for
C16H14N12 þ H m/e 375.1537, found 375.1538.
Syntheses of Dinitriles 5b and 7b-9b. 2,20-Bipyridine-4,40-
dicarbonitrile (5b)13-15. A stirred mixture of 4,40-dibromo-2,20-
bipyridine (5c; 0.873 g, 2.78 mmol),20 NaCN (0.274 g, 5.59 mmol),
Pd(OAc)2 (0.031 g, 0.14 mmol), 1,5-bis(diphenylphosphino)-
pentane (0.247 g, 0.561 mmol), TMEDA (0.488 g, 4.20 mmol),
and mesitylene (15 mL) was sparged with N2 for 10 min and then
was heated at reflux under N2 for 12 h. The mixture was allowed
to cool, degassed water was added, and the resulting slurry was
stirred for 10 min. The slurry was filtered, and the solid was
rinsed with pentane and then purified by flash chromatography
(silica gel, hexane/ethyl acetate 7/3) to give 2,20-bipyridine-4,40-
dicarbonitrile (5b; 0.363 g, 1.76 mmol, 63%) as a colorless solid:
mp 220 °C; IR (ATR) 2238 cm-1; 1H NMR (400 MHz, CDCl3) δ
8.90 (dd, 2H, 5J=0.87 Hz, 3J=4.9 Hz), 8.74 (dd, 2H, 4J=1.5
6,60-(2,20-Bipyridine-6,60-diyl)bis(1,3,5-triazine-2,4-diamine)
(6a). Compound 6a was prepared from 2,20-bipyridine-6,60-
dicarbonitrile (6b)15 in 90% yield by the method described above
for making analogue 4a: mp >350 °C; IR (ATR) 3479, 3357,
3146, 1617, 1538, 1403, 805 cm-1; 1H NMR (400 MHz, DMSO-
3
3
d6) δ 8.55 (d, 2H, J=7.8 Hz), 8.23 (d, 2H, J=7.6 Hz), 8.11
Hz, 5J=0.93 Hz), 7.62 (dd, 2H, 3J=4.9 Hz, 4J=1.5 Hz); 13
C
(t, 2H, J = 7.8 Hz), 6.92 (br d, 8H). 13C NMR (100 MHz,
3
NMR (100 MHz, CDCl3) δ 155.9, 150.7, 126.3, 123.5, 122.2,
116.8; HRMS (ESI) calcd for C12H6N4 þ H m/e 207.06652,
found 207.06687.
DMSO-d6) δ 171.3, 168.5, 155.8, 155.7, 138.6, 124.6, 123.1;
HRMS (ESI) calcd for C16H14N12 þ H m/e 375.1537, found
375.1537.
6,60-(1,10-Phenanthroline-3,8-diyl)bis(1,3,5-triazine-2,4-dia-
mine) (7a). Compound 7a was prepared from 1,10-phenanthro-
line-3,8-dicarbonitrile (7b) in 89% yield by the method de-
scribed above for making analogue 4a: mp >350 °C; IR
1,10-Phenanthroline-3,8-dicarbonitrile (7b). A stirred mixture
of 3,8-dibromo-1,10-phenanthroline (7c; 1.10 g, 3.25 mmol),21
NaCN (0.322 g, 6.57 mmol), Pd(OAc)2 (0.036 g, 0.16 mmol),
1,5-bis(diphenylphosphino)pentane (0.291 g, 0.661 mmol),
TMEDA (0.572 g, 4.92 mmol), and mesitylene (15 mL) was
sparged with N2 for 10 min and then was heated at reflux under N2
for 12 h. The mixture was allowed to cool, degassed water was
added, and the resulting slurry was stirred for 10 min. The slurry
was filtered, and the solid was rinsed with pentane and then purified
by flash chromatography (silica gel, hexane/ethyl acetate 1/1) to
give 1,10-phenanthroline-3,8-dicarbonitrile (7b; 0.460 g, 2.00 mmol,
62%) as a yellow-orange solid: mp >250 °C dec; IR (ATR) 2230
cm-1;1HNMR(400MHz, CDCl3) δ9.44 (d, 2H, 4J=2.0 Hz), 8.71
(d, 2H, 4J=2.0 Hz), 8.03 (s, 2H); 13C NMR (100 MHz, CDCl3) δ
151.3, 146.6, 140.9, 128.5, 127.9, 116.3, 110.1; HRMS (ESI) calcd
for C14H6N4 þ H m/e 231.0665, found 231.0662.
(ATR) 3325, 3165, 1634, 1531, 1391 cm-1 1H NMR (400
;
MHz, DMSO-d6) δ 9.88 (s, 2H), 9.20 (s, 2H), 8.18 (s, 2H),
7.01 (br s, 8H); 13C NMR (100 MHz, DMSO-d6) δ 169.1, 167.8,
149.7, 147.0, 135.9, 132.3, 128.9, 128.2; HRMS (ESI) calcd for
C18H14N12 þ H m/e 399.1537, found 399.1537.
6,60-(1,10-Phenanthroline-4,7-diyl)bis(1,3,5-triazine-2,4-diamine)
(8a). Compound 8a was prepared from 1,10-phenanthroline-
4,7-dicarbonitrile (8b) in 85% yield by the method described
above for making analogue 4a: mp >350 °C; IR (ATR) 3330,
3150, 1532 cm-1; 1H NMR (400 MHz, DMSO-d6) δ 9.20 (d, 2H,
3J=4.4 Hz), 8.66 (s, 2H), 8.03 (d, 2H, 3J=4.4 Hz), 7.03 (br s,
8H); 13C NMR (400 MHz, DMSO-d6) δ 172.4, 167.9, 150.4,
147.0, 144.3, 126.0, 125.5, 123.8; HRMS (ESI) calcd for
C18H14N12 þ H m/e 399.1537, found 399.1543.
1,10-Phenanthroline-4,7-dicarbonitrile (8b).18 Compound 8b
was prepared in 60% yield by the method described above for
making isomer 7b. Crystallization from CHCl3/MeCN provided
yellow blocks: mp >250 °C dec; IR (ATR) 2105 cm-1; 1H NMR
(400 MHz, CDCl3) δ 9.43 (d, 2H, 3J=4.4 Hz), 8.46 (s, 2H), 8.08
6,60-(1,10-Phenanthroline-5,6-diyl)bis(1,3,5-triazine-2,4-diamine)
(9a). Compound 9a was prepared from 1,10-phenanthroline-
5,6-dicarbonitrile (9b) in 20% yield by the method described
above for making analogue 4a: mp >350 °C; IR (ATR) 3120,
3
(d, 2H, J = 4.4 Hz); 13C NMR (100 MHz, CDCl3) δ 151.2,
1629, 1540 cm-1
(d, 2H, J = 3.0 Hz), 8.36 (d, 2H, J = 8.3 Hz), 7.75 (dd, 2H,
3J=3.0 Hz, 3J=8.0 Hz), 6.66 (br s, 8H); 13C NMR (100 MHz,
DMSO-d6) δ 172.7, 167.5, 150.9, 146.0, 136.0, 134.0, 127.1,
;
1H NMR (400 MHz, DMSO-d6) δ 9.12
146.4, 127.8, 127.4, 126.3, 119.8, 115.4; HRMS (ESI) calcd for
C14H6N4 þ H m/e 231.0665, found 231.0677.
3
3
1,10-Phenanthroline-5,6-dicarbonitrile (9b). Compound 9b
was prepared in 52% yield by the method described above for
1340 J. Org. Chem. Vol. 76, No. 5, 2011