V. K. Fulwa, V. Manivannan / Tetrahedron Letters 53 (2012) 2420–2423
2423
+
+
Chem. 2001, 66, 2862–2864; (f) Bluhm, M. E.; Ciesielski, M.; Görls, H.; Döring,
215 °C; ESI-Mass: calcd for
C
24
H
3
16
N
8
416.150 found (M +H) 417.17.
M. Angew. Chem., Int. Ed. 2002, 41, 2962–2965; (g) Wang, J.; Mason, R.;
VanDerveer, D.; Feng, K.; Bu, X. R. J. Org. Chem. 2003, 68, 5415–5418; (h) Wang,
J., ; Dyers, L., Jr.; Mason, R., Jr.; Amoyaw, P.; Bu, X. R. J. Org. Chem. 2005, 70,
400 MHz 1H NMR (d (J, Hz), CDCl
): 9.06 (1H, s), 8.93 (1H, s), 8.82 (1H, d,
4.0), 8.71 (1H, d, 6.8), 8.62 (1H, d, 6.4), 8.30 (3H, m), 8.10 (1H, d, 7.6), 7.84 (1H, t,
7.6), 7.54 (1H, d, 9.2), 7.49 (1H, t, 4.8), 7.37 (2H, m), 6.95 (1H, t, 6.4), 6.80 (1H, t,
2
353–2356; (i) Kim, D.; Wang, L.; Hale, J. J.; Lynch, C. L.; Budhu, R. J.; MacCoss,
6.4). 100 MHz 13C NMR (d, CDCl
3
): 151.0, 150.3, 150.2, 149.4, 149.3, 148.7,
M.; Mills, S. G.; Malkowitz, L.; Gould, S. L.; DeMartino, J. A.; Springer, M. S.;
Hazuda, D.; Miller, M.; Kessler, J.; Hrin, R. C.; Carver, G.; Carella, A.; Henry, K.;
Lineberger, J.; Schleif, W. A.; Emini, E. A. Bioorg. Med. Chem. Lett. 2005, 15, 2129–
147.5, 146.7, 136.9, 136.5, 135.8, 126.5, 126.0, 125.6, 124.9, 124.3, 124.2, 124.1,
123.3, 122.4, 122.2, 121.4, 117.6, 115.2. Selected FT-IR (KBr, cm ): 1636, 1580,
1557, 1523, 1510, 1465, 1424, 1363, 1306, 1224, 1146, 977, 945, 808, 743, 702,
À1
2
5
134; (j) Shibahara, F.; Kitagawa, A.; Yamaguchi, E.; Murai, T. Org. Lett. 2006, 8,
621–5624; (k) Shibahara, F.; Sugiura, R.; Yamaguchi, E.; Kitagawa, A.; Murai,
692. Anal. calcd for C24
3.74; N, 26.76. 1-((3-pyridyl)methanimine)-3-(3-pyridyl)imidazo[1,5-a]pyridine
16 8
H N : C, 69.22; H, 3.87; N, 26.91. Found: C, 68.96; H,
+
T. J. Org. Chem. 2009, 74, 3566–3568; (l) Crawforth, J. M.; Paoletti, M.
Tetrahedron Lett. 2009, 50, 4916–4918; (m) Shibahara, F.; Yamaguchi, E.;
Kitagawa, A.; Imai, A.; Murai, T. Tetrahedron 2009, 65, 5062–5073; (n) Tahara,
S.; Shibahara, F.; Maruyama, T.; Murai, T. Chem. Commun. 2009, 7009–7011; (o)
Arvapalli, V. S.; Chen, G.; Kosarev, S.; Tan, M. E.; Xie, D.; Yet, L. Tetrahedron Lett.
(3b): Yield: 130 mg (15%). mp 190 °C; ESI-Mass: calcd for C18
H
N
13 5
300 found
= 0.25 (3:7 ethylacetate/hexane). 104 MHz H NMR (d (J, Hz),
): 9.33 (1H, s), 9.12 (2H, s), 8.70 (1H, d, 7.0), 8.64 (1H, d, 7.0), 8.34 (1H, d,
8.0), 8.20 (2H, m), 8.03 (1H, d, 9.6), 7.50 (1H, t, 8.0), 7.40 (1H, t, 8.0), 7.02 (1H, t,
8.8), 6.70 (1H, t, 6.4). 100 MHz 13C NMR (d, CDCl
): 151.0, 150.9, 150.4, 149.9,
+
1
(M +H) 300.10. R
CDCl
f
3
3
2
2
010, 51, 284–286; (p) Zhang, A.; Zheng, X.; Fan, J.; Shen, W. Tetrahedron Lett.
010, 51, 828–831; (q) Niyomura, O.; Yamaguchi, Y.; Tamura, S.; Minoura, M.;
148.8, 135.7, 134.6, 124.0, 123.8, 121.3, 120.9, 118.9, 115.0. Selected FT-IR (KBr,
cm ): 1633, 1591, 1513, 1479, 1417, 1356, 1301, 1242, 1189, 1177, 1128,
À1
Okamoto, Y. Chem. Lett. 2011, 40, 449–451; (r) Huang, C.; Giokaris, A.;
Gevorgyan, V. Chem. Lett. 2011, 40, 1053–1054; (s) Yamaguchi, E.; Shibahara,
F.; Murai, T. Chem. Lett. 2011, 40, 939–940.
13 5
1026, 956, 824, 804, 747, 732, 713, 698. Anal. calcd for C18H N : C, 72.23; H,
4.38; N, 23.40. Found: C, 71.90; H, 4.28; N, 23.22. 1-(3-(2-pyridyl)-5-(4-pyridyl)-
1,2,4-triazolyl)-3-(4-pyridyl)imidazo[1,5-a]pyridine (4a): Yield: 500 mg (13%).
+
+
6
7
.
.
Fulwa, V. K.; Sahu, R.; Jena, H. S.; Manivannan, V. Tetrahedron Lett. 2009, 50,
mp 220 °C; ESI-Mass: calcd for C24
400 MHz H NMR (d (J, Hz), CDCl
3
H
16
N
8
416.150 found (M +H) 417.10.
): 8.81 (3H, m), 8.65 (2H, m), 8.47 (1H, d, 7.2),
8.29 (1H, d, 8.0), 7.86 (1H, t, 6.4), 7.73 (4H, m), 7.56 (1H, d, 9.2), 7.41 (1H, t, 5.2),
7.02 (1H, t, 9.2), 6.89 (1H, t, 7.2). 100 MHz 13C NMR (d, CDCl
): 152.0, 151.0,
1
6
264–6267.
A mixture of hydrazine hydrate (0.250 g, 5.0 mmol) and 2-cyanopyridine
1.04 g, 10.0 mmol) was heated at 100 °C in an oil-bath for 12 h. The mixture
(
3
was cooled and then 2-pyridinecarboxaldehyde (1.07 g, 10.0 mmol) was added
and reheated at 100 °C in an oil-bath for another 6 h. The resultant red gummy
oil was suspended in 30 mL of water, solid KOH (0.56 g, 10.0 mmol) was added
and stirred for 5 h. The yellow solid obtained was filtered, washed with water
150.8, 150.5, 150.2, 137.5, 137.1, 124.6, 123.0, 122.7, 122.3, 121.9, 121.7, 119.1,
117.9, 115.8. Selected FT-IR (KBr, cm ): 1634, 1603, 1455, 1415, 1384, 1216,
1198, 1124, 1094, 1002, 743, 729, 719, 693. Anal. calcd for C24H N : C, 69.22;
16 8
H, 3.87; N, 26.91. Found: C, 69.09; H, 3.81; N, 26.82. 1-((4-
pyridyl)methanimine)-3-(4-pyridyl)imidazo[1,5-a]pyridine (4b): Yield: 130 mg
À1
and dried in vacuum over fused CaCl
chromatographic separation using basic alumina column. Firstly compound 1-
(2-pyridyl)methanimine)-3-(2-pyridyl)imidazo[1,5-a]pyridine (2b) was eluted
2
. The dry solid was subjected to
+
+
(15%). mp 180 °C; ESI-Mass: calcd for C18
= 0.71 (1:1 ethylacetate/hexane). 400 MHz H NMR (d (J, Hz), CDCl
(1H, s), 8.76 (2H, d, 6.4), 8.70 (2H, d, 6.0), 8.31 (1H, d, 7.2), 7.95 (1H, d, 9.2), 7.81
(2H, d, 6.0), 7.77 (2H, d, 6.0), 6.98 (1H, t, 6.0), 6.77 (1H, t, 7.2). 100 MHz 13
NMR (d, CDCl ): 151.9, 150.7, 150.4, 143.9, 122.9, 122.7, 122.0, 121.8, 121.7,
119.0, 115.5. Selected FT-IR (KBr, cm ): 1628, 1595, 1492, 1411, 1301, 1251,
1177, 1138, 987, 841, 756, 737, 693, 547, 523. Anal. calcd for C18 : C,
H
13
N
5
300 found (M +H) 300.16.
1
(
R
f
3
): 9.25
with ethyl acetate/hexane (3:7) mixture and the yellow fibrous solid of 2b
was obtained after removal of the solvents. Yield of 2b: 150 mg (17%). Then 1-
C
(
3,5-bis(2-pyridyl)-1,2,4-triazolyl)-3-(2-pyridyl)imidazo[1,5-a]pyridine (2a) was
3
À1
eluted using dichloromethane. Yield of 2a: 390 mg (10%). The filtrate had a
strong ammonia smell, the pH of which was adjusted to 7-8 using 5 M HCl. The
aqueous solution was extracted with ether (3 Â 50 mL) and 3,5-bis(2-pyridyl)-
13 5
H N
72.23; H, 4.38; N, 23.40. Found: C, 72.04; H, 4.31; N, 23.33. Single crystals
suitable for X-ray study were obtained by slow evaporation of 1:1 ethylacetate/
hexane solution of 4b.
1
,2,4-triazole (1) was obtained as yellow solid after evaporating the ether. Yield
+
of 1: 1.42 g (52%). 2a: mp 210 °C; ESI-Mass: calcd for C24
H
16
N
8
416.150 found
): 10.04 (1H, d, 7.6), 8.81 (1H,
d, 4.8), 8.66 (1H, d, 4.8), 8.34 (2H, d, 7.2), 8.27 (1H, d, 7.6), 8.19 (1H, d, 8.4), 7.78
+
1
(
M +H) 417.13. 400 MHz H NMR (d (J, Hz), CDCl
3
8. (a) Geldard, J. F.; Lions, F. J. Org. Chem. 1965, 30, 318–319; (b) Cheng, L.; Zhang,
W.; Ye, B.; Lin, J.; Chen, X. Inorg. Chem. 2007, 46, 1135–1143.
9. Kulhánek, J.; Bureš, F.; Šimon, P.; Schweizer, W. B. Tetrahedron: Asymmetry
2008, 19, 2462–2469.
(
(
3H, m), 7.45 (1H, d, 8.8), 7.36 (1H, t, 6.8), 7.24 (2H, m), 6.94 (1H, t, 7.2), 6.83
13
3
1H, t, 7.2). 100 MHz C NMR (d, CDCl ): 161.8, 155.4, 150.5, 150.0, 149.4,
1
1
1
49.2, 148.1, 147.1, 136.8, 136.6, 132.1, 127.0, 126.6, 126.1, 124.5, 124.4, 124.1,
22.1, 122.0, 116.9, 114.3. Selected FT-IR (KBr, cm ): 1639, 1589, 1505, 1473,
417, 1385, 1359, 1160, 1091, 1014, 996, 952, 790, 742, 713, 695. Anal. calcd
10. X-ray diffraction data: 2a, (296(2) K, Mo
K
a
):
24 18 8
C H N O, 434.45, P-1,
À1
a = 8.4452(3), b = 9.2304(3), c = 14.4128(5) Å,
a
= 74.361(2), b = 74.632(2),
3
À3
À1
c
= 84.530(2)°, V = 1042.89(6) Å , Z = 2,
D
c
= 1.377 g cm
) = 0.0471, wR (I > 2
param., 2948 obs. refl., 3551 unique); 4b, (296(2) K, Mo
299.33, P2 /c, a = 9.3301(12), b = 4.7326(8), c = 32.194(4) Å, b = 95.529(9)°,
V = 1414.9(3) Å , Z = 4,
int = 0.0691, R (I > 2 ) = 0.0704, wR
refl., 1116 unique).
,
r
l
= 0.91 mm
) = 0.1486 (363
18 13 5
): C H N ,
,
for C24
H
16
N
8
: C, 69.22; H, 3.87; N, 26.91. Found: C, 69.03; H, 3.79; N, 26.75.
F(000) = 448,
Rint = 0.0263,
R
1
(I > 2
r
2
Single crystals suitable for X-ray study were grown by slow evaporation of
dichloromethane solution of 2a.
Compounds 3a, b and 4a, b were synthesized in similar yields by adopting the
same procedure described for 2a and 2b. 1-(3-(2-pyridyl)-5-(3-pyridyl)-1,2,4-
triazolyl)-3-(3-pyridyl)imidazo[1,5-a]pyridine (3a): Yield: 625 mg (16%). mp
K
a
1
3
À3
À1
D
c
= 1.405 g cm
(I > 2
,
l
= 0.89 mm
,
F(000) = 624,
R
1
r
2
r
) = 0.2083 (260 param., 887 obs.