J.C.P. Mayer et al. / Journal of Organometallic Chemistry 841 (2017) 1e11
9
1
2
d
¼ 7.92 (dt, J ¼ 8.2 Hz, J ¼ 1.8 Hz, 2 H); 7.38 (d, J ¼ 7.9 Hz, 2 H);
1373, 1331, 1266, 1167, 1117, 1067, 1042, 1017, 962, 930, 904, 859,
.38 (s, 3 H). 13C NMR (DMSO-d
41.9; 129.8; 127.1; 122.7; 21.0.
, 100 MHz):
d
¼ 168.9; 167.9; 151.8;
833, 814, 761, 725, 706, 598, 505, 484, 472, 427. H NMR (CDCl
1
2
1
6
3
,
400 MHz):
d
¼ 8.10 (d, J ¼ 6.2 Hz, 2 H); 7.74 (d, J ¼ 15.9 Hz, 1 H); 7.34
(
d, J ¼ 5.4 Hz, 2 H); 6.71 (d, J ¼ 16.0 Hz, 1 H); 4.60 (br, 2 H); 4.52 (br,
4
(
.2.5.3. 3-(4-Methoxyphenyl)-1,2,4-oxadiazole-5-carbohydrazide
2 H); 4.21 (s, 5 H); 2.45 (s, 3 H). HRMS-ESI(þ) m/z, calcd. for
1
þ
7c). Yield ¼ 1.264 g, 90% (white solid). H NMR (DMSO-d
6
,
C
23
H18FeN
4
O
2
[MþH] : 439.0857, Found: 439.0845.
1
2
4
00 MHz):
d
¼ 7.98 (dt, J ¼ 9.0 Hz, J ¼ 2.5 Hz, 2 H); 7.13 (dt,
1
2
1
3
J
¼ 9.0 Hz, J ¼ 2.5, 2 H); 3.84 (s, 3 H). C NMR (DMSO-d
6
,
4.2.6.3. (E)-3-(4-methoxyphenyl)-5-[5-(2-ferrocenylethen-1-yl)-
1
5
00 MHz):
d
¼ 168.8; 167.7; 162.0; 157.8; 151.8; 128.9; 117.8; 114.7;
1,3,4-oxadiazol-2-yl]-1,2,4-oxadiazole (8c). Yield ¼ 0.124 g, 55%
ꢀ
5.4.
(dark red solid); mp ¼ 164.5e167.5 C. Anal. Calcd. for C23
H18Fe-
4 3 2
N O $H O: C, 58.49; H, 4.27; N, 11.86; Found: C, 58.59; H, 4.28; N,
11.86%. FT-IR (KBr, cm ): 3414, 2361, 1616, 1525, 1493, 1444, 1413,
ꢁ1
4
.2.5.4. 3-(4-Chlorophenyl)-1,2,4-oxadiazole-5-carbohydrazide (7d).
1
Yield ¼ 1.428 g, 95% (white solid). H NMR (DMSO-d
6
, 400 MHz):
1374, 1264, 1177, 1156, 1105, 1031, 1003, 962, 900, 823, 755, 732, 697,
1
2
1
d
¼ 10.78 (br, 1 H); 8.04 (dt, J ¼ 8.7 Hz, J ¼ 2.2 Hz, 2 H); 7.66 (dt,
497, 481. H NMR (CDCl
3
, 400 MHz):
d
¼ 8.15 (br, 2 H); 7.73 (d,
1
2
13
J
¼ 8.7 Hz, J ¼ 2.2 Hz, 2 H); 4.95 (br, 2 H). C NMR (DMSO-d
¼ 169.2; 167.2; 151.6; 136.7; 129.5; 128.9; 124.4.
6
,
J ¼ 15.5 Hz, 1 H); 7.04 (br, 2 H); 6.70 (d, J ¼ 15.4 Hz, 1 H); 4.60 (br,
1
00 MHz):
d
2 H); 4.51 (br, 2 H); 4.20 (s, 5 H); 3.89 (s, 3 H). HRMS-ESI(þ) m/z,
þ
calcd. for C23
H18FeN
4
O
3
[MþH] : 455.0807, Found: 455.0796.
4
.2.5.5. 3-(4-trifluoromethylphenyl)-1,2,4-oxadiazole-5-
1
carbohydrazide (7e). Yield ¼ 1.306 g, 80% (white solid). H NMR
4.2.6.4. (E)-3-(4-chlorophenyl)-5-[5-(2-ferrocenylethen-1-yl)-1,3,4-
(
7
d
DMSO-d , 400 MHz):
6
d
¼ 10.84 (br, 1 H); 8.24 (d, J ¼ 8.1 Hz, 2 H);
oxadiazol-2-yl]-1,2,4-oxadiazole (8d). Yield ¼ 0.073 g, 32% (red
13
ꢀ
.96 (d, J ¼ 8.2 Hz, 2 H); 5.03 (br, 2H). C NMR (DMSO-d
6
,100 MHz):
solid); mp > 122 C (dec.). Anal. Calcd. for C22
H
15ClFeN
4
O
2
$2H
2
O: C,
¼ 169.5; 167.0; 151.6; 131.77 (q, J ¼ 32.1 Hz); 129.4; 128.0; 126.27
53.41; H, 3.87; N, 11.33; Found: C, 53.50; H, 3.91; N, 11.35%. FT-IR
ꢁ1
(
q, J ¼ 3.6 Hz); 123.7 (q, J ¼ 272.7 Hz).
(KBr, cm ): 3424, 3093, 2938, 2360, 1636, 1612, 1524, 1491, 1469,
447, 1425, 1372, 1335, 1307, 1253, 1173, 1159, 1104, 1043, 1028,
1
1
4
.2.6. (E)-3-aryl-5-[5-(2-ferrocenylethen-1-yl)-1,3,4-oxadiazol-2-
yl]-1,2,4-oxadiazoles (8a-e) [12]
1006, 975, 955, 912, 842, 759, 734, 720, 700, 637, 621, 528, 482. H
NMR (CDCl , 400 MHz):
3
d
¼ 8.16 (d, J ¼ 7.9 Hz, 2 H); 7.75 (d,
In a round-bottom flask with magnetic stirring, under argon
atmosphere, (E)-3-ferrocenylacrylic acid (3) (0.5 mmol), dichloro-
methane (7.0 mL), triethylamine (0.35 mL, 2.5 mmol) and the
proper 3-aryl-1,2,4-oxadiazole-5-carbohydrazide (7a-e) were
added and the mixture was stirred for 2 h at room temperature.
Then, 4-toluenesulfonyl chloride (0,286 g,1.5 mmol) was added and
the reaction was run for an additional 2 h at the same temperature.
After completion, the reaction was quenched by adding 37%
aqueous ammonia (5.0 mL) and stirring for 15 min. Water (10 mL)
was added to the resulting system and it was extracted with
dichloromethane (3 ꢂ 10 mL). The organic layer was dried over
J ¼ 15.8 Hz, 1 H); 7.53 (d, J ¼ 8.0 Hz, 2 H); 6.71 (d, J ¼ 16.3 Hz, 1 H);
4.61 (br, 2 H); 4.53 (br, 2 H); 4.21 (s, 5 H). HRMS-ESI(þ) m/z, calcd.
þ
for C22
H
15ClFeN
4
O
2
[MþH] : 459.0311, Found: 459.0301.
4.2.6.5. (E)-3-(4-trifluoromethylphenyl)-5-[5-(2-ferrocenylethen-1-
yl)-1,3,4-oxadiazol-2-yl]-1,2,4-oxadiazole (8e). Yield ¼ 0.057 g, 23%
ꢀ
(red solid); mp > 198 C (dec.). Anal. Calcd. for C23
H
15
F
3
FeN
4
O
2
: C,
56.12; H, 3.07; N, 11.38; Found: C, 56.21; H, 3.10; N, 11.41%. FT-IR
ꢁ
1
(KBr, cm ): 3415, 2918, 2360, 1633, 1601, 1524, 1448, 1408, 1372,
1332, 1207, 1174, 1102, 1043, 1012, 957, 924, 846, 811, 754, 732, 695,
1
551, 504, 486, 473. H NMR (CDCl
3
, 400 MHz):
d
¼ 8.35 (br, 2 H);
anhydrous MgSO
4
and filtered and the solvent was removed by
7.81 (d, J ¼ 7.5 Hz, 2 H); 7.76 (d, J ¼ 16.9 Hz, 1 H); 6.71 (d, J ¼ 15.9 Hz,
rotary evaporation. The crude product was purified by flash column
chromatography on silica-gel using hexane:ethyl acetate:di-
chloromethane (60:20:20, v/v/v) as the mobile phase. The solvent
was removed by rotary evaporation and the product was washed
with ethanol:water, 1:1 (v/v) in order to avoid previously unre-
moved impurities. The purified product was dried under reduced
pressure.
1 H); 4.61 (br, 2 H); 4.53 (br, 2 H); 4.21 (s, 5 H). HRMS-ESI(þ) m/z,
þ
calcd. for C23H
15
F
3
FeN
4
O
2
[MþH] : 493.0575, found: 493.0557.
4.2.7. (E)-2-Aryl-5-(2-ferrocenylethen-1-yl)-1,3,4-oxadiazoles
(11a-c) [12]
The procedure is analogous to that of 8a-e, using either benz-
hydrazide (10a), 4-methoxybenzhydrazide (10b) or 4-
chlorobenzhydrazide (10c) instead of hydrazides 7a-e.
4
2
.2.6.1. (E)-3-phenyl-5-[5-(2-ferrocenylethen-1-yl)-1,3,4-oxadiazol-
-yl]-1,2,4-oxadiazole (8a). Yield ¼ 0.108 g, 51% (dark red solid);
4.2.7.1. (E)-2-phenyl-5-(2-ferrocenylethen-1-yl)-1,3,4-oxadiazoles
ꢀ
ꢀ
mp > 194 C (dec.). Anal. Calcd. for C22
H16FeN
4
O
2
$H
2
O: C, 59.75; H,
(11a). Yield ¼ 0.109 g, 61% (dark red solid); mp ¼ 144.7e148.7 C.
ꢁ1
4
3
1
.10; N, 12.67; Found: C, 59.76; H, 4.11; N, 12.62%. FT-IR (KBr, cm ):
415, 3073, 2360, 1638, 1621, 1523, 1466, 1444, 1375, 1343, 1296,
278, 1249, 1187, 1175, 1106, 1045, 1031, 1007, 962, 927, 904, 841,
2
Anal. Calcd. for C20H16FeN O: C, 67.44; H, 4.53; N, 7.86; Found: C,
ꢁ
1
67.51; H, 4.55; N, 7.87%. FT-IR (KBr, cm ): 3415, 3074, 2360, 1644,
1562, 1549, 1529, 1482, 1450, 1409, 1311, 1260, 1244, 1155, 1102,
1
8
4
20, 785, 744, 723, 703, 689, 624, 493, 481, 465. H NMR (CDCl
3
,
1090, 1068, 1042, 1027, 1001, 954, 833, 810, 774, 742, 719, 697, 689,
1
00 MHz):
d
¼ 8.21 (d, J ¼ 5.7 Hz, 2 H); 7.74 (d, J ¼ 16.1 Hz, 1 H);
562, 530, 483, 426. H NMR (CDCl
3
, 400 MHz):
d
¼ 8.11 (d, J ¼ 6.4 Hz,
7
2
.55e7.53 (m, 3 H); 6.70 (d, J ¼ 16.2 Hz, 2 H); 4.60 (br, 2 H); 4.51 (br,
2 H); 7.55e7.53 (m, 3 H); 7.50 (d, J ¼ 16.2 Hz, 1 H); 6.71 (d,
13
13
H); 4.20 (s, 5 H). C RMN (CDCl
3
, 400 MHz):
d
¼ 159.5; 166.7;
J ¼ 16.2 Hz, 1 H); 4.58 (br, 2H); 4.46 (br, 2 H); 4.21 (s, 5 H). C RMN
163.0; 152.1; 144.0; 131.9; 129.0; 127.8; 125.6; 104.8; 78.8; 71.5;
(CDCl
3
, 100 MHz):
d
¼ 164.6; 163.5; 139.5; 131.5; 129.0; 126.8;
þ
6
4
9.9; 68.6. HRMS-ESI(þ) m/z, calcd. for C22
H16FeN
4
O
2
[MþH] :
124.1; 106.9; 79.7; 70.7; 69.6; 68.1. HRMS-ESI(þ) m/z, calcd. for
þ
25.0701, Found: 425.0690.
C
20
H16FeN
2
O [MþH] : 357.0690, found: 357.0680.
4.2.6.2. (E)-3-(4-methylphenyl)-5-[5-(2-ferrocenylethen-1-yl)-1,3,4-
4.2.7.2. (E)-2-(4-methylphenyl)-5-(2-ferrocenylethen-1-yl)-1,3,4-
oxadiazol-2-yl]-1,2,4-oxadiazole (8b). Yield ¼ 0.110 g, 50% (dark red
oxadiazoles (11b). Yield
¼
0.031 g, 16% (red solid);
18FeN : C, 68.13; H,
ꢀ
ꢀ
solid); mp ¼ 174.9e177.0 C. Anal. Calcd. for C23
H18FeN
4
O
2
: C,
mp ¼ 166.6e167.4 C. Anal. Calcd. for C21
H
2 2
O
ꢁ
1
6
3.03; H, 4.14; N, 12.78; Found: C, 63.12; H, 4.16; N, 12.80%. FT-IR
4.90; N, 7.57; Found: C, 68.17; H, 4.91; N, 7.63%. FT-IR (KBr, cm ):
3452, 2360, 1644, 1613, 1533, 1498, 1440, 1307, 1257, 1175, 1104,
ꢁ1
(
KBr, cm ): 3416, 3084, 2920, 2360, 1709, 1631, 1524, 1448, 1418,