Synthesis, Characterization and Energetic Properties of 1,3,4-Oxadiazoles
using a mixture of gradient hexanes/AcOEt as eluent to give 1,3,4-
oxadiazoles 4a–o. Samples for analysis were purified by recrystalli-
zation from acetone/water.
7.96 (t, J = 8.0 Hz, 1 H) ppm. 13C NMR (75 MHz, [D6]DMSO): δ
= 163.7, 162.0, 148.8, 148.3, 133.2, 131.4, 126.9, 126.7, 125.9, 124.4,
121.6, 121.3 ppm. C14H7N5O7 (357.24): calcd. C 47.07, H 1.98, N
19.60; found C 47.44, H 1.76, N 19.37.
2,5-Bis(4-nitrophenyl)-1,3,4-oxadiazole (4a): Prepared from 1c and
3c. Yield 71%, colorless solid, m.p. 316-317 °C (ref.[34] 314–316 °C).
1H NMR (300 MHz, [D6]DMSO): δ = 8.49 (d, J = 8.7 Hz, 4 H),
8.44 (d, J = 9.0 Hz, 4 H) ppm. 13C NMR (75 MHz, [D6]DMSO):
δ = 165.7, 150.0, 136.3, 130.7, 123.7 ppm. C14H8N4O5 (312.24):
calcd. C 53.85, H 2.58, N 17.94; found C 54.19, H 2.32, N 17.58.
2-(3,5-Dinitrophenyl)-5-(2-nitrophenyl)-1,3,4-oxadiazole (4i): Pre-
pared from 1a and 3e. Yield 69%, off-white solid, m.p. 278–280 °C.
1H NMR (300 MHz, [D6]DMSO): δ = 9.09 (d, J = 1.8 Hz, 2 H),
9.03 (t, J = 2.1 Hz, 1 H), 8.32–8.28 (m, 1 H), 8.27–8.23 (m, 1 H),
8.04–7.95 (m, 2 H) ppm. 13C NMR (75 MHz, [D6]DMSO): δ =
162.1, 161.6, 148.8, 147.9, 133.9, 133.6, 131.6, 126.7, 125.6, 124.8,
121.4, 116.2 ppm. C14H7N5O7 (357.24): calcd. C 47.07, H 1.98, N
19.60; found C 46.97, H 1.66, N 19.43.
2-(3-Nitrophenyl)-5-(4-nitrophenyl)-1,3,4-oxadiazole (4b): Prepared
from 1c and 3b or 1b and 3c. Yield 66%, colorless solid, m.p. 249–
251 °C (ref.[35] 248–249 °C). 1H NMR NMR (300 MHz, [D6]-
DMSO + [D6]acetone): δ = 8.88 (s, 1 H), 8.61 (d, J = 7.5 Hz, 1 H),
8.55–8.40 (m, 5 H), 7.97 (t, J = 7.8 Hz, 1 H) ppm. 13C NMR
(75 MHz, [D6]DMSO + [D6]acetone): δ = 163.4, 163.4, 149.4,
148.4, 132.9, 131.3, 128.7, 128.3, 126.7, 124.7, 124.6, 121.4 ppm.
C14H8N4O5 (312.24): calcd. C 53.85, H 2.58, N 17.94; found C
53.54, H 2.48, N . 18.00.
2-(2,4-Dinitrophenyl)-5-(4-nitrophenyl)-1,3,4-oxadiazole (4j): Pre-
pared from 1c and 3d. Yield 71%, colorless solid, m.p. 223–225 °C.
1H NMR (300 MHz, [D6]DMSO): δ = 9.03 (s, 1 H), 8.76 (dd, J =
8.6, 2.3 Hz, 1 H), 8.53 (d, J = 8.7 Hz, 1 H), 8.48 (d, J = 7.2 Hz, 2
H), 8.36 (d, J = 8.7 Hz, 2 H) ppm. 13C NMR (75 MHz, [D6]-
DMSO): δ = 163.9, 160.0, 149.6, 149.5, 147.9, 132.6, 128.4, 128.1,
127.7, 124.8, 121.0 120.1 ppm. HRMS (DART-TOF): calcd. for
C14H11N6O7 [M + NH4]+ 375.0684, found 375.0681.
2,5-Bis(3-nitrophenyl)-1,3,4-oxadiazole (4c): Prepared from 1b and
3b. Yield 70%, colorless solid, m.p. 236–237 °C (ref.[36] 233.5–
1
234 °C). H NMR (300 MHz, [D6]DMSO): δ = 8.86 (s, 2 H), 8.60
2-(2,4-Dinitrophenyl)-5-(3-nitrophenyl)-1,3,4-oxadiazole (4k): Pre-
pared from 1c and 3d. Yield 79%, colorless solid, m.p. 250–251 °C.
1H NMR (300 MHz, [D6]DMSO): δ = 9.03 (d, J = 2.4 Hz, 1 H),
8.78 (t, J = 2.1 Hz, 1 H), 8.74 (dd, J = 8.6, 2.3 Hz, 1 H), 8.57 (d,
J = 9.0 Hz, 1 H), 8.53 (d, J = 8.1 Hz, 1 H), 8.52 (d, J = 8.1 Hz, 1
H), 7.97 (t, J = 8.1 Hz, 1 H) ppm. 13C NMR (75 MHz, [D6]-
DMSO): δ = 163.7, 159.7, 149.5, 148.3, 147.9, 133.0, 132.6, 131.5,
127.6, 127.1, 124.1, 121.5, 120.9, 120.1 ppm. C14H7N5O7 (357.24):
calcd. C 47.07, H 1.98, N 19.60; found C 47.28, H 1.68, N 19.30.
(d, J = 7.5 Hz, 2 H), 8.49 (d, J = 8.1 Hz, 2 H), 7.94 (t, J = 8.1 Hz,
2 H) ppm. 13C NMR (75 MHz, [D6]DMSO): δ = 163.1, 148.3,
133.0, 131.3, 126.6, 124.6, 121.4 ppm. C14H8N4O5 (312.24): calcd.
C 53.85, H 2.58, N 17.94; found C 53.64, H 2.35, N 17.58.
2-(2-Nitrophenyl)-5-(4-nitrophenyl)-1,3,4-oxadiazole (4d): Prepared
from 1a and 3c. Yield 82%, brown solid, m.p. 221–223 °C (ref.[37]
224–225 °C). 1H NMR (300 MHz, [D6]DMSO): δ = 8.45 (d, J =
9.0 Hz, 2 H), 8.31 (d, J = 9.0 Hz, 2 H), 8.25–8.18 (m, 2 H), 8.03–
7.93 (m, 2 H) ppm. 13C NMR (75 MHz, [D6]DMSO): δ = 163.5,
161.5, 149.5, 147.9, 133.8, 131.5, 128.4, 128.2, 124.9, 124.8,
116.6 ppm. C14H8N4O5 (312.24): calcd. C 53.85, H 2.58, N 17.94;
found C 53.88, H 2.33, N 17.75.
2-(2,4-Dinitrophenyl)-5-(2-nitrophenyl)-1,3,4-oxadiazole (4l): Pre-
pared from 1d and 3a. Yield 53%, colorless solid, m.p. 199–201 °C.
1H NMR (300 MHz, [D6]DMSO): δ = 9.01 (s, 1 H), 8.73 (d, J =
8.4 Hz, 1 H), 8.41 (d, J = 8.4 Hz, 1 H), 8.25 (d, J = 7.8 Hz, 1 H),
8.13 (d, J = 6.3 Hz, 1 H), 8.04–7.94 (m, 2 H) ppm. 13C NMR
(75 MHz, [D6]DMSO): δ = 161.9, 160.0, 149.6, 147.9, 134.0, 133.9,
132.6, 131.5, 127.8, 125.0, 120.8, 120.2, 116.2 ppm. C14H7N5O7
(357.24): calcd. C 47.07, H 1.98, N 19.60; found C 47.32, H 1.60,
N 19.28.
2-(2-Nitrophenyl)-5-(3-nitrophenyl)-1,3,4-oxadiazole (4e): Prepared
from 1a and 3b. Yield 77%, colorless solid, m.p. 177–178 °C (ref.[35]
166–168 °C). 1H NMR (300 MHz, [D6]DMSO): δ = 8.73 (t, J =
2.1 Hz, 1 H), 8.52–8.45 (m, 2 H), 8.22 (dd, J = 6.5, 2.3 Hz, 2 H),
8.02–7.91 (m, 3 H) ppm. 13C NMR (75 MHz, [D6]DMSO): δ =
163.3, 161.2, 148.3, 147.9, 133.7, 132.8, 131.5, 131.5, 126.8, 124.8,
124.3, 121.3, 116.6 ppm. C14H8N4O5 (312.24): calcd. C 53.85, H
2.58, N 17.94; found C 53.90, H 2.31, N 17.78.
2,5-Bis(3,5-dinitrophenyl)-1,3,4-oxadiazole (4m): Prepared from 1e
and 3e. Yield 74%, colorless solid, m.p. 355–357 °C (ref.[39] 351–
1
353 °C). H NMR (499 MHz at 100 °C, [D6]DMSO): δ = 9.29 (d,
J = 2.0 Hz, 4 H), 9.08 (t, J = 1.9 Hz, 2 H) ppm. 13C NMR
(126 MHz at 100 °C, [D6]DMSO): δ = 163.1, 149.6, 127.5, 126.5,
122.0 ppm. C14H6N6O9 (402.24): calcd. C 41.80, H 1.50, N 20.89;
found C 42.10, H 1.22, N 20.52.
2,5-Bis(2-nitrophenyl)-1,3,4-oxadiazole (4f): Prepared from 1a and
3a. Yield 75%, colorless solid, m.p. 200–202 °C (ref.[38] 195–
196 °C). 1H NMR (300 MHz, [D6]DMSO): δ = 8.18 (d, J = 6.9 Hz,
2 H), 8.06 (d, J = 6.6 Hz, 2 H), 7.96–7.87 (m, 4 H) ppm. 13C NMR
(75 MHz, [D6]DMSO): δ = 161.4, 147.9, 133.8, 131.4, 124.9,
116.4 ppm. C14H8N4O5 (312.24): calcd. C 53.85, H 2.58, N 17.94;
found C 53.83, H 2.34, N 18.23.
2-(2,4-Dinitrophenyl)-5-(3,5-dinitrophenyl)-1,3,4-oxadiazole
(4n):
Prepared from 1d and 3e. Yield 58%, off-white prisms, m.p. 225–
1
227 °C. H NMR (300 MHz, [D6]DMSO): δ = 9.14 (s, 2 H), 9.05
(s, 2 H), 8.76 (d, J = 8.7 Hz, 1 H), 8.65 (d, J = 8.7 Hz, 1 H) ppm.
13C NMR (75 MHz, [D6]DMSO): δ = 162.6, 160.1, 149.6, 148.8,
147.9, 132.8, 127.6, 126.8, 125.4, 121.7, 120.5, 120.1 ppm.
C14H6N6O9 (402.24): calcd. C 41.80, H 1.50, N 20.89; found C
42.07, H 1.20, N 20.56.
2-(3,5-Dinitrophenyl)-5-(4-nitrophenyl)-1,3,4-oxadiazole (4g): Pre-
pared from 1e and 3c. Yield 77%, colorless solid, m.p. 279–281 °C
(ref.[37] 277.5–278.0 °C). 1H NMR (300 MHz, [D6]DMSO): δ = 9.18
(d, J = 1.5 Hz, 2 H), 9.03 (t, J = 1.5 Hz, 1 H), 8.50 (d, J = 9.0 Hz,
2 H), 8.44 (d, J = 8.7 Hz, 2 H) ppm. 13C NMR (75 MHz, [D6]-
DMSO): δ = 163.7, 162.2, 149.5, 148.8, 128.5, 128.3, 126.7, 125.9,
124.6, 121.4 ppm. C14H7N5O7 (357.24): calcd. C 47.07, H 1.98, N
19.60; found C 47.32, H 1.67, N 19.21.
2,5-Bis(2,4-dinitrophenyl)-1,3,4-oxadiazole Monohydrate (4o): Pre-
pared from 1d and 3d. Yield 75%, colorless solid, m.p. 306–307 °C.
1H NMR (300 MHz, [D6]DMSO): δ = 11.41 (s, 2 H), 8.83 (d, J =
1.8 Hz, 2 H), 8.69 (dd, J = 8.4, 2.1 Hz, 2 H), 8.00 (d, J = 8.4 Hz,
2 H) ppm. 13C NMR (75 MHz, [D6]DMSO): δ = 162.9, 148.4,
147.1, 134.8, 131.3, 128.5, 119.9 ppm. HRMS (DART-TOF): calcd.
for C14H12N7O10 [M + NH4]+ 438.0640, found 438.0651.
2-(3,5-Dinitrophenyl)-5-(3-nitrophenyl)-1,3,4-oxadiazole (4h): Pre-
pared from 1e and 3b. Yield 63%, colorless solid, m.p. 228–230 °C.
1H NMR (300 MHz, [D6]DMSO): δ = 9.23 (s, 2 H), 9.03 (s, 1 H),
8.96 (s, 1 H), 8.69 (d, J = 7.5 Hz, 1 H), 8.52 (d, J = 7.5 Hz, 1 H),
Eur. J. Org. Chem. 2015, 5183–5188
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