Akhila K. Sahoo et al.
8.81 (s, 1H), 8.34 (s, 1H), 7.92 (s, 1H), 4.12 ppm (s, 3H); 13C NMR
(101 MHz, [D6]DMSO): d=155.9, 153.7, 146.0, 137.9, 135.7, 134.4, 124.0,
113.8, 59.1 ppm; IR (KBr): n˜ =3130, 3057, 1601, 1543, 1510, 1340,
671 cmꢀ1; MS (EI): m/z (%): 266 (100) [M+1]+, 221 (4); elemental analy-
sis calcd (%) for C9H7N5O5: C 40.76, H 2.66, N 26.41; found: C 40.68,
H 2.71, N 26.35.
n˜ =3422, 3134, 1591, 1539, 1365, 640 cmꢀ1; MS (EI): m/z (%): 251 (100)
[M+1]+, 169 (10), 137 (10); elemental analysis calcd (%) for C8H6N6O4:
C 38.41, H 2.42, N 33.49; found: C 38.56, H 2.35, N 33.41.
2,4-Dintro-5-(1H-1,2,4-triazol-1-yl)aniline (6b): 225 mg (79% yield);
yellow solid; m.p. 2408C; DTA=3058C (exotherm); Rf =0.57 (n-hexane/
EtOAc, 1:1); 1H NMR (400 MHz, [D6]DMSO): d=9.06 (s, 1H), 8.83 (s,
1H), 8.50 (br s, 2H; NH2), 8.28 (s, 1H), 7.23 ppm (s, 1H); 13C NMR
(101 MHz, [D6]DMSO): d=153.2, 149.2, 145.9, 135.5, 130.8, 128.5, 127.0,
117.8 ppm; IR (KBr): n˜ =3450, 3088, 1575, 1510, 1325, 661 cmꢀ1; MS
(EI): m/z (%): 249 (100) [Mꢀ1]+, 237 (12), 221 (3); elemental analysis
calcd (%) for C8H6N6O4: C 38.41, H 2.42, N 33.49; found: C 38.26,
H 2.51, N 33.65.
1-(5-Methoxy-2,6-dinitrophenyl)-1H-1,2,4-triazole (5e’): 141 mg (23%
yield); orange solid; m.p. 1368C; DTA=2528C (exotherm); Rf =0.62 (n-
hexane/EtOAc, 1:1); 1H NMR (500 MHz, [D6]DMSO): d=8.87 (s, 1H),
8.77 (d, J=1.5 Hz, 1H), 8.05 (d, J=1.5 Hz, 1H), 7.87 (s, 1H), 4.12 ppm
(s, 3H); 13C NMR (101 MHz, [D6]DMSO): d=156.0, 138.3, 136.0, 134.7,
134.3, 127.3, 124.1, 114.5, 59.1 ppm; IR (KBr): n˜ =3138, 2924, 1608, 1525,
1338, 725 cmꢀ1; MS (EI): m/z (%): 266 (100) [M+1]+, 250 (6), 236 (5),
221 (9), 205 (6); elemental analysis calcd (%) for C9H7N5O5: C 40.76,
H 2.66, N 26.41; found: C 40.61, H 2.75, N 26.31.
2,4-Dintro-6-(1H-1,2,4-triazol-1-yl)aniline (6c): 391 mg (82% yield);
yellow solid; m.p. 2168C; DTA=3078C (exotherm); Rf =0.63 (n-hexane/
EtOAc, 1:1); 1H NMR (400 MHz, [D6]DMSO): d=9.02 (s, 1H), 8.94 (d,
J=0.8 Hz, 1H), 8.50 (s, 1H), 8.38 (d, J=0.8 Hz, 1H), 8.12 ppm (br s, 2H;
NH2); 13C NMR (101 MHz, [D6]DMSO): d=153.7, 146.8, 145.4, 134.2,
131.5, 127.4, 125.3, 124.3 ppm; IR (KBr): n˜ =3454, 3086, 1539, 1402, 1327,
706 cmꢀ1; MS (EI): m/z (%): 251 (100) [M+1]+, 169 (12), 137 (9); ele-
mental analysis calcd (%) for C8H6N6O4: C 38.41, H 2.42, N 33.49; found:
C 38.31, H 2.51, N 33.65.
1-(2-Methoxy-3,5-dinitrophenyl)-1H-1,2,4-triazole (5k): 221 mg (88%
yield); yellow solid; m.p. 978C; DTA=2808C (exotherm); Rf =0.40 (n-
hexane/EtOAc, 1:1); 1H NMR (400 MHz, [D6]DMSO): d=9.13 (s, 1H),
8.90 (d, J=2.8 Hz, 1H), 8.76 (d, J=2.8 Hz, 1H), 8.40 (s, 1H), 3.74 ppm
(s, 3H); 13C NMR (101 MHz, [D6]DMSO): d=153.1, 151.0, 146.5, 144.1,
142.5, 132.3, 125.1, 121.0, 63.4 ppm; IR (KBr): n˜ =3153, 3057, 1610, 1537,
1344, 979 cmꢀ1; MS (EI): m/z (%): 266 (100) [M+1]+, 223 (4), 191 (8),
147 (6), 106 (6), 78 (31); elemental analysis calcd (%) for C9H7N5O5:
C 40.76, H 2.66, N 26.41; found: C 40.63, H 2.61, N 26.55.
General Procedure for the Synthesis of Compounds 9
A mixture of 3-nitro-1,2,4-triazole (1.2 equiv) and NaH (2.0 equiv) was
stirred in THF (5.0 mL for 1.0 mmol) in a 25 mL two-necked flask under
an argon atmosphere at 08C for 30 min. Then, the nitro-substituted aryl
chloride (1.0 equiv) was added and the mixture was stirred at RT for 6 h.
Upon completion of the reaction, the mixture was diluted with CH2Cl2
(30 mL) and filtered. The filtrate was evaporated under reduced pressure
and the crude residue was purified by column chromatography on silica
gel.
1-(3,4-dinitrophenyl)-1H-1,2,4-triazole (4g): 181 mg (73% yield); yellow
solid; m.p. 1298C; DTA=2718C; Rf =0.76 (n-hexane/EtOAc, 2:3);
1H NMR (400 MHz, [D6]DMSO): d=9.58 (s, 1H), 8.74 (d, J=1.6 Hz,
1H), 8.48 (d, J=8.8 Hz, 1H), 8.43 (d, J=1.2 Hz, 1H), 8.41 ppm (s, 1H);
13C NMR (101 MHz, [D6]DMSO): d=154.0, 144.6, 143.9, 140.8, 139.7,
128.4, 123.7, 116.2 ppm; IR (KBr): n˜ =3128, 3068, 1610, 1561, 1339,
673 cmꢀ1; MS (EI): m/z (%): 236 (100) [M+1]+, 220 (4), 208 (10), 193
(4); elemental analysis calcd (%) for C8H5N5O4: C 40.86, H 2.14, N 29.78;
found: C 40.71, H 2.18, N 29.61.
1-[2,6-Dinitro-4-(trifluoromethyl)phenyl]-3-nitro-1H-1,2,4-triazole (9a):
256 mg (70% yield); yellow solid; m.p. 1668C; DTA=2828C (exotherm);
Rf =0.48 (n-hexane/EtOAc, 4:1); 1H NMR (400 MHz, [D6]DMSO): d=
9.46 (s, 1H), 9.15 ppm (s, 2H); 13C NMR (125 MHz, [D6]DMSO): d=
163.8, 150.7, 146.6, 133.4 (q, J=35 Hz), 128.5 (q, J=3.7 Hz), 126.9, 126.1,
121.9 ppm (q, J=272 Hz); 19F NMR (376 MHz, [D6]DMSO): d=
ꢀ61.78 ppm; IR (KBr): n˜ =2920, 1556, 1375, 1265, 1167, cmꢀ1; MS (EI):
m/z (%): 349 (100) [M+1]+, 320 (4), 305 (9), 243 (4), 151 (4), 106 (4); ele-
mental analysis calcd (%) for C9H3F3N6O6: C 31.05, H 0.87, N 24.14;
found: 31.12, H 0.95, N 24.06.
1-[4-Nitro-3-(trifluoromethyl)phenyl]-1H-1,2,4-triazole
(4i):
366 mg
(80% yield); yellow solid; m.p. 1158C; DTA=2108C; Rf =0.44 (n-
hexane/EtOAc, 1:1); 1H NMR (400 MHz, [D6]DMSO): d=9.61 (s, 1H),
8.48 (s, 1H), 8.44–8.39 (m, 2H); 8.38 ppm (s, 1H); 13C NMR (101 MHz,
[D6]DMSO): d=153.8, 145.8, 144.3, 140.0, 128.3, 124.3, 123.5 (q, J=
34.2 Hz), 122.1 (q, J=276 Hz), 118.8 ppm (q, J=2.5 Hz); 19F NMR
(376 MHz, [D6]DMSO): d=ꢀ58.99 ppm; IR (KBr): n˜ =3115, 1602, 1548,
1359, 1286, 715 cmꢀ1; MS (EI): m/z (%): 259 (M+ +1, 100), 241 (20), 233
(10), 217 (12), 203 (5); elemental analysis calcd (%) for C9H5N4O2F3:
C 41.87, H 1.95, N 21.70; found: C 41.72, H 2.06, N 21.89.
1-[2,4-Dinitro-6-(trifluoromethyl)phenyl]-3-nitro-1H-1,2,4-triazole (9b):
269 mg (74% yield); yellow solid; m.p. 1658C; DTA=3158C (exotherm);
Rf =0.58 (n-hexane/EtOAc, 9:1); 1H NMR (400 MHz, [D6]DMSO): d=
9.48 (s, 1H), 9.36 (d, J=2.4 Hz, 1H), 9.08 ppm (d, J=2.4 Hz, 1H);
13C NMR (101 MHz, [D6]DMSO): d=163.8, 151.1, 149.6, 147.3, 131.1,
129.9 (q, J=33.3 Hz), 127.7 (q, J=4.0 Hz), 125.9, 121.2 ppm (q, J=
277 Hz); 19F NMR (470 MHz, [D6]DMSO): d=ꢀ58.3 ppm; IR (KBr): n˜ =
2964, 1556, 1512, 1430, 1336, 1287, 679 cmꢀ1; MS (EI): m/z (%): 349 (100)
[M+1]+, 230 (12), 154 (13), 122 (4); elemental analysis calcd (%) for
C9H3F3N6O6: C 31.05, H 0.87, N 24.14; found: 31.12, H 0.91, N 24.07.
1-[4-Nitro-2-(trifluoromethyl)phenyl]-1H-1,2,4-triazole (4m): 405 mg
(66% yield); yellow oil; Rf =0.50 (n-hexane/EtOAc, 3:2); 1H NMR
(400 MHz, [D6]DMSO): d=9.03 (s, 1H), 8.70 (dd, J=8.4, 2.4 Hz, 1H),
8.66 (J=2.4 Hz, 1H), 8.35 (s, 1H), 8.07 ppm (d, J=8.8 Hz, 1H);
13C NMR (101 MHz, [D6]DMSO): d=153.3, 148.2, 146.6, 139.6, 131.3,
129.3, 126.5 (q, J=33.3 Hz), 123.5 (d, J=5.05 Hz), 122.2 ppm (q, J=
275 Hz); 19F NMR (376 MHz, [D6]DMSO): d=ꢀ58.59 ppm; IR (KBr):
n˜ =3096, 2922, 1624, 1541, 1356, 1315, 671 cmꢀ1; MS (EI): m/z (%): 259
(100) [M+1]+, 220 (5), 196 (4), 119 (4), 106 (47), 97 (12), 74 (9); elemen-
tal analysis calcd (%) C9H5N4O2F3: C 41.87, H 1.95, N 21.70; found:
C 42.12, H 1.91, N 21.62.
1-(3-Methyl-2,4,6-trinitrophenyl)-3-nitro-1H-1,2,4-triazole (9c):
A mix-
ture of compound 8 (131 mg, 1.14 mmol), 2-chloro-4-methyl-1,3,5-trinitro-
benzene (7c; 200 mg, 0.957 mmol), and pyridine (98 mg, 1.24 mmol) in
MeCN (5.0 mL) was stirred at RT for 6 h. Upon completion of the reac-
tion, the solvent was evaporated under reduced pressure and the crude
residue was purified by column chromatography on silica gel to afford
compound 9c. 176 mg; 54% yield; yellow solid; m.p. 1608C; DTA=
2708C (exotherm); Rf =0.5 (n-hexane/EtOAc, 3:1); 1H NMR (400 MHz,
[D6]DMSO): d=9.44 (s, 1H), 9.27 (s, 1H) 2.57 ppm (s, 3H); 13C NMR
(101 MHz, [D6]DMSO): d=163.9, 151.4, 150.9, 149.2, 146.7, 143.2, 133.5,
124.7, 15.4 ppm; IR (KBr): n˜ =2920, 2854, 1572, 1550, 1336, 1314,
651 cmꢀ1; MS (EI): m/z (%): 340 (100) [M+1]+, 296 (21); elemental anal-
ysis calcd (%) for C9H5N7O8: C 31.87, H 1.49, N 28.91; found: C 31.72,
H 1.45, N 28.85.
General Procedure for the Synthesis of Compounds 6
An aqueous solution of ammonia (0.4 mL) was added to a solution of
compound 5d/5e/5k (1.0 mmol) in MeCN (25 mL) and the resulting solu-
tion was heated at reflux for 18 h. Upon completion of the reaction, the
mixture was cooled to RT. The reaction mixture precipitated during cool-
ing. The solid was filtered, washed with Et2O, and dried in air to give the
crude product, which was purified by column chromatography on silica
gel.
2,6-Dintro-4-(1H-1,2,4-triazol-1-yl)aniline (6a): 299 mg (84% yield);
orange solid; m.p. 2708C; DTA=2938C (exotherm); Rf =0.60 (n-hexane/
EtOAc, 1:1); 1H NMR (400 MHz, [D6]DMSO): d=9.42 (s, 1H), 8.93 (s,
2H), 8.49 (s, 2H; NH2), 8.28 ppm (s, 1H); 13C NMR (101 MHz,
[D6]DMSO): d=152.9, 143.2, 140.2, 135.5, 125.1, 123.7 ppm; IR (KBr):
3-Nitro-1-[2-nitro-4-(trifluromethyl)phenyl]-1H-1,2,4-triazole (9d):
A
mixture of compound 8 (177 mg, 1.5 mmol), 1-chloro-2-nitro-4-(trifluoro-
methyl)benzene (7d; 250 mg, 1.1 mmol), and Na2CO3 (233 mg, 2.0 mmol)
11
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Chem. Asian J. 2013, 00, 0 – 0
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
These are not the final page numbers! ÞÞ