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M. R. MANNAM ET AL.
[M þ H]þ (100). HRMS (FAB) Calc.: C13H11F4N5O: 348.13 [M þ H]þ (100). HRMS (FAB) Calc.: C13H10F5N5O:
329.08997; Found: 330.0967 [M þ Hþ].
347.08055; Found: 348.0952 [M þ Hþ].
N-(4-Bromophenyl)-3-(trifluoromethyl)-5,6,7,8-
tetrahydro-[1, 2, 4]triazolo[4,3-a]pyrazine-7-
carboxamide (13b)
N-(4-Methylcyclohexyl)-3-(trifluoromethyl)-5,6,7,8-
tetrahydro-[1, 2, 4]triazolo[4,3-a]pyrazine-7-
carboxamide (13e)
Off-white solid; m.r.: 218-221 ꢀC. IR (KBr, ꢀ~/cmꢁ1): 3407 Pale brown powder; m.r.: 216-219 ꢀC. IR (KBr, ꢀ~/cmꢁ1):
(N-H, str); 1668 (-C=O, str); 1533 (C=N, str); 1147 (CF3, 3302 (N-H, str); 1637 (C=O, str); 1550 (C=N, str); 1113
1
str); 835 (C-Br, str). 1H NMR (400 MHz; DMSO-d6), d, (CF3, str). H NMR (400 MHz; DMSO-d6), d, ppm, (J, Hz):
ppm, (J, Hz): 3.96-3.98 (2H, t, J ¼ 5.2, Piperazine); 4.22-4.24 0.85-0.86 (3H, m, Cyclohexyl); 0.88- 0.99 (2H, m,
(2H, t, J ¼ 5.2, Piperazine); 4.96 (2H, s, Piperazine); 7.42- Cyclohexyl); 1.16-1.32 (3H, m, Cyclohexyl); 1.63-1.66 (2H,
7.48 (4H, m, Ar-H); 8.99 (1H, s, NH). 13C NMR (100 MHz; m, Cyclohexyl); 1.75- 1.77 (2H, m, Cyclohexyl); 3.34-3.42
DMSO-d6), d, ppm, (J, Hz): 40.03 (-CH2-CH2-); 40.92 (1H, m, Cyclohexyl); 3.80-3.83 (2H, t, J ¼ 5.2, Piperazine);
(-CH2-CH2-); 43.32 (-CH2-); 113.88 (C Ar); 117.14 (d, 4.12-4.14 (2H, t, J ¼ 5.2, Piperazine); 4.77 (2H, s,
J ¼ 268.0, CF3); 121.70 (C Ar); 131.19 (C Ar); 139.41 (C Ar); Piperazine); 6.60 (1H, s, NH). 13C NMR (100 MHz; DMSO-
142.33 (C Ar); 151.07 (C=O); 154.34 (C Ar). LC-MS m/z d6), d, ppm, (J, Hz): 22.17 (C-Cyclohexane); 31.59 (C-
(rel, %): 390.00 [M þ H]þ (100); 392.00 [M þ H þ 2]þ (97). Cyclohexane);
32.71
(C-Cyclohexane);
33.81
(C-
HRMS (FAB) Calc.: C13H11BrF3N5O: 389.00990; Found: Cyclohexane); 40.12 (-CH2-CH2-); 40.60 (-CH2-CH2-); 43.25
390.0154 [M þ Hþ].
(-CH2-); 49.48 (C-Cyclohexane); 117.10 (d, J ¼ 269.0, CF3);
142.25 (C, Ar); 151.33 (C=O); 156.07 (C, Ar). LC-MS m/z
(rel, %): 332.25 [M þ H]þ (100). HRMS (FAB) Calc.:
C14H20F3N5O: 331.16199; Found: 332.1682 [M þ Hþ].
N-(3-Chlorophenyl)-3-(trifluoromethyl)-5,6,7,8-
tetrahydro-[1, 2, 4]triazolo[4,3-a]pyrazine-7-
carboxamide (13c)
N-(4-Fluorophenyl)-3-(trifluoromethyl)-5,6,7,8-
tetrahydro-[1, 2, 4]triazolo[4,3-a]pyrazine-7-
carbothioamide (13f)
Off-white powder; m.r.: 166-168 ꢀC. IR (KBr, ꢀ~/cmꢁ1): 3315
(N-H, str); 1664 (C=O, str); 1527 (C=N, str); 1143 (CF3,
str), 777 (C-Cl, str). 1H NMR (400 MHz; DMSO-d6), d,
ppm, (J, Hz): 3.96-3.99 (2H, t, J ¼ 5.2, Piperazine); 4.22-4.25 White solid; m.r.: 204-206 ꢀC. IR (KBr, ꢀ~/cmꢁ1): 3232 (N-H,
(2H, t, J ¼ 5.2, Piperazine); 4.96 (2H, s, Piperazine); 7.01- str); 1552 (C ¼ N, str); 1274 (C ¼ S, str); 1122 (CF3, str);
1
7.04 (1H, m, Ar-H); 7.27-7.31 (1H, t, J ¼ 8.0, Ar-H); 7.40-7- 1020 (C-F, str). H NMR (400 MHz; DMSO-d6), d, ppm, (J,
42 (1H, d, J ¼ 8.4, Ar-H); 7.66 (1H, s, Ar-H); 9.04 (1H, s, Hz): 4.31-4.33 (2H, t, J ¼ 5.2, Piperazine); 4.41-4.44 (2H, t,
NH). 13C NMR (100 MHz; DMSO-d6), d, ppm, (J, Hz): J ¼ 5.2, Piperazine); 5.38 (2H, s, Piperazine); 7.15-7.19 (2H,
40.03 (-CH2-CH2-); 40.9 (-CH2-CH2-); 43.25 (-CH2-); m, Ar-H); 7.31-7.34 (2H, m, Ar-H); 9.73 (1H, s, NH). 13C
117.11 (C Ar); 117.92 (d, J ¼ 268.0, -CF3); 119.09 (C Ar); NMR (100 MHz; DMSO-d6), d, ppm, (J, Hz): 42.94 (-CH2-
121.84 (C Ar); 130.04 (C Ar); 132.75 (C Ar); 141.53 (C Ar); CH2-); 44.04 (-CH2-CH2-); 44.82 (-CH2-); 114.70 (d,
142.31 (C Ar); 151.01 (C=O); 154.26 (C Ar). LC-MS m/z J ¼ 22.0, C Ar); 117.08 (d, J ¼ 268, CF3); 128.10 (d, J ¼ 9.0, C
(rel, %): 346.11 [M þ H]þ (100); 348.06 [M þ Hþþ2] (34). Ar); 136.74 (d, J ¼ 3.0, C Ar); 142.28 (d, J ¼ 38.0, C Ar);
HRMS (FAB) Calc.: C13H11ClF3N5O: 345.06042; Found: 150.95 (C Ar); 158.37 (d, J ¼ 240.0, C Ar); 182.42 (C=S).
346.0668 [M þ Hþ], 348.0628 [M þ Hþþ2].
LC-MS m/z (rel, %): 346.05 [M þ H]þ (100). HRMS (FAB)
Calc.: C13H11F4N5S: 345.06712; Found: 346.0735 [M þ Hþ].
N-(2,4-Difluorophenyl)-3-(trifluoromethyl)-5,6,7,8-
tetrahydro-[1, 2, 4]triazolo[4,3-a]pyrazine-7-
carboxamide (13d)
N-(4-bromophenyl)-3-(trifluoromethyl)-5,6,7,8-
tetrahydro-[1, 2, 4]triazolo[4,3-a]pyrazine-7-
carbothioamide (13g)
Pale brown solid; m.r.: 156-158 ꢀC. IR (KBr, ꢀ~/cmꢁ1): 3242
(N-H, str); 1645 (C=O, str); 1516 (C=N, str); 1141 (CF3, Pale brown solid; m.r.: 153-155 ꢀC. IR (KBr, ꢀ~/cmꢁ1): 3240
str); 1097 (C-F, str). 1H NMR (400 MHz; DMSO-d6), d, (N-H, str); 1528 (C ¼ N, str); 1274 (C ¼ S, str); 1159 (CF3,
ppm, (J, Hz): 3.95-3.98 (2H, t, J ¼ 5.2, Piperazine); 4.2-2- str); 783 (C-Br, str). 1H NMR (400 MHz; DMSO-d6), d,
4.25 (2H, t, J ¼ 5.2, Piperazine); 4.93 (2H, s, Piperazine); ppm, (J, Hz): 4.33-4.34 (2H, t, J ¼ 4.8, Piperazine); 4.40-4.43
7.02-7.06 (1H, m, Ar-H); 7.25-7.30 (1H, m, Ar-H); 7.38-7.44 (2H, t, J ¼ 4.8, Piperazine); 5.38 (2H, s, Piperazine); 7-28-
(1H, m, Ar-H); 8.75 (1H, s, NH). 13C NMR (100 MHz; 7.60 (4H, m, Ar-H); 9.82 (1H, s, NH). 13C NMR (100 MHz;
DMSO-d6), d, ppm, (J, Hz): 40.12 (-CH2-CH2-); 40.89 DMSO-d6), d, ppm, (J, Hz): 42.93 (-CH2-CH2-); 44.18
(-CH2-CH2-); 43.27 (-CH2-); 103.83 (C Ar); 110.77 (dd, (-CH2-CH2-); 44.99 (-CH2-); 117.10 (d, J ¼ 269.0, CF3);
J ¼ 18.0 Hz, 4.0, C, Ar); 117.11 (d, J ¼ 269.0, CF3); 123.24 (C 120.52 (C Ar); 124.49 (C Ar); 127.58 (C Ar); 128.21 (C Ar);
Ar); 128.03 (C Ar); 142.32 (C Ar); 151.02 (C=O); 154.52 (C 142.16 (C Ar); 150.91 (C Ar); 182.14 (C=S). LC-MS m/z
Ar); 156.99 (C Ar); 160.14 (C Ar). LC-MS m/z (rel, %): (rel, %): 405.97 [M-H]þ (100); 407.95 [M-H þ 2]þ (97).