HETEROCYCLES, Vol. 81, No. 8, 2010
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10.81 (s, 1H); 13C-NMR (100 MHz, DMSO-d6): 14.94, 65.16, 109.83, 114.88, 124.94, 125.26, 127.96,
128.96, 132.42, 132.81, 135.09, 135.36, 152.60, 157.04, 166.39, 168.73; MS m/z: (348)+; Anal. Calcd
for C18H16N6O2 (348.37): C 62.06, H 4.63, N 24.12. Found: C 62.30, H 4.52, N 23.95.
N-(2-Ethoxy[1,2,4]triazolo[1,5-a]quinazolin-5-yl)isonicotinichydrazide (7e): This compound obtained
o
1
as white solid with 0.244 g (70%). mp 170-173 C; IR (KBr) ν max cm-1: 1664, 3206; H-NMR (400
MHz, DMSO-d6): 1.35 (t, 3H, J = 7.50 Hz), 4.38 (q, 2H, J = 14.04 Hz), 7.51-8.48 (m, 8H), 10.42 (s,
13
1H), 10.91 (s, 1H); C-NMR (100 MHz, DMSO-d6): 14.46, 64.80, 109.30, 114.45, 122.18, 122.70,
124.92, 134.79, 147.91, 148.92, 156.25, 163.54, 168.03; MS m/z: (349)+; Anal. Calcd for C17H15N7O2
(349.35): C 58.45, H 4.33, N 28.07. Found: C 58.61, H 4.22, N 28.35.
N-(2-Benzyloxy[1,2,4]triazolo[1,5-a]quinazolin-5-yl)acetohydrazide (7f): This compound obtained as
yellow solid with 0.264 g (76%). mp 189-192 oC; IR (KBr) ν max cm-1: 1670, 3197; 1H-NMR (400 MHz,
13
DMSO-d6): 2.27 (s, 3H), 5.66 (s, 2H), 7.59-8.76 (m, 9H), 10.48 (s, 1H), 10.59 (s, 1H); C-NMR (100
MHz, DMSO-d6): 12.09, 71.67, 114.88, 115.24, 124.78, 125.21, 127.67, 128.46, 128.80, 131.16,
135.60, 136.06, 137.08, 156.68, 168.72, 169.22; MS m/z: (348)+; Anal. Calcd for C18H16N6O2 (348.37): C
62.06, H 4.63, N 24.12. Found: C 62.44, H 4.51, N 24.21.
General procedure for the synthesis of Alkyl(aralkyl)-N-(2-alkoxy[1,2,4]triazolo[1,5-a]quinazolin-5-
yl)hydrazine carboxylate (8a-d): A mixture of 2a,b (1 mmol) and benzyl carbazate or ethyl carbazate
(2.2 mmol) was refluxed in benzene (10 mL) for 2.5 h. The solvent was removed under reduced pressure,
the resulting solid was filtered off and recrystallized from MeOH.
Ethyl-N-(2-methoxy[1,2,4]triazolo[1,5-a]quinazolin-5-yl)hydrazine carboxylate (8a): This compound
obtained as white solid with 0.220 g (73%). mp 127-130 oC; IR (KBr) ν max cm-1: 1707, 3198; 1H-NMR
(400 MHz, DMSO-d6): 1.23 (t, 3H, J = 7.91 Hz), 4.00 (q, 2H, J = 10.12 Hz), 4.10 (s, 3H), 7.59-8.27
13
(m, 4H), 9.50 (s, 1H), 10.34 (s, 1H); C-NMR (100 MHz, DMSO-d6): 14.92, 57.33, 61.15, 109.71,
114.83, 124.75, 125.21, 127.07, 134.70, 135.06, 137.15, 156.69, 169.23; MS m/z: (302)+; Anal. Calcd for
C13H14N6O3 (302.29): C 51.65, H 4.67, N 27.80. Found: C 51.93, H 4.55, N 27.64.
Benzyl-N-(2-methoxy[1,2,4]triazolo[1,5-a]quinazolin-5-yl)hydrazine
carboxylate
(8b):
This
compound obtained as white solid with 0.273 g (75%). mp 197-200 oC; IR (KBr) ν max cm-1: 1718, 3215;
1H-NMR (400 MHz, DMSO-d6): 4.01 (s, 3H), 5.15 (s, 2H), 7.20-8.41 (m, 9H), 9.68 (s, 1H), 10.40 (s,
13
1H); C-NMR (100 MHz, DMSO-d6): 56.69, 66.98, 109.67, 114.85, 124.75, 125.25, 126.25, 128.54,
128.81, 135.11, 135.33, 136.98, 152.74, 157.10, 168.42; MS m/z: (364)+; Anal. Calcd for C18H16N6O3
(364.37): C 59.34, H 4.43, N 23.06. Found: C 59.16, H 4.33, N 22.85.