HETEROCYCLES, Vol. 87, No. 4, 2013
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378 (22.4), 348 (5.5), 290 (21.2), 275 (11.8), 261 (100), 244 (20.2), 217 (63.5), 183 (42.1), 155 (39.1),
137 (43.1), 77 (42.6); Anal. Calcd for C19H24N2O5S (%): C, 58.15; H, 6.16; N, 7.14. Found C, 58.20; H,
6.14; N, 7.18%.
Diethyl 3-hydroxy-6-(p-methoxyphenyl)-8-methyl-1,6-dihydro-2H-pyrimido[2,1-c][1,2,4]triazine-
4,7-dicarboxylate (5). A mixture of compound 3 (0.392 g, 0.001 mol) and ethyl carbazate (0.104 g, 0.001
mol) in EtOH (10 mL) and few drops of piperidine was refluxed for 2 h. The solid thus obtained was
filtered off and recrystallized from EtOH to give compound 5 as yellow crystals (0.274 g, yield 70%): mp
248-250 °C; IR (ν cm-1) 3243 (NH), 3113 (CH aromatic), 2979, 2955 (CH aliphatic), 1704, 1648 (C=O),
1
1612 (C=N); H NMR (DMSO-d6) δ 1.09 (t, 6H, CH2CH3, J = 6.6 Hz), 2.23 (s, 3H, CH3), 3.71 (s, 3H,
OCH3), 3.99 (q, 4H, CH2CH3, J = 6.9 Hz), 5.08 (s, 1H, pyrimidine-H-6), 6.85 (d, 2H, ArH’s, J = 8.1 Hz),
7.12 (d, 2H, ArH’s, J =9 Hz), 6.88, 7.15 (s, 2H, D2O-exchangeable, NH), 9.13 (s, 1H, D2O-exchangeable,
OH); MS m/z (%): [M+] 416 (34.3), 415 (32.5), 403 (32.5), 373 (38.5), 340 (34.3), 308 (36.7), 284 (51.5),
274 (42), 183 (45), 137 (100), 84 (88.7), 58 (52.6); Anal. Calcd for C20H24N4O6 (%): C, 57.68; H, 5.81;
N, 13.45. Found C, 57.70; H, 5.80; N, 13.50%.
6-(p-Methoxyphenyl)-8-methyl-3-oxo-1,3,4,6-tetrahydro-2H-pyrimido[2,1-c][1,2,4]triazine-7-carbo-
hydrazide (7). A suspension of compound 3 (0.392 g, 0.001 mol) and hydrazine hydrate (4 mL, 99%) in
EtOH (10 mL) was refluxed for 2 h and cooled. The solid separated was filtered off and recrystallized
from dioxane to give compound 7 as yellow crystals (0.274 g, yield 70%): mp 258-260 °C; IR (ν cm-1)
1
3431, 3250 (NH2, NH), 3050 (CH aromatic), 2925 (CH aliphatic), 1632 (C=O); H NMR (DMSO-d6) δ
2.28 (s, 3H, CH3), 3.39 (brs, 2H, D2O-exchangeable, NH2), 3.77 (s, 3H, OCH3), 3.79 (s, 2H, CH2), 6.82
(s, 1H, pyrimidine-H-6), 7.03 (d, 2H, ArH’s, J = 8.7 Hz), 7.79 (d, 2H, ArH’s, J = 8.7 Hz), 7.65, 7.81, 7.82
(s, 3H, D2O-exchangeable, NH); MS m/z (%): [M+] 330 (55.3), [M++1] 331 (82.9), 302 (61.7), 286 (61.7),
274 (15), 252 (70.2), 206 (61.7), 172 (74.5), 92 (100), 78 (80), 58 (46.8); Anal. Calcd for C15H18N6O3
(%): C, 54.54; H, 5.49; N, 25.44. Found C, 54.60; H, 5.50; N, 25.40%.
2-Hydrazino-6-(p-methoxyphenyl)-4-methyl-1,6-dihydropyrimidine-5-carbohydrazide (8).
A mixture of compound 2 (0.392 g, 0.001 mol) and hydrazine hydrate (5 mL, 99%) was heated under
reflux for 2 h. The reaction mixture was cooled and poured gradually onto crushed ice. The solid obtained
was filtered off and recrystallized from EtOH to give compound 8 as yellow crystals (0.31 g, yield 80%):
mp 168-170 °C; IR (ν cm-1) 3243, 3139 (NH2, NH), 3034 (CH aromatic), 2981 (CH aliphatic), 1625
1
(C=O), 1602 (C=N); H NMR (DMSO-d6) δ 2.24 (s, 3H, CH3), 3.69 (s, 3H, OCH3), 4.71 (s, 4H, D2O-
exchangeable, NH2), 6.83 (s, 1H, pyrimidine-H-6), 7.02 (d, 2H, ArH’s, J = 8.4 Hz), 7.56 (s, 1H, D2O-
exchangeable, NH), 7.59 (s, 1H, D2O-exchangeable, NH), 7.77 (d, 2H, ArH’s, J = 8.4 Hz), 8.20 (s, 1H,
D2O-exchangeable, NH); MS m/z (%): [M++1] 291 (16.1), [M+] 290 (17.8), 275 (19.2), 264 (20.9), 234
(25.1), 219 (21.4), 172 (24.2), 135 (29.9), 134 (22), 75 (100), 60 (9.6), 52(8.4); Anal. Calcd for