V. Jatav et al. / European Journal of Medicinal Chemistry 43 (2008) 135e141
139
Step-2: synthesis of 2-amino-5-aryl 103040-thiadiazoles
4e
IR (cmꢀ1) 1700 (C]O), 1614 (C]C) Alkene, 1555 (C]N), 1326
(CN), 760 (CS); 13C NMR (d) 160.2 (C-2), 168.8 (C-4), 112 (C-11),
136 (C-12), 137.9 (C-100), 134 (C-13); 1H NMR (300 MHz, d) 5.12 (d,
1H, olefinic CH, J ¼ 15.4 Hz), 6.41e7.49 (a set of signals, 13H,
aromatic protons and olefinic CH).
Thiosemicarbazone III (0.05 M) was suspended in 300 ml
warm water, FeCl3 (0.15 M) in 300 ml water was added quan-
titatively, slowly with constant stirring. The contents were
heated at 80e90 ꢁC for 45 min. Solution was filtered hot
and then citric acid (0.11 M) and sodium citrate (0.05 M)
were added. The resulting mixture was divided into 4 parts
and each part was neutralized separately with ammonia
(10%). The required amine separated out, filtered with suction,
dried and recrystallised with appropriate solvent. Physico-
chemical properties are reported in Table 6.
4f
IR (cmꢀ1) 1737 (C]O), 1610 (C]C) Alkene, 1532 (C]N), 1269
(CN), 733 (CS); 13C NMR (d) 167 (C-2), 168.9 (C-4), 112 (C-4), 136
(C-12), 134 (C-100), 134 (C-13), 125 (CA), 130 (CB); 1H NMR
(300 MHz, d) 5.60 (d, 1H, olefinic CH, J ¼ 15.6 Hz), 6.99 (d, 2H,
olefinic CH), 6.78e8.01 (a set of signals, 14H, aromatic protons and
olefinic CH).
IR (cmꢀ1) 1700 (C]O), 1620 (C]C) Alkene, 1542 (C]N), 1274 (CN),
740 (CS); 13C NMR(d) 158.8 (C-2), 168.6 (C-4), 112 (C-11), 136(C-12),
136.5 (C-100), 134.5 (C-13), 56 (CA); 1H NMR (300 MHz, d) 3.84 (s, 3H,
CH3), 5.82 (d, 1H, olefinic CH, J ¼ 14.4 Hz), 6.72e7.94 (a set of signals,
13H, aromatic protons and olefinic CH).
IR (cmꢀ1) 1739 (C]O), 1642 (C]C) Alkene, 1542 (C]N), 1334
(CN), 759 (CS); 13C NMR (d) 167 (C-2), 168.6 (C-4), 112 (C-11), 136
(C-12), 128.8 (C-100), 131.4 (C-13), 55.5 (CA), 56 (CB); 1H NMR
(300 MHz, d) 3.63 (s, 3H, CH3), 3.72 (s, 3H, CH3), 5.76 (d, 1H,
olefinic CH, J ¼ 15.0 Hz), 6.60e7.86 (a set of signals, 12H, aromatic
protons and olefinic CH).
IR (cmꢀ1) 1701 (C]O), 1637 (C]C) Alkene, 1530 (C]N), 1267
(CN), 774 (CS); 13C NMR (d) 165 (C-2), 168 (C-4), 112 (C-11), 136
(C-12), 133.5 (C-100), 131.4 (C-13), 21.4 (CA), 56 (CB); 1H NMR
(300 MHz, d) 2.32 (s, 3H, CH3), 3.74 (s, 3H, CH3), 5.85 (d, 1H,
olefinic CH, J ¼ 15.2 Hz), 6.74e7.10 (a set of signals, 12H, aromatic
protons and olefinic CH).
4g
4h
5.1.2. Synthesis of 2-methyl-3-(103040-thiadiazole-20-yl)-
4(3H )-quinazolinone[21]
Anthranilic acid 1 (0.01 M) and acetic anhydride were re-
fluxed under anhydrous condition for 4 h. Excess of acetic an-
hydride was distilled off under reduced pressure. To the
mixture obtained, amines IV (0.01 M) in glacial acetic acid
was added and refluxed for 4 h. Obtained reaction mixture
was poured into crushed ice and left overnight. The solid
which separated out was filtered, washed thoroughly with
cold distilled water, dried and recrystallised from hot ethanol.
The yield, melting point and other physical properties of syn-
thesized compound are recorded in Table 7.
4i
4j
IR (cmꢀ1) 1734 (C]O), 1634 (C]C) Alkene, 1542 (C]N), 1293
(CN), 658 (CS); 13C NMR (d) 167 (C-2), 168.7 (C-4), 112 (C-11),
135.8 (C-12), 134.6 (C-100), 131.4 (C-13), 56 (CA); 1H NMR
(300 MHz, d) 3.80 (s, 3H, CH3), 5.62 (d, 1H, olefinic CH,
J ¼ 15.6 Hz), 6.51e7.89 (a set of signals, 12H, aromatic protons
and olefinic CH).
5.1.3. Synthesis of title compound
The title compounds were synthesized by following the
procedure reported earlier [11,22e26]. A solution of 3
(0.01 M) and opportune benzaldehyde (0.01 M) were reacted
with glacial acetic acid (10 ml) and refluxed for 12 h.
4k
4l
IR (cmꢀ1) 1700 (C]O), 1630 (C]C) Alkene, 1560 (C]N), 1348
(CN), 591 (CS); 13C NMR (d) 165 (C-2), 168.6 (C-4), 112 (C-11), 136
(C-12), 137.9 (C-100), 131.6 (C-13), 56 (CA); 1H NMR (300 MHz, d)
3.46 (s, 3H, CH3), 5.43 (d, 1H, olefinic CH, J ¼ 15.4 Hz), 6.65e7.96 (a
set of signals, 12H, aromatic protons and olefinic CH).
The solid
4 which separated out was filtered with
IR (cmꢀ1) 1708 (C]O), 1608 (C]C) Alkene, 1505 (C]N), 1278
(CN), 620 (CS); 13C NMR (d) 167 (C-2), 168 (C-4), 112 (C-11), 136.5
(C-12), 134.9 (C-100), 131.6 (C-13), 124.2 (CA), 129.2 (CB), 56 (CC);
1H NMR (300 MHz, d) 3.57 (s, 3H, CH3), 5.66 (d, 1H, olefinic CH,
J ¼ 15.2 Hz), 7.01 (d, 2H, olefinic CH), 6.72e8.12 (a set of signals,
13H, aromatic protons and olefinic CH).
suction and recrystallised from dimethylformamide to
give pure compound. The physical data of the styryl quinazo-
linone are given in Table 1. The IR spectra, 13C NMR spectra
1
and H NMR spectra of the title compounds are as follows:
4m
4n
IR (cmꢀ1) 1701 (C]O), 1693 (C]C) Alkene, 1562 (C]N), 1274
(CN), 761 (CS); 13C NMR (d) 164 (C-2), 165 (C-4), 112 (C-11), 136
1
(C-12), 136.5 (C-100), 131.9 (C-13), 20.9 (CA); H NMR (300 MHz, d)
4a
4b
IR (cmꢀ1) 1693 (C]O), 1650 (C]C) Alkene, 1530 (C]N), 1317
(CN), 688 (CS); 13C NMR (300 MHz, d) 168 (C-4), 162.4 (C-2), 112
2.36 (s, 3H, CH3), 5.60 (d, 1H, olefinic CH, J ¼ 15.2 Hz), 6.66e7.90
(a set of signals, 13H, aromatic protons and olefinic CH).
IR (cmꢀ1) 1703 (C]O), 1609 (C]C) Alkene, 1559 (C]N), 1251
(CN), 615 (CS); 13C NMR (d) 161.4 (C-2), 168 (C-4), 112 (C-11), 136
(C-12), 128.5 (C-100), 131.9 (C-13), 55.4 (CA), 22 (CB); 1H NMR
(300 MHz, d) 2.30 (s, 3H, CH3), 3.74 (s, 3H, CH3), 5.64 (d, 1H,
olefinic CH, J ¼ 15.2 Hz), 6.68e7.89 (a set of signals, 12H, aromatic
protons and olefinic CH).
IR (cmꢀ1) 1612 (C]O), 1650 (C]C) Alkene, 1520 (C]N), 1313
(CN), 615 (CS); 13C NMR (d) 165 (C-2), 168 (C-4), 112 (C-11), 136
(C-12), 134.6 (C-100), 131.4 (C-13), 50.5 (CA), 20.9 (CB); 1H NMR
(300 MHz, d) 2.30 (s, 3H, CH3), 2.34 (s, 3H, CH3), 5.58 (d, 1H,
olefinic CH, J ¼ 15.4 Hz), 6.87e8.10 (a set of signals, 12H, aromatic
protons and olefinic CH).
IR (cmꢀ1) 1693 (C]O), 1610 (C]C) Alkene, 1590 (C]N), 1316
(CN), 667 (CS); 13C NMR (d) 158.6 (C-2), 168.7 (C-4), 112 (C-11),
136 (C-12), 135.1 (C-100), 131.6 (C-13), 22.4 (CA), 131.9 (CB); 1H
NMR (300 MHz, d) 2.40 (s, 3H, CH3), 5.76 (d, 1H, olefinic CH,
J ¼ 15.2 Hz), 6.54e7.94 (a set of signals, 12H, aromatic protons and
olefinic CH).
1
(C-11), 136 (C-12), 136.5 (C-100), 135 (C-18); H NMR (300 MHz, d)
5.16 (d, 1H, olefinic CH, J ¼ 15.2 Hz), 6.6e7.92 (a set of signals, 14H,
aromatic protons and olefinic CH).
IR (cmꢀ1) 1700 (C]O), 1611 (C]C) Alkene, 1520 (C]N), 1313
(CN), 675 (CS); 13C NMR (300 MHz, d) 161 (C-2), 161.5 (C-4), 114.7
(C-11), 136 (C-12), 136.5 (C-100), 134 (C-13), 55.4 (CA); 1H NMR
(300 MHz, d) 3.73 (s, 3H, CH3), 5.74 (d, 1H, olefinic CH,
J ¼ 15.5 Hz), 6.83e8.00 (a set of signals, 13H, aromatic protons and
olefinic CH).
4o
4p
4c
IR (cmꢀ1) 1691 (C]O), 1640 (C]C) Alkene, 1530 (C]N), 1275
(CN), 773 (CS); 13C NMR (d) 165 (C-2), 168 (C-4), 112 (C-11), 136
(C-12), 133.5 (C-100), 134.9 (C-13), 21.4 (CA); 1H NMR (300 MHz, d)
2.35 (s, 3H, CH3), 5.84 (d, 1H, olefinic CH, J ¼ 15.2 Hz), 6.12e7.85 (a
set of signals, 13H, aromatic protons and olefinic CH).
IR (cmꢀ1) 1700 (C]O), 1668 (C]C) Alkene, 1591 (C]N), 1326
(CN), 752 (CS); 13C NMR (d) 165 (C-2), 168 (C-4), 112 (C-11), 136.4
(C-12), 134.6 (C-100), 135 (C-13); 1H NMR (300 MHz, d) 5.52 (d, 1H,
olefinic CH, J ¼ 15.2 Hz), 6.80e7.48 (a set of signals, 13H, aromatic
protons and olefinic CH).
4d