8
of 11
GEORGE ET AL.
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1
1
51.9 (aromatic carbons), 155.1 (C=O), 160.9 (C=O), 164.9 (C=S); MS
1698 (C=O), 1653 (C=O), 1135 (C=S); H NMR (DMSO‐d
δ, ppm): 7.14–7.18 (m, 1H, Ar–H), 8.47 (s, 1H, C –H), 7.34 (t, 2H,
J = 7.80 Hz, Ar–H), 7.55 (d, 2H, J = 7.60 Hz, Ar–H), 8.77 (s, 1H, C –H),
9.69 (s, 2H, 2NH, exchangeable with D O), 9.89 (s, 2H, NH,
O); C NMR (DMSO‐d , 100 MHz, δ, ppm):
6
, 400 MHz,
+
(m/z, %): 253.55 (M , 22.85), 54.16 (100); elemental analysis
2
calculated for C
7 7
H N
7 2
O S; C, 33.20; H, 2.79; N, 38.27; found C,
5
33.52; H, 2.86; N, 39.01.
2
1
3
exchangeable with D
2
6
2
‐(2‐Methyl‐7‐oxo‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidine‐6‐
117.3, 125.6, 128.6, 128.9, 139.6, 148.3, 151.9, 152.5 (aromatic
carbons), 156.7 (C=O), 160.6 (C=O), 181.0 (C=S); elemental analysis
carbonyl)hydrazine carbothioamide (6b)
White powder; yield 78%; m.p. 191–192°C; FT‐IR (KBr) (ʋmax/cm ):
455, 3377 (NH ), 3379 (NH), 3298 (NH), 3291 (NH), 3085 (CH
−1
11 7 2
calculated for C13H N O S; C, 47.41; H, 3.37; N, 29.77; found C,
3
2
47.59; H, 3.42; N, 29.98.
aromatic), 2878 (CH aliphatic), 1693 (C=O), 1668 (C=O), 1144 (C=S);
1
H NMR (DMSO‐d
6
, 400 MHz, δ, ppm): 2.25 (s, 3H, CH
O), 7.47 (s, 1H, NH, exchangeable with
O), 7.56 (s, 1H, NH, exchangeable with D O), 8.60 (s, 1H, C –H),
0.56 (s, 2H, NH , exchangeable with D O); C NMR (DMSO‐d
00 MHz, δ, ppm): 13.9 (CH ), 147.9, 150.6, 151.3, 155.7 (aromatic
3
), 7.34 (s, 1H,
2‐(2‐Methyl‐7‐oxo‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidine‐6‐
carbonyl)‐phenylhydrazine carbothioamide (6f)
O=C–NH, exchangeable with D
2
−
1
D
2
2
5
Pale yellow powder; yield 53%; m.p. 174–176°C; FT‐IR (KBr) (ʋmax/cm ):
13
1
1
2
2
6
,
3435 (NH), 3382 (NH), 3315 (NH), 3306 (NH), 3060 (CH aromatic),
3
2936 (H, O=C–NH, exchangeable with D
8.68 (s, 1H, C –H), 9.88 (s, 2H, S=C–NH, NH, exchangeable with D
10.40 (s, 1H, NH, exchangeable with D
100 MHz, δ, ppm): 14.6 (CH ), 121.5, 125.3, 126.3, 128.5, 129.3, 139.6,
49.7, 151.5, 154.6 (aromatic carbons), 156.2 (C=O), 164.4 (C=O), 181.7
(C=S); elemental analysis calculated for C14 S; C, 48.97; H, 3.82;
N, 28.55; found C, 49.14; H, 3.80; N, 28.78.
2
O), 7.17–7.65 (m, 5H, Ar–H),
O),
O); C NMR (DMSO‐d
carbons), 159.5 (C=O), 161.1 (C=O), 165.1 (C=S); MS (m/z, %): 267.28
5
2
+
13
(M , 47.16), 146.78 (100); elemental analysis calculated for C
8
9 7 2
H N O S;
2
6
,
C, 35.95; H, 3.39; N, 36.68; found C, 36.18; H, 3.28; N, 37.01.
3
1
N‐Ethyl‐2‐(7‐oxo‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidine‐6‐
carbonyl)hydrazine carbothioamide (6c)
13 7 2
H N O
−1
White powder; yield 60%; m.p. 175–177°C; FT‐IR (KBr) (ʋmax/cm ):
3
395 (NH), 3358 (NH), 3288 (NH), 3282 (NH), 3080 (CH aromatic),
N‐(3‐Chlorophenyl)−2‐(7‐oxo‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyr‐
imidine‐6‐carbonyl)hydrazine carbothioamide (6g)
1
2890 (CH aliphatic), 1684 (C=O), 1654 (C=O), 1134 (C=S); H NMR
−
1
(DMSO‐d
6
, 400 MHz, δ, ppm): 1.08–1.09 (m, 3H, CH
CH ), 7.81 (s, 1H, O=C–NH, exchangeable with D
O), 8.11 (s, 1H, C –H), 8.66 (s, 1H, C
, exchangeable with D O), 10.22 (br s, H, NH,
O); C NMR (DMSO‐d , 100 MHz, δ, ppm): 14.8
), 153.5, 154.1, 155.5 (aromatic carbons), 157.9 (C=O),
65.5 (C=O), 182.3 (C=S); elemental analysis calculated for C S;
C, 38.43; H, 3.94; N, 34.86; found C, 38.72; H, 4.01; N, 35.11.
2
CH
3
), 3.27–3.31 (m,
O), 7.91 (s, H,
–H), 9.15
White powder; yield 44%; m.p. 169–171°C; FT‐IR (KBr) (ʋmax/cm ):
2H, CH
2
3
2
3427 (NH), 3374 (NH), 3275 (NH), 3260 (NH), 3090 (CH aromatic), 1674
1
NH, exchangeable with D
s, 1H, NH–C
exchangeable with D
CH ), 38.1 (CH
2
5
2
(C=O), 1130 (C=S); H NMR (DMSO‐d
6
, 400 MHz, δ, ppm): 7.26 (s, 1H,
O), 7.35–7.79 (m, 6H, C ‐H + C
H + 4Ar–H), 8.18 (s, 1H, NH, exchangeable with D O), 9.21 (s, 1H,
S=C–NH, exchangeable with D O), 9.91 (s, 1H, Ph–NH, exchangeable
with D O); elemental analysis calculated for C13 10ClN S; C, 42.92; H,
2.77; N, 26.95; found C, 43.25; H, 2.94; N, 27.21.
(
2
H
5
2
O=C–NH, exchangeable with D
2
5
2
‐
13
2
6
2
(
3
2
2
1
9 11
H
N
7
O
2
2
H
7 2
O
N‐Ethyl‐2‐(2‐methyl‐7‐oxo‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimi-
dine‐6‐carbonyl)hydrazine carbothioamide (6d)
N‐(4‐Bromophenyl)‐2‐(7‐oxo‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyr‐
imidine‐6‐carbonyl)hydrazine carbothioamide (6h)
−
1
−1
White powder; yield 78%; m.p. 197–199°C; FT‐IR (KBr) (ʋmax/cm ):
White powder; yield 50%; m.p. 175–177°C; FT‐IR (KBr) (ʋmax/cm ):
3
2
413 (NH), 3351 (NH), 3295 (NH), 3262 (NH), 3095 (CH aromatic),
3440 (NH), 3378 (NH), 3285 (NH), 3282 (NH), 3092 (CH aromatic),
1
1
895 (CH aliphatic), 1693 (C=O), 1669 (C=O), 1159 (C=S); H NMR
1683 (C=O), 1662 (C=O), 1135 (C = S); H NMR (DMSO‐d
6
, 400 MHz,
O), 7.42 (d, 2H,
J = 7.60 Hz, Ar–H), 7.86 (d, 2H, J = 7.92 Hz, Ar–H), 7.92–7.93 (m, 2H,
–H + C –H), 8.20 (s, 1H, NH, exchangeable with D O), 9.53 (s, 1H,
O), 10.01 (s, 1H, Ph–NH, exchangeable
, 100 MHz, δ, ppm): 122.1, 123.5, 124.1,
(
DMSO‐d
6
, 400 MHz, δ, ppm): 1.06 (t, 3H, J = 7.20 Hz, CH
), 3.46 (q, 2H, J = 7.20 Hz, CH CH ), 7.91 (s, 1H, O=C–NH,
O), 8.00 (s, 1H, NH, exchangeable with D
–H), 9.15 (s, 1H, NH–C , exchangeable with D
0.41 (s, 1H, S=C–NH, exchangeable with D
00 MHz, δ, ppm): 14.6 (CH ), 19.2 (CH ), 34.5 (CH
2
CH
3
), 2.41
δ, ppm): 7.30 (s, 1H, O=C–NH, exchangeable with D
2
(s, 3H, CH
3
2
3
exchangeable with D
2
2
O),
O),
C
5
2
2
8
1
1
1
.66 (s, 1H, C
5
2
H
5
2
S=C–NH, exchangeable with D
2
1
3
13
2
O); C NMR (DMSO‐d
6
,
with D
2
O); C NMR (DMSO‐d
6
3
3
2
), 150.9, 153.5,
124.9, 125.0, 125.4, 138.3, 139.1 (aromatic carbons), 160.0 (C=O),
+
+
56.5 (aromatic carbons), 160.5 (C=O), 160.7 (C=O), 182.4 (C=S); MS
161.1 (C=O), 180.1 (C=S); MS (m/z, %): 406.0 (M , 11.35), 408 (M + 2,
6.22), 68.27 (100); elemental analysis calculated for C13 10BrN S; C,
38.25; H, 2.47; N, 24.02; found C, 38.28; H, 2.49; N, 24.06.
+
(m/z, %): 295.06 (M , 17.43), 86.84 (100); elemental analysis
H
7 2
O
13 7 2
calculated for C10H N O S; C, 40.67; H, 4.44; N, 33.20; found C,
40.91; H, 4.50; N, 33.48.
4
.1.6 | General procedure for the synthesis of 7a–h
2
‐(7‐Oxo‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidine‐6‐carbonyl)‐N‐
phenylhydrazine carbothioamide (6e)
White powder; yield 60%; m.p. 161–163°C; FT‐IR (KBr) (ʋmax/cm ):
420 (NH), 3375 (NH), 3305 (NH), 3292 (NH), 3089 (CH aromatic),
The appropriate thiosemicarbazide 6a–h (0.01 mol) was dissolved in
6% aqueous sodium hydroxide solution (20 ml) and refluxed for 4 hr.
The resulting solution was cooled, filtered, and acidified with dilute
−
1
3