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A. Mobinikhaledi et al.: Synthesis of novel bis-1,2,4-triazoles and bis-1,3,4-thiadiazolesꢀ
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Calcd for C12H16N6O2S2: C, 42.34; H, 4.74; N, 24.69; S, 18.84. Found: C,
Terephthalohydrazide (2a)ꢀYield 92%; mp > 300°C; IR: 3300 and
3230 (NH, NH2), 3030 (CH-aromatic), 1714 cm-1 (C=O); 1H NMR: δ 4.50 42.17; H, 4.89; N, 24.51; S, 18.79.
(bs, 4H, 2NH2, exchangeable with D2O), 7.87 (s, 4H, Ar-H), 9.90 (s, 2H,
2NH, exchangeable with D2O); 13C NMR: 127.4 (CH), 135.9 (CH), 165.6 Isophthaloyl bis(N-ethylhydrazino-2-thiocarbamide) (3e)ꢀYield
(CO). Anal. Calcd for C8H10N4O2: C, 49.48; H, 5.19; N, 28.85. Found: C, 92%; mp 207–209°C; IR: 3311–3180 (NH), 2974 (CH-Ar), 2931 (CH3), 1676
(C=O), 1242 cm-1 (C=S); 1H NMR: δ 1.06 (t, 6H, 2CH3, J = 7 Hz), 3.45–3.50
(q, 4H, 2CH2, J = 7 Hz), 8.08–8.43 (m, 4H, Ar-H), 8.11 (s, 2H, NH, ex-
changeable with D2O), 9.28 (s, 2H, NH, exchangeable with D2O), 10.41
(s, 2H, NH, exchangeable with D2O); 13C NMR: δ 14.9, 39.0, 128.2, 128.6,
131.3, 133.2, 165.9, 181.9. Anal. Calcd for C14H20N6O2S2: C, 45.63; H, 5.47;
N, 22.81; S, 17.40. Found: C, 45.47; H, 5.58; N, 22.67; S, 17.32.
49.68; 5.01; N, 28.59.
Isophthalohydrazide (2b)ꢀYield 91%; mp 232–234°C; IR: 3296 and
1
3220 (NH, NH2), 1678 cm-1 (C=O); H NMR: δ 4.53 (bs, 4H, 2NH2, ex-
changeable with D2O), 7.49–7.54 (q, 1H, Ar-H), 7.90, 7.92 (d, 2H, Ar-H),
8.25 (s, 1H, Ar-H), 9.82 (s, 2H, 2NH, exchangeable with D2O); 13C NMR:
δ 126.5 (CH), 128.9 (CH), 129.7 (CH), 134.0 (CH), 165.9 (CO). Anal. Calcd
for C8H10N4O2: C, 49.48; H, 5.19; N, 28.85. Found: C, 49.27; H, 5.41; N,
28.98.
Isophthaloyl bis(N-phenylhydrazino-2-thiocarbamide) (3f)ꢀ
Yield 89%; mp 191–192°C; IR: 3184–3113 (NH), 2939 (CH-Ar), 1676
1
(C=O), 1207 cm-1 (C=S); H NMR: δ 7.15–8.21 (m, 14H, Ar-H), 8.58 (s,
2H, NH, exchangeable with D2O), 9.94 (s, 2H, NH, exchangeable
with D2O), 10.68 (s, 2H, NH, exchangeable with D2O); 13C NMR: δ
125.7, 126.5, 128.6, 129.5, 131.5, 133.2, 139.6, 166.1, 181.9. Anal. Calcd for
C22H20N6O2S2: C, 56.88; H, 4.34; N, 18.09; S, 13.80. Found: C, 56.92; H,
4.47; N, 17.89; S, 13.71.
General procedure for the synthesis
of bis-terephthaloyl and isophthaloyl
thiosemicarbazides 3a–f
A mixture of 2a or 2b (1.95 g, 10 mmol) and methyl, ethyl or phenyl
isothiocyanate (20 mmol) in absolute ethanol (50 mL) was heated un-
der reflux for 7 h. The mixture was cooled and filtered. The obtained
precipitate was crystallized from DMF-H2O (2:1) to afford the corre-
sponding bis-thiosemicarbazide derivative 3a–f.
General method for the synthesis
of bis(1,2,4-triazole-3-thiols) 4a–f
A suspension of 3a–f (2 mmol) in ethanol (25 mL) was dissolved in
aqueous sodium hydroxide (2 N, 2 mL) and the solution was heated
under reflux for 4 h. Then, the solution was concentrated, cooled,
and filtered. The filtrate was adjusted to pH ~4–5 with hydrochloric
acid and kept at room temperature for 1 h. The obtained product was
filtered, washed with water, dried, and crystallized from DMF-H2O.
Terephthaloyl bis(N-methylhydrazino-2-thiocarbamide) (3a)ꢀ
Yield 94%; mp 235–237°C; IR: 3252 and 3203 (NH), 2980 (CH-Ar),
1
2939 (CH3), 1676 (C=O), 1251 cm-1 (C=S); H NMR: 2.88 (s, 6H, 2CH3),
8.00 (s, 4H, Ar-H), 8.10 (s, 2H, NH-NH, exchangeable with D2O), 9.37
(s, 2H, NH, exchangeable with D2O), 10.47 (s, 2H, NH, exchangeable
with D2O); 13C NMR: δ 31.4, 128.2, 135.7, 165.9, 182.7. Anal. Calcd for
C12H16N6O2S2: C, 42.34; H, 4.74; N, 24.69; S, 18.84. Found: C, 42.21; H,
4.89; N, 24.50; S, 18.74.
5,5′-(1,4-Phenylene)-bis(4-methyl-4H-1,2,4-triazole-3-thiol) (4a)ꢀ
Yield 88%; mp > 300°C; IR: 3111 (NH), 3032 (CH-Ar), 2933 (CH3), 2756
(S-H), 1564, 1520 (C=N), 1275 cm-1 (C=S); 1H NMR: δ 3.56 (s, 6H, 2CH3),
7.93 (s, 4H, Ar-H), 14.04 (s, 2H, SH, exchangeable with D2O); 13C NMR:
δ 32.2, 128.5, 129.5, 151.1, 168.2. Anal. Calcd for C12H12N6S2: C, 47.35; H,
3.97; N, 27.61; S, 21.07. Found: C, 47.21; H, 3.71; N, 27.51; S, 20.86.
Terephthaloyl bis(N-ethylhydrazino-2-thiocarbamide) (3b)ꢀ
Yield 95%; mp 233–234°C; IR: 3319–3240 (NH), 2970 (CH-Ar), 2931
(CH3), 1680 (C=O), 1246 cm-1 (C=S); 1H NMR: δ 1.07 (t, 6H, 2CH3, J = 7
Hz), 3.48 (q, 4H, 2CH2, J = 7 Hz), 8.00 (s, 4H, Ar-H), 8.14 (s, 2H, NH, ex-
changeable with D2O), 9.26 (s, 2H, NH, exchangeable with D2O), 10.44
(s, 2H, NH, exchangeable with D2O); 13C NMR: δ 14.9, 39.0, 128.2, 135.8,
165.8, 181.9. Anal. Calcd for C14H20N6O2S2: C, 45.63; H, 5.47; N, 22.81; S,
17.40. Found: C, 45.46; H, 5.53; N, 22.74; S, 17.29.
5,5′-(1,4-Phenylene)bis(4-ethyl-4H-1,2,4-triazole-3-thiol)ꢀ(4b)ꢀ
Yield 89%; mp > 300°C; IR: 3111 (NH), 3032 (CH-Ar), 2986, 2933 (CH3),
1
2750 (S-H), 1566, 1518 (C=N), 1269 cm-1 (C=S); H NMR: δ 1.18 (t, 6H,
2CH3, J = 7 Hz), 4.08 (q, 4H, 2CH2, J = 7 Hz), 7.88 (s, 4H, Ar-H), 13.95
(s, 2H, SH, exchangeable with D2O); 13C NMR: δ 13.9, 39.2, 128.6, 128.6,
150.7, 167.7. Anal. Calcd for C14H16N6S2: C, 50.58; H, 4.85; N, 25.28; S,
19.29. Found: C, 50.41; H, 5.08; N, 25.31; S, 19.43.
Terephthaloyl bis(N-phenylhydrazino-2-thiocarbamide) (3c)ꢀ
Yield 96%; mp 221–223°C; IR: 3259–3175 (NH), 2928 (CH-Ar), 1672
1
(C=O), 1253 cm-1 (C=S); H NMR: δ 7.14–8.05 (m, 14H, Ar-H), 9.73 (s,
5,5′-(1,4-Phenylene)bis(4-phenyl-4H-1,2,4-triazole-3-thiol) (4c)ꢀ
Yield 89%; mp > 300°C; IR: 3065 (NH), 2976 (CH-Ar), 2914, 2746 (S-H),
1595, 1498 (C=N), 1273 cm-1 (C=S); 1H NMR: δ 7.03–7.46 (m, 14H, Ar-H),
14.11 (s, 2H, SH, exchangeable with D2O); 13C NMR: δ 126.7, 128.7, 129.3,
129.8, 130.4, 134.5, 151.3, 169.4. Anal. Calcd for C22H16N6S2: C, 61.66; H,
3.76; N, 19.61; S, 14.97. Found: C, 61.48; H, 3.89; N, 19.49; S, 15.15.
2H, NH, exchangeable with D2O), 9.86 (s, 2H, NH, exchangeable with
D2O), 10.68 (s, 2H, NH, exchangeable with D2O); 13C NMR: δ 125.6,
126.6, 128.3, 128.5, 135.8, 139.7, 162.8, 165.9, 181.6. Anal. Calcd for
C22H20N6O2S2: C, 56.88; H, 4.34; N, 18.09; S, 13.80. Found: C, 56.71; H,
4.39; N, 17.95; S, 13.88.
Isophthaloyl bis(N-methylhydrazino-2-thiocarbamide) (3d)ꢀ
Yield 90%; mp 197–199°C; IR: 3302 and 3203 (NH), 3005 (CH-Ar),
2939 (CH3), 1683 (C=O), 1253 cm-1 (C=S); 1H NMR: δ 2.88 (s, 6H, 2CH3),
7.57–8.01(m, 4H, Ar-H), 8.42 (s, 2H, NH, exchangeable with D2O), 9.35
5,5′-(1,3-Phenylene)bis(4-methyl-4H-1,2,4-triazole-3-thiol) (4d)ꢀ
Yield 86%; mp 290–292°C; IR: 3109 (NH), 3047 (CH-Ar), 2914 (CH3),
1
2769 (S-H), 1539, 1500 (C=N), 1275 cm-1 (C=S); H NMR: δ 3.56 (s, 6H,
(s, 2H, NH, exchangeable with D2O), 10.43 (s, 2H, NH, exchangeable 2CH3), 7.93 (s, 4H, Ar-H), 14.04 (s, 2H, SH, exchangeable with D2O);
with D2O); 13C NMR: δ 31.4, 128.2, 130.6, 131.3, 133.2, 166.0, 182.8. Anal. 13C NMR: δ 32.2, 128.5, 129.5, 151.1, 168.2. Anal. Calcd for C12H12N6S2:
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