M. Rafiq et al.
(Z)-3-(2-Methoxybenzyl)-4-[(2-
phenylethylidene)amino]-1H-1,2,4-triazole-5(4H)-
thione (6d)
(Z)-3-(2-bromobenzyl)-4-[(thiophen-2-
ylmethylene)amino]-1H-1,2,4-triazole-5(4H)-thione
(6h)
Antique white; yield: 83 %; Rf: 0.54 (chloroform: metha-
1
Light pink; yield: 83 %; Rf: 0.54 (chloroform: methanol,
9:1); 1H NMR (400 MHz, DMSO-d6) d 13.53 (s, 1H, NH),
10.11 (s, 1H, imine proton), 7.99 (s, 1H, thiophene proton),
7.91 (s, 1H, thiophene proton), 7.53–7.43 (m, 1H, thio-
phene proton), 7.36–7.21 (m, 2H, aromatic proton),
7.18–7.12 (m, 2H, aromatic proton), 4.07 (s, 2H, aliphatic
CH2); 13C NMR (100 MHz, DMSO-d6) d 166.5, 162.0,
159.6, 150.7, 131.8, 131.7, 129.6, 129.5, 124.8, 122.6,
122.4, 115.8, 115.6, 29.1.
nol, 9:1); H NMR (400 MHz, DMSO-d6) d 13.87 (s, 1H,
NH), 10.04 (s, 1H, imine proton), 7.44–7.37 (m, 2H, aro-
matic proton), 7.35–7.28 (m, 2H, aromatic proton),
7.19–6.91 (m, 4H, aromatic proton), 4.09 (s, 2H, aliphatic
CH2), 3.97 (s, 2H, aliphatic CH2), 3.54 (s, 3H, OCH3); 13
C
NMR (100 MHz, DMSO-d6) d 166.4, 163.5, 161.9, 161.4,
159.3, 148.7, 133.4, 132.0, 127.7, 122.4, 122.1, 114.9,
114.5, 56.9, 30.0, 27.4.
(Z)-3-(2-Methoxybenzyl)-4-[(thiophen-2-
ylmethylene)amino]-1H-1,2,4-triazole-5(4H)-thione
(6i)
(Z)-4-[{2-(4-Hydroxyphenyl)ethylidene}amino]-3-(2-
methoxybenzyl)-1H-1,2,4-triazole-5(4H)-thione (6e)
Light pink; yield: 83 %; Rf: 0.54 (chloroform: methanol,
9:1); 1H NMR (400 MHz, DMSO-d6) d 13.88 (s, 1H, NH),
10.15 (s, 1H, imine proton), 7.95 (s, 1H, thiophene proton),
7.79 (s, 1H, thiophene proton), 7.38–7.29 (m, 2H, aromatic
proton), 7.27–7.26 (m, 1H, thiophene proton), 7.25–7.13
(m, 2H, aromatic proton), 4.09 (s, 2H, aliphatic CH2), 3.54
(s, 3H, OCH3); 13C NMR (100 MHz, DMSO-d6) d 162.1,
159.6, 157.7, 149.5, 136.8, 136.2, 133.4, 131.9, 129.7,
128.9, 124.8, 122.3, 115.6, 57.0, 30.0.
Alice blue; yield: 84 %; Rf: 0.40 (chloroform: methanol,
9:1); 1H NMR (400 MHz, DMSO-d6) d 13.88 (s, 1H, NH),
10.11 (s, 1H, imine proton), 7.44–7.37 (m, 2H, aromatic
proton), 7.35–7.28 (m, 2H, aromatic proton), 7.19–6.91 (m,
4H, aromatic proton), 5.41 (s, 1H, OH), 4.09 (s, 2H, ali-
phatic CH2), 3.97 (s, 2H, aliphatic CH2), 3.55 (s, 3H,
OCH3); 13C NMR (100 MHz, DMSO-d6) d 165.7, 163.5,
162.5, 161.9, 160.2, 148.5, 134.8, 133.1, 126.8, 124.6,
122.7, 116.1, 114.8, 57.0, 30.0, 27.9.
(Z)-3-(4-Nitrobenzyl)-4-[(4-
nitrobenzylidene)amino]-1H-1,2,4-triazole-5(4H)-
thione (6j)
(Z)-4-[{(1H-pyrrol-2-yl)methylene}amino]-3-(4-
hydroxybenzyl)-1H-1,2,4-triazole-5(4H)-thione (6f)
Gray solid; yield: 86 %; Rf: 0.53 (chloroform: methanol,
9:1); 1H NMR (400 MHz, DMSO-d6) d 13.77 (s, 1H, NH),
10.14 (s, 1H, imine proton), 7.53–7.49 (m, 2H, pyrrol
proton), 7.49–7.40 (s, 1H, pyrrol proton), 7.11–7.04 (m,
2H, aromatic proton), 6.89–6.80 (m, 2H, aromatic proton),
5.55 (s, 1H, NH), 4.10 (s, 2H, aliphatic CH2); 13C NMR
(100 MHz, DMSO-d6) d 162.2, 157.0, 151.1, 135.7, 133.1,
133.0, 132.4, 131.2, 122.6, 119.5, 109.9, 30.0.
Moccasin solid; yield: 84 %; Rf: 0.49 (chloroform:
methanol, 9:1); 1H NMR (400 MHz, DMSO-d6) d 13.56 (s,
1H, NH), 10.13 (s, 1H, imine proton), 8.11–7.84 (m, 2H,
aromatic proton), 7.44–7.24 (m, 4H, aromatic proton),
7.19–7.14 (m, 2H, aromatic proton), 4.09 (s, 2H, aliphatic
CH2); 13C NMR (100 MHz, DMSO-d6) d 167.5, 166.4,
159.6, 152.5, 135.4, 133.3, 132.7, 126.9, 126.5, 118.7,
114.4, 30.0.
Spectroscopic analysis
(Z)-4-[{(1H-pyrrol-2-yl)methylene}amino]-3-(4-
nitrobenzyl)-1H-1,2,4-triazole-5(4H)-thione (6g)
Five mM stock solutions of Schiff base derivatives for
triazole 6a and 6b were prepared in acetonitrile (total
volume 10 mL). For spectroscopic measurements, a test
solution of 1 mL was prepared with 2 lL of 5 mM stock
solution in a 1 mL cuvette. The resulting solution was
mixed with the relevant solvent before measurement, and
final volume was fixed at 1 mL for the UV–visible and
fluorescent measurements using a [SCINCO] UV–Vis
Spectrophotometer ‘‘S-3100’’ and FS–2 Fluorescence
spectrometer (SCINCO, Korea), respectively.
Light brown; yield: 86 %; Rf: 0.53 (chloroform: methanol,
9:1); 1H NMR (400 MHz, DMSO-d6) d 13.78 (s, 1H, NH),
10.13 (s, 1H, imine proton), 7.57–7.52 (m, 2H, pyrrol
proton), 7.49–7.45 (s, 1H, pyrrol proton), 7.29–7.17 (m,
2H, aromatic proton), 6.87–6.80 (m, 2H, aromatic proton),
5.55 (s, 1H, NH), 4.07 (s, 2H, aliphatic CH2); 13C NMR
(100 MHz, DMSO-d6) d 161.8, 156.4, 150.0, 135.1, 132.0,
131.8, 131.5, 131.2, 125.5, 120.2, 109.9, 30.1.
123