1026
M. Gupta
Vol 44
C-7H, J= 7.2 Hz), 8.62 (bs, 1H, NH); ms: m/z 304 (M+). Anal.
Calcd. for C17H12N5F: C, 67.10; H, 3. 94; N, 23.02. Found: C,
67.02; H, 3.903; N, 22.92.
from the centre of the discs. The percentage zone of
inhibition was calculated by the formula: I% = C-T/C X
100, Where, I= inhibition, C= diameter of zone of micro-
organisms in check, T= diameter of the disc.
The zone of inhibition was measured after 24 h,
fluconazole (500 μg/mL and 1000 μg/mL) was used as
control standard.
3-(2'-Chlorophenyl)-6-(4'-bromophenyl)-5H-[1,2,4]tria-
zolo[4,3-b[1,2,4]triazepine (8b). This compound was obtained
as pale yellow coloured shining solid (ethyl acetate), mp 202-
204°; ir (potassium bromide): 3181 (NH), 3062 (aromatic C-H),
1693 (C=N), 1447 (C-N), 719 (C-Cl), 540 (C-Br); 1H nmr
(CDCl3+DMSO-d6): ꢀ 7.10-7.20 (m, 2H, Harom), 7.25-7.32 (m,
2H, Harom), 7.38-7.50 (m, 4H, Harom and d, 1H buried C-8,
J=8.2 Hz), 7.68(d, 1H, C-7H, J= 7.2 Hz), 8.50 (bs, 1H, NH);
ms: m/z 399.5 (M+ ). Anal. Calcd. for C17H11N5BrCl: C, 51.06;
H, 2.75; N, 17.5. Found: C, 51.00; H, 2.70; N,17.1.
EXPERIMENTAL
General. All the melting points were determined on a Tempo
1
melting point apparatus and are uncorrected. H NMR spectra
3-(4'-Chlorophenyl)-6-(4'-fluorophenyl)-5H-[1,2,4]tria-
zolo[4,3-b][1,2,4]triazepine (8c). This compound was obtained
as pale yellow shining solid (ethyl acetate), mp 175-177°C: ir
(potassium bromide): 3163 (NH), 3063 (aromatic C-H), 1644
(C=N), 818 (C-F), 759 (C-Cl); 1H nmr (CDCl3+DMSO-d6):
6.95-7.22 (m, 4H, Harom), 7.26-7.45 (m, 4H, Harom), 7.52 (d,
1H, C-8H, J= 8.2 Hz), 7.70 (d,1H, C-7H, J=7.2 Hz), 8.57 (bs,
1H, NH); ms: m/z 338.5 (M+). Anal. Calcd. for C17H11N5ClF: C,
60.26; H, 3.24; N, 20.67. Found: C, 60.21; H, 3.18; N, 20.27.
3-Benzyl-6-(4'-chlorophenyl)-5H-[1,2,4]triazolo[4,3-b]-
[1,2,4]triazepine (8d). This compound was obtained as yellow
coloured solid (ethyl acetate), mp 214-216°C: ir (potassium
bromide): 3162 (NH), 3028 (aromatic C-H), 1692 (C=N), 1438
(C-N), 759 (C-Cl); 1H nmr ( CDCl3+DMSO-d6): 4.00 (s, 2H, Ar-
CH2), 7.05-7.25 (m, 5H, Harom), 7.28-7.45 (m, 4H, Harom),
7.50 (d,1H, C-8H, J=8.2 Hz), 7.68 (d,1H, C-7H, J=7.2 Hz), 8.57
(bs, 1H, NH); ms: m/z 318 (M+). Anal. Calcd. for C18H14N5Cl: C,
67.92; H, 4.40; N, 22.01. Found: C, 67.88; H, 4.38; N, 4. 38; N,
21.90.
3-(4'-Nitrophenyl)-6-(4'-chlorophenyl)-5H-[1,2,4]triazole-
[4,3-b][1,2,4]triazepine (8e). This compound was obtained as
pale yellow shining solid (ethyl acetate), mp 232-234°C; ir
(potassium bromide): 3280 (NH), 3176 (aromatic C-H), 1663
(C=N), 1597 (NO2), 1407 (C-N), 752 (C-Cl); 1H nmr
(CDCl3+DMSO-d6): 7.10-7.32 (m, 4H, Harom), 7.50 (d, 1H, C-
8H, J=8.2 Hz), 7.62-7.80 (m, 2H, Harom and d, 1H buried C-
7H, J= 7.2 Hz), 8.00-8.12 (m, 2H, Harom), 8.60 (bs, 1H, NH);
ms: m/z 366.5 (M+). Anal. Calcd. for C17H11N6O2Cl: C, 55.66; H,
3.00; N, 22.91. Found: C, 55.62; H, 2.9 6; N, 22.88.
were recorded on a Bruker DPX-200 NMR spectrometer (200
MHz) in CDCl3 + DMSO-d6 using tetramethylsilane as an
internal standard and IR spectra were recorded using KBr disc
on a Perkin Elmer FTIR spectrophotometer. The mass spectral
data was obtained on a JEOL JMS-D 300 spectrometer. The
elemental analysis were performed on a simple CHNS-932
Analyser (Leco). The reactions were carried out in domestic
microwave oven LG-MS-255R with maximum output power of
900 W and by using pre-heated oil-bath.
General Procedure for the Synthesis of Compounds 8a-j.
Microwave Heating. A mixture of 5-aryl-3,4-diamino-1,2,4-
triazole 5 (5 mmol), ꢀ-chlorocinnamaldehyde 7 (5 mmol), N,N-
dimethylformamide (0.18 g, 2.5 mmol) as an energy transfer
medium and catalytic amount of p-TsOH (200 mg) was taken in
a borosil beaker and mixed properly with the help of a glass rod
(5 s). The mixture was then exposed to microwave irradiation
for an appropriate time (monitored by TLC, shown in Table 1)
followed by cooling time of 5 s each at 640 W. After completion
of the reaction, crushed ice was added and the solid obtained
was collected by filtration, washed with water and dried. The
crude product was purified either by crystallization from EtOAc
or by passing through a column of alumina and elution with
ethyl acetate and petroleum ether. The physical data of
synthesized compounds is given in Table 1. The structures of the
products were confirmed by IR, 1H NMR, mass spectral data and
elemental analysis.
Oil-bath Heating. A mixture of 5-aryl-3,4-diamino-1,2,4-
triazole 5 (5 mmol), ꢀ-chlorocinnamaldehyde 7 (5 mmol), N,N-
dimethylformamide (50 ml) and catalytic amount of p-TsOH
(200 mg) was taken in a round bottomed flask (100 ml). The
reaction mixture was stirred in an oil-bath at 80 °C for the
appropriate time (monitored by TLC, shown in Table 1). After
completion of the reaction, the reaction mixture was cooled to
room temperature and poured onto the crushed ice. The solid
obtained was filtered, washed with water and dried. The crude
product was purified either by crystallization from EtOAc or
passing through a column of alumina and elution with
ethylacetate and petroleum ether. The physical data of the
synthesized compounds is given in Table 1. The structures of the
products were confirmed by IR, 1H NMR, mass spectral data and
elemental analysis.
3-Phenyl-6-(4'-bromophenyl)-5H-[1,2,4]triazolo[4,3-b]-
[1,2,4]triazepine (8f). This compound was obtained as yellow
coloured solid (ethyl acetate), mp 168-170°C; ir (potassium
bromide): 3162 (NH), 3050 (aromatic C-H), 1692 (C=N), 1440
1
(C-N), 560 (C-Br); H nmr (CDCl3+DMSO-d6): 7.02-7.10 (m,
3H, Harom), 7.13-7.22 (m, 2H, Harom), 7.30- 7.53 (m, 4H,
Harom and d, 1H buried C-8H, J= 8.2 Hz), 7.67 (d, 1H, C-7H,
J= 7.2 Hz), 8.55 (bs, 1H, NH); ms: m/z 365 (M+). Anal. Calcd.
for C17H12N5Br: C, 55.89; H, 3.28; N, 19.17. Found: C, 55.86; H,
3.26; N, 19.16.
3-(2'-Chlorophenyl)-6-(4'-nitrophenyl)-5H-[1,2,4,]triazole-
[4,3-b][1,2,4]triazepine (8g). This compound was obtained as
brown coloured shining solid (ethyl acetate), mp182-184°C; ir
(potassium bromide): 3174 (NH), 3010 (aromatic C-H str), 1668
3-Phenyl-6-(4'-fluorophenyl)-5H-[1,2,4]triazolo[4,3-b][1,2,4]-
triazepine (8a). This compound was obtained as orange
coloured shining solid (ethyl acetate), mp 218-220°; ir
(potassium bromide): 3142 (NH), 3048 (aromatic C-H), 1652
1
(C=N), 1550 (NO2), 724 (C-Cl); H nmr (CDCl3+DMSO-d6):
7.21-7.26 (m, 3H, Harom), 7.32-7.54 (m, 2H, Harom and d, 1H
buried C-8H, J=8.2 Hz), 7.65 (d, 1H, C-7H, J= 7. 3 Hz), 8.05-
8.15 (m, 3H, Harom), 8.60 (bs, 1H, NH); ms: m/z 366.5 (M+).
Anal. Calcd. for C17H11N6O2Cl: C, 55.66; H, 3.00; N, 22.91.
Found: C, 54.98; H, 2.88; N, 22.80.
1
(C=N), 1432 (C-N), 810 (C-F); H nmr (CDCl3+DMSO-d6): ꢀ
6.90-7.25 (m, 3H, Harom), 7.30-7.38 (m, 3H, Harom), 7.49-7.55
(m, 3H, Harom and d, 1H buried C-8H, J= 8.2 Hz), 7.71(d, 1H,