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KHAIRAT ET AL.
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aromatic), 2966 (CH aliphatic), 1633 (C═O), 1593 (C═N), 1509
(C═C); 1H NMR (DMSO‐d6, 500 MHz): δH 2.29 (s, 3H, CH3), 2.94 (brs,
4H, H3, H5 morpholine protons), 3.51 (brs, 4H, H2, H6 morpholine
protons), 3.84 (s, 3H, OCH3), 6.85 (d, J = 8.0 Hz, 1H, aromatic proton),
7.08 (d, J = 8.0 Hz, 1H, aromatic proton), 7.33 (s, 1H, aromatic pro-
ton), 7.39–7.42 (m, 1H, aromatic protons), 7.52–7.55 (m, 2H, aro-
matic proton), 7.64–7.82 (m, 4H, aromatic proton), 8.34–8.38 (m, 2H,
aromatic proton), 11.72 (s, 1H, NH); 13C NMR (DMSO‐d6, 125 MHz):
δC 13.27, 49.97, 55.54, 65.98, 108.84, 115.44, 122.05, 124.16,
124.16, 125.94, 127.43, 129.01, 139.07, 147.49, 148.06, 148.88,
163.27; MS (EI, eV): m/z (%) 552.2 (100) [M+1]+, 553.2 (30) [M+2]+.
Anal. calcd. for C30H29N7O4 (FW: 551): C, 65.32; H, 5.30; N, 17.78.
Found: C, 65.43; H, 5.45; N, 17.86.
was poured on crushed ice, neutralized by diluted ammonia, and the
crude product was filtered off and dried. The product was re-
crystallized from ethanol to give compounds 42–45, respectively.
Nʹ‐(4‐Hydroxybenzylidene)‐2‐[3‐methyl‐1‐phenyl‐5‐(pyrrolidin‐1‐
yl)‐1H‐pyrazol‐4‐yl]‐1H‐benzo[d]imidazole‐5‐carbohydrazide (42)
Yield = 47%; mp: 196–198°C; Rf = 0.43 (petroleum ether/EtOAc/
ethanol = 1:2:0.25); IR (KBr): υmax/cm−1: 3433 (NH), 2961 (CH ali-
phatic), 1630 (C═O), 1531 (C═N), 1501 (C═C); 1H NMR (DMSO‐d6,
500 MHz): δH 1.71 (s, 4H, H3, H4 pyrrolidine protons), 2.24 (s, 3H,
CH3), 2.97 (s, 4H, H2, H5 pyrrolidine protons), 6.85 (d, J = 8.0 Hz, 2H,
aromatic protons), 7.37–7.40 (m, 1H, aromatic proton), 7.49–7.52 (m,
2H, aromatic protons), 7.57 (d, J = 7.5 Hz, 4H, aromatic protons),
7.65–7.69 (m, 1H, aromatic proton), 7.81 (d, J = 8.0 Hz, 1H, aromatic
proton), 8.22 (s, 1H, aromatic proton), 8.39 (s, 1H, CH=N), 9.94 (s, 1H,
NH), 11.70 (s, 1H, OH); 13C NMR (DMSO‐d6, 125 MHz): δC 13.30,
25.13, 50.47, 115.73, 124.37, 125.53, 127.32, 128.79, 129.09,
139.92, 147.48, 147.84, 159.33, 163.32; MS (EI, eV): m/z (%) 506.20
(100) [M+1]+, 507.3 (27) [M+2]+. Anal. calcd. for C29H27N7O2 (FW:
505): C, 68.89; H, 5.38; N, 19.39. Found: C, 68.72; H, 5.24; N, 19.22.
Nʹ‐(4‐Chlorobenzylidene)‐2‐(3‐methyl‐5‐morpholino‐1‐phenyl‐1H‐
pyrazol‐4‐yl)‐1H‐benzo[d]imidazole‐5‐carbohydrazide (40)
Yield = 45%; mp: 142–144°C; Rf = 0.58 (petroleum ether/EtOAc/
methanol = 1:3:0.5); IR (KBr): υmax/cm−1: 3387 (NH), 3069 (CH aro-
matic), 2920 (CH aliphatic), 1657 (C═O), 1626, 1594 (C═N), 1540
(C═C); 1H NMR (DMSO‐d6, 400 MHz): δH 2.31 (s, 3H, CH3), 2.94 (brs,
4H, H3, H5 morpholine protons), 3.53 (brs, 4H, H2, H6 morpholine
protons), 7.37–7.54 (m, 6H, aromatic protons), 7.75–8.17 (m, 5H,
aromatic protons), 8.51–8.71 (m, 2H, 1H aromatic proton + CH═N),
11.99 (brs, 1H, NH), 12.62 (brs, 1H, NH). Anal. calcd. for
Nʹ‐(3‐Hydroxybenzylidene)‐2‐[3‐methyl‐1‐phenyl‐5‐(pyrrolidin‐1‐
yl)‐1H‐pyrazol‐4‐yl]‐1H‐benzo[d]imidazole‐5‐carbohydrazide (43)
Yield = 40%; mp: 187–189°C; Rf = 0.70 (petroleum ether/EtOAc/
ethanol = 0.5:2:0.5); IR (KBr): υmax/cm−1: 3428 (NH), 2967 (CH ali-
phatic), 1628 (C═O), 1586 (C═N), 1541 (C═C); 1H NMR (DMSO‐d6,
500 MHz): δH 1.71 (s, 4H, H3, H4 pyrrolidine protons), 2.24 (s, 3H,
CH3), 2.98 (s, 4H, H2, H5 pyrrolidine protons), 6.83 (d, J = 7.0 Hz, 1H,
aromatic proton), 7.10 (d, J = 7.5 Hz, 1H, aromatic protons),
7.22–7.27 (m, 2H, aromatic proton), 7.37–7.40 (m, 1H, aromatic
protons), 7.49–7.52 (m, 2H, aromatic protons), 7.57–7.61 (m, 3H,
aromatic proton), 7.73–7.81 (m, 2H, aromatic proton + CH═N), 9.65
(brs, 1H, NH), 11.83 (s, 1H, OH), 12.51 (s, 1H, NH); 13C NMR (DMSO‐
d6, 125 MHz): δC 13.31, 25.13, 50.46, 112.58, 117.30, 118.75,
124.35, 127.31, 129.09, 129.90, 129.96, 135.83, 139.92, 147.82,
157.71, 163.54; MS (EI, eV): m/z (%) 506.2 (100) [M+1]+, 507.3 (25)
[M+2]+. Anal. calcd. for C29H27N7O2 (FW: 505): C, 68.89; H, 5.38; N,
19.39. Found: C, 68.95; H, 5.45; N, 19.48.
C
29H26ClN7O2 (FW: 540): C, 64.50; H, 4.85; Cl, 6.57; N, 18.16.
Found: C, 64.68; H, 4.99; Cl, 6.62; N, 18.25.
Nʹ‐[(Furan‐3‐yl)methylene]‐2‐(3‐methyl‐5‐morpholino‐1‐phenyl‐
1H‐pyrazol‐4‐yl)‐1H‐benzo[d]imidazole‐5‐carbohydrazide (41)
Yield = 36%; mp: 151–153°C; Rf = 0.46 (petroleum ether/EtOAc/
ethanol = 1:2:0.25); IR (KBr): υmax/cm−1: 3430 (NH), 3097 (CH aro-
matic), 2963 (CH aliphatic), 1628 (C═N), 1593 (C═N), 1531 (C═C);
1H NMR (DMSO‐d6, 500 MHz): δH 2.29 (s, 3H, CH3), 2.94 (brs, 4H,
H3, H5 morpholine protons), 3.50–3.51 (m, 4H, H2, H6 morpholine
protons), 6.85 (d, J = 8.0 Hz, 1H, aromatic proton), 7.08 (d, J = 8.0 Hz,
1H, aromatic proton), 7.33 (s, 1H, aromatic proton), 7.39–7.43 (m,
1H, aromatic proton), 7.52–7.56 (m, 1H, aromatic protons),
7.64–7.82 (m, 4H, aromatic proton), 8.13–8.38 (m, 2H, 1H aromatic
proton + CH═N), 11.72 (s, 1H, NH), 12.59 (brs, 1H, NH). Anal. calcd.
for C27H25N7O3 (FW: 495): C, 65.44; H, 5.09; N, 19.79. Found: C,
65.60; H, 5.18; N, 19.85.
Nʹ‐(4‐Hydroxy‐3‐methoxybenzylidene)‐2‐[3‐methyl‐1‐phenyl‐5‐
(pyrrolidin‐1‐yl)‐1H‐pyrazol‐4‐yl]‐1H‐benzo[d]imidazole‐5‐
carbohydrazide (44)
Yield = 45%; mp: 162–164°C; Rf = 0.14 (petroleum ether/EtOAc/
ethanol = 1:2:0.5); IR (KBr): υmax/cm−1: 3434 (NH), 2925 (CH ali-
phatic), 1632 (C═O), 1511 (C═N), 1456 (C═C); 1H NMR (DMSO‐d6,
500 MHz): δH 1.70–1.73 (m, 4H, H3, H4 pyrrolidine protons), 2.23 (s,
3H, CH3), 2.96–2.99 (m, 4H, H2, H5 pyrrolidine protons), 3.84 (s, 3H,
OCH3), 6.85 (d, J = 8.0 Hz, 1H, aromatic protons), 7.08 (d, J = 8.0 Hz,
1H, aromatic proton), 7.33 (s, 1H, aromatic proton), 7.38–7.45 (m,
1H, aromatic protons), 7.56–7.53 (m, 2H, aromatic proton), 7.57 (d,
J = 7.5 Hz, 2H, aromatic proton), 7.65 (brs, 1H, aromatic proton), 7.80
(d, J = 8.0 Hz, 1H, aromatic proton), 8.21 (brs, 1H), 8.38 (s, 1H), 9.55
(s, 1H), 11.70 (s, 1H), 12.54 (s, 1H, NH); 13C NMR (DMSO‐d6,
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4.2.5
General procedure for the synthesis of
compounds 42–45
A
solution of 4‐hydroxybenzaldehyde (0.15 g, 1.24 mmol),
3‐hydroxybenzaldehyde (0.15 g, 1.24 mmol), vanillin (0.19 g,
1.24 mmol), or 4‐chlorobenzaldehyde (0.17 g, 1.24 mmol) in absolute
ethanol (20 ml) was added to a solution of compound 35 (0.5 g,
1.24 mmol) in absolute ethanol (10 ml) and glacial acetic acid (2 ml).
The mixture was refluxed for 6–8 h. Completion of the reaction was
monitored by TLC. After cooling to room temperature, the mixture