Medicinal Chemistry Research
14.6 Hz, Ar–H), 7.24 (d, 1H, J = 7.20 Hz, Ar–H), 7.17
(m, 5H, Ar–H), 7.03 (m, 1H, Ar–H), 5.50 (s, 2H, benzylic
protons), 4.14 [two overlapped quartets, 4H, (–CH2–HC–
COOCH2–CH3)2], 3.68 [t, 1H, J = 7.76 Hz, –CH2–CH–
(COOCH2–CH3)2], 3.08 [d, 2H, J = 7.84 Hz, –CH2–CH–
(COOCH2–CH3)2, methylene], 1.21 [t, 6H, J = 7.08 Hz
–CH2–CH–(COOCH2–CH3)2]; 13C NMR (100 MHz,
DMSO-d6): δ 168.18 [2C, –CH2–CH–(COOCH3)2], 150.22
(C-2), 141.92 (C-1″), 139.28 (C-4″), 136.76 (3a and 7a),
133.41 (C-1′), 130.08 (C-2 and C-6), 128.71 (C-3′ and C-
5′), 128.41 (C-3″ and C-5″), 126.45 (C-6″), 120.86 (C-2″),
119.59 (C-7), 118.01 (C-4), 116.13 (C-6), 108.25 (C-5),
60.74 (2C, –CH2–HC–COOCH2–CH3)2)], 53.30 [–CH2
–HC–(COOCH2CH3)2], 33.49 [–CH2–HC–(COOCH2CH3)
2], 29.01 (N–CH2–C6H5), 13.78 [2C, –CH2–HC–(COOCH2
CH3)2]; IR (KBr, cm−1): 3432 (N–H), 2974, 2876 (C–H),
1639 (C=O); ESI–MS (m/z) = 472 [M+1]+; anal. calcd.
(%) for C28H29N3O4: C, 71.32; H, 6.20; N, 8.91. Found: C,
69.80; H, 6.96; N, 9.38.
Dimethyl(4-{[(1-methyl-1H-benzimidazol-2-yl)methyl]
amino}benzyl)malonate (24) Pure product in white viscous
form was obtained by column chromatography; Yield
1
0.063 g, 56.25%; H NMR (400 MHz, DMSO-d6): δ 7.60
(d, 1H, J = 7.48 Hz, Ar–H), 7.45 (d, 1H, J = 7.52 Hz, Ar–
H), 7.24 (m, 2H, Ar–H), 6.91 (d, 2H, J = 8.44 Hz, Ar–H),
6.69 (d, 2H, J = 8.52 Hz, Ar–H), 6.04 (t, 1H, –CH2–N–H of
linker), 4.52 (d, 2H, J = 5.12 Hz, –CH2–N–H of linker),
3.83 (s, 3H, –CH3), 3.65 (t, 1H, J = 7.60 Hz, –CH2–HC–
(COO–CH3)2), 3.61 [s, 6H, –CH2–CH–(COO–CH3)2], 2.96
(d, 2H, J = 7.68 Hz, –CH2–CH–(COO–CH3)2); IR (KBr,
cm−1): 3402 (N–H), 2948, 2837 (C–H), 1647 (C=O);
ESI–MS (m/z) = 382 [M+1]+; anal. calcd. (%) for
C21H23N3O4: C, 66.13; H, 6.08; N, 11.02. Found: C, 66.78;
H, 6.66; N, 11.82.
Dimethyl(4-{[(1-benzyl-1H-benzimidazol-2-yl)methyl]
amino}benzyl)malonate (25) Pure product in white viscous
form was obtained by column chromatography; yield
1
0.073 g, 41.01%; H NMR (400 MHz, CDCl3): δ 7.81 (dd,
5-(4-{[(1-methyl-1H-benzimidazol-2-yl)methyl]amino}ben-
zyl)-1,3-thiazolidine-2,4-dione (22) Pure white solid pro-
duct was obtained by recrystallization in methanol; yield
1H, J = 0.88, 8.24 Hz, –CH2–N–H of linker), 7.30 (m, 7H,
Ar–H), 7.06 (dd, 2H, J = 2.76, 7.68 Hz, Ar–H), 7.01 (dd, 2H,
J = 1.60, 6.88 Hz, Ar–H), 6.60 (dd, 2H, J = 2.20, 8.60 Hz,
Ar–H), 5.42 (s, 2H, benzylic), 4.45 (s, 2H, –CH2–NH– of
linker), 3.69 [s, 3H, –CH2–CH–(COO–CH3)2], 3.68 (s, 3H,
–CH2–CH–(COO–CH3)2), 3.59 [t, 1H, J = 7.72 Hz, –CH2–
HC–(COO–CH3)2], 3.11 [d, 2H, J = 7.80 Hz, –CH2–CH–
(COO–CH3)2]; IR (KBr, cm−1): 3441 (N–H), 2960 and 2930
(C–H), 1726 (C=O) and 1623 (C=N). ESI–MS (m/z) = 457
[M]+; anal. calcd. (%) for C27H27N3O4: C, 70.88; H, 5.95; N,
9.18. Found: C, 69.33; H, 5.02; N, 10.21.
1
0.062 g, 47.32%; m. p. 173–175 °C; H NMR (400 MHz,
DMSO-d6): δ 7.61 (d, 1H, J = 7.76 Hz, Ar–H), 7.46 (d, 1H,
J = 7.68 Hz, Ar–H), 7.23 (m, 2H, Ar–H), 6.95 (d, 2H, J =
8.40 Hz, Ar–H), 6.70 (d, 2H, J = 8.40 Hz, Ar–H), 6.06
(t, 1H, J = 5.08 Hz, –CH2–N–H of linker), 4.52 (d, 2H, J =
5.36 Hz, –CH2–N–H of linker), 4.24 (dd, 1H, J = 3.28,
10.20 Hz, H–C of TZD ring), 3.83 (s, 3H, –CH3), 3.29 (dd,
1H, J = 3.44, 14.80 Hz, H–C–H), 2.68 (dd, J = 10.64,
13.88 Hz, H–C–H); FTIR (KBr, cm−1) νmax: 3428 (N–H),
2949 (C–H Ar), 2855, 2843 (C–H) 1642 (C=O); ESI–MS
(m/z) = 367 [M+1]+; anal. calcd. (%) for C19H18N4O2S: C,
62.28; H, 4.95; N, 15.29. Found: C, 63.02; H, 4.96;
N, 15.11.
Diethyl(4-{[(1-methyl-1H-benzimidazol-2-yl)methyl]amino}
benzyl)malonate (26) Pure product was obtained by col-
umn chromatography; yield 0.052 g, 44.06%; 1H NMR
(400 MHz, DMSO-d6): δ 7.62 (d, 1H, J = 7.80 Hz, Ar–H),
7.42 (d, 1H, J = 8.00 Hz, Ar–H), 7.24 (m, 2H, Ar–H), 6.93
(d, 2H, J = 8.40 Hz, Ar–H), 6.70 (d, 2H, J = 8.40 Hz, Ar–
H), 5.95 (t, 1H, J = 5.24 Hz, –CH2–NH– of linker), 4.53 (d,
2H, J = 5.28 Hz, –CH2–NH– of linker), 4.12 [two over-
lapped quartets, 4H, (–CH2–HC–COOCH2–CH3)2], 3.84 (s,
3H, –CH3), 3.55 (t, 1H, J = 7.86 Hz, –CH2–HC–
(COOCH2–CH3)2), 2.97 (d, 2H, J = 7.84 Hz, –CH2–CH–
(COOCH2–CH3)2), 1.17 [t, 6H, J = 7.20 Hz –CH2–CH–
(COOCH2–CH3)2]; 13C NMR (100 MHz, DMSO-d6): δ
168.31 [2C, –CH2–CH–(COOCH3)2], 146.83 (C-2), 139
(C-1′), 129.09 (3a and 7a), 125.13 (C-4′), 121.21 (C-3′ and
C-5′), 118.58 (C-5 and C-6), 112.32 (C-2′ and C-6′), 109.53
(C-4 and C-7), 60.64 (2C, –CH2–HC–COOCH2–CH3)2)],
53.45 [-CH2–HC–(COOCH2CH3)2], 40.76 [–CH2–NH– of
linker], 33.34 [–CH2–HC–(COOCH2CH3)2], 29.68 [–CH3],
13.76 [2C, –CH2–HC–(COOCH2CH3)2]; IR (KBr, cm−1):
3430 (N–H), 2951, 2844, 2866 (C–H), 1641 (C=O);
5-(4-{[(1-benzyl-1H-benzimidazol-2-yl)methyl]amino}ben-
zyl)-1,3-thiazolidine-2,4-dione (23) Pure white solid pro-
duct was obtained by recrystallization in methanol. Yield
1
0.062 g, 47.32%; m. p. 173–175 °C; H NMR (400 MHz,
DMSO-d6): δ 7.65 (m, 1H, Ar–H), 7.41 (m, 1H, Ar–H), 7.
37 (m, 4H, Ar–H), 7.20 (m, 3H, Ar–H), 6.91 (d, 2H, J =
8.40 Hz, Ar–H), 6.62 (d, 2H, J = 8.48 Hz, Ar–H), 6.15
(t, 1H, J = 5.36 Hz, –CH2–N–H of linker), 5.59 (s, 2H,
benzylic), 4.49 (d, 2H, J = 5.48 Hz, –CH2–N–H of linker),
4.12 (dd, 1H, J = 3.24, 10.60 Hz, H–C of TZD ring), 3.26
(dd, 1H, J = 3.48, 10.04 Hz, H–C–H), 2.54 (dd, 1H, J =
2.52, 9.00 Hz, H–C–H); FTIR (KBr, cm−1) νmax: 3422 and
3391 (N–H), 3069 and 3028 (C–H), 1740 (C=O), 1701
(C=O) and 1618 (C=N); ESI–MS (m/z) = 443 [M+1]+;
anal. calcd. (%) for C25H22N4O2S: C, 67.85; H, 5.01; N,
12.66. Found: C, 68.23; H, 5.66; N, 13.02.