Med Chem Res (2013) 22:1660–1673
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4-{4-[2-(4-(2-methoxyquinoxalin-3-yl)piperazin-1-
yl)ethyl]phenyl}-thiazol-2-amine (11a)
for C25H28N6OS: C 65.19, H 6.13, N 18.25, S 6.96; found:
C 65.08, H 6.06, N 18.15, S 6.88.
Recrystallisation Solvent: Ethanol.
% Yield: 66 %
4-{4-[2-(4-(2-methoxyquinoxalin-3-yl)piperazin-1-
yl)ethyl]phenyl}thiazol-2-ol (11d)
1
(0.223 g); mp: 96–98 °C. H NMR (DMSO-d6) (d) ppm:
2.49–2.53 (t, 4H, J = 4.8 Hz, N4(CH2)2); 2.57–2.76 (m,
4H, (CH2)2); 3.27–3.32 (t, 4H, J = 4.8 Hz, N1(CH2)2);
3.72 (s, 3H, OCH3); 3.84 (s, 2H, NH2); 6.88 (s, 1H, thia-
zole); 7.23–8.00 (m, 8H, Ar–H). IR (KBr, m) cm-1: 3348,
3439 (NH stretch); 3065, 3027 (aromatic C–H stretch);
2828, 2763 (aliphatic C–H stretch); 1635, 1616 (aromatic
C=C stretch); 1556 (C=N ring stretch); 1255 (aliphatic
C–N stretch); 1118 (C–O stretch); 820 (para disubstituted
benzene); 709 (aromatic C–H bending). HRMS (ESI) calcd
for C24H26N6OS [M ? H]?: 446.2148; found: 446.2137;
Anal. calculated for C24H26N6OS: C 64.55, H 5.87, N
18.82, S 7.18; found: C 64.49, H 5.69, N 18.84, S 7.14.
Recrystallisation Solvent: Acetone.
% Yield: 78 %
(0.263 g); mp: 122–124 °C. 1H NMR (DMSO-d6) (d) ppm:
2.45-2.52 (t, 4H, J = 4.7 Hz, N4(CH2)2); 2.66–2.78 (m,
4H, (CH2)2); 3.21–3.29 (t, 4H, J = 4.7 Hz, N1(CH2)2);
3.73 (s, 3H, OCH3); 4.74 (s, 1H, thiazole); 5.42 (br s, 1H,
OH); 7.25–8.01 (m, 8H, Ar–H). IR (KBr, m) cm-1: 3558
(OH stretch); 3062, 3027 (aromatic C–H stretch); 2832,
2787 (aliphatic C–H stretch); 1647, 1615 (aromatic C=C
stretch); 1590 (C=N ring stretch); 1262 (aliphatic C–N
stretch); 1077 (C–O stretch); 819 (para disubstituted ben-
zene). 704 (aromatic C–H bending). HRMS (ESI) calcd for
C24H25N5O2S [M ? H]?: 447.1677; found: 447.1674;
Anal. calculated for C24H25N5O2S: C 64.41, H 5.63, N
15.65, S 7.16; found: C 64.26, H 5.60, N 15.51, S 7.08.
4-{4-[2-(4-(2-methoxyquinoxalin-3-yl)piperazin-1-
yl)ethyl]phenyl}-N-ethylthiazol-2-amine (11b)
4-{4-[2-(4-(2-methoxyquinoxalin-3-yl)piperazin-1-
yl)ethyl]phenyl}-5-methyl thiazol-2-amine (11e)
Recrystallisation Solvent: Ether. % Yield: 83 % (0.292 g);
mp: 114–116 °C. 1H NMR (DMSO-d6) (d) ppm: 2.46–2.51
(t, 4H, J = 4.7 Hz, N4(CH2)2); 2.57 (s, 3H, NHCH3);
2.65–2.72 (m, 4H, (CH2)2); 3.29-3.34 (t, 4H, J = 4.7 Hz,
N1(CH2)2); 3.68 (s, 3H, OCH3); 4.11 (s, 1H, NHCH3); 6.71
(s, 1H, thiazole); 7.35–8.04 (m, 8H, Ar–H). IR (KBr, m)
cm-1: 3350 (NH stretch); 3058, 3009 (aromatic C–H
stretch); 2817, 2760 (aliphatic C–H stretch); 1644, 1609
(aromatic C=C stretch); 1587 (C=N ring stretch); 1260
(aliphatic C–N stretch); 1079 (C–O stretch); 812 (para
disubstituted benzene); 712 (aromatic C–H bending).
HRMS (ESI) calcd for C25H28N6OS [M ? H]?: 460.1836;
found: 460.1827; Anal. calculated for C25H28N6OS: C
65.19, H 6.13, N 18.25, S 6.96; found: C 65.08, H 6.06, N
18.15, S 6.88.
% Yield: 42% (0.147 g, oil). 1H NMR (DMSO-d6) (d)
ppm: 2.35 (s, 3H, 5-CH3); 2.46–2.53 (t, 4H, J = 4.7 Hz,
N4(CH2)2); 2.58–2.72(m, 4H, (CH2)2); 2.76 (s, 3H, 2-CH3);
3.23-3.29 (t, 4H, J = 4.7 Hz, N1(CH2)2); 3.79 (s, 3H,
OCH3); 7.39-8.25 (m, 8H, Ar–H). IR (KBr, m) cm-1: 3044,
3026 (aromatic C–H stretch); 2832, 2758 (aliphatic C–H
stretch); 1640, 1604 (aromatic C=C stretch); 1580 (C=N
ring stretch); 1266 (aliphatic C–N stretch); 1112 (C–O
stretch); 809 (para disubstituted benzene), 708 (aromatic
C–H bending). HRMS (ESI) calcd for C26H29N5OS
[M ? H]?: 459.2126; found: 459.2118; Anal. calculated
for C26H29N5OS: C 67.94, H 6.36, N 15.24, S 6.98; found:
C 67.86, H 6.32, N 15.21, S 6.93.
4-{4-[2-(4-(2-methoxyquinoxalin-3-yl)piperazin-1-
yl)ethyl]phenyl}-5-methylthiazol-2-amine (11c)
4-{4-[2-(4-(2-methoxyquinoxalin-3-yl)piperazin-1-
ylethyl]phenyl}-N,5-dimethyl thiazol-2-amine (11f)
% Yield: 48% (0.173 g, oil). 1H NMR (DMSO-d6) (d)
ppm: 2.36 (s, 3H,CH3); 2.49–2.56 (t, 4H, J = 4.8 Hz,
N4(CH2)2); 2.60 (s, 3H, NHCH3); 2.63–2.79 (m, 4H,
(CH2)2); 3.26–3.36 (t, 4H, J = 4.8 Hz, N1(CH2)2); 3.68 (s,
3H, OCH3); 4.28 (s, 1H, NHCH3); 7.12–7.88 (m, 8H,
Ar–H). IR (KBr, m) cm-1: 3478 (NH stretch); 3047, 3115
(aromatic C–H stretch); 2832, 2758 (aliphatic C–H
stretch); 1646, 1613 (aromatic C=C stretch); 1587 (C=N
ring stretch); 1258 (aliphatic C–N stretch); 1115 (C–O
stretch); 818 (para disubstituted benzene), 703 (aromatic
C–H bending). HRMS (ESI) calcd for C26H30N6OS
[M ? H]?: 474.2335; found: 474.2328; Anal. calculated
Recrystallisation Solvent: Ether. % Yield: 70 % (0.244 g);
mp: 68–70 °C. 1H NMR (DMSO-d6) (d) ppm: 2.35 (s, 3H,
CH3); 2.51–2.56 (t, 4H, J = 4.9 Hz, N4(CH2)2); 2.59–2.76
(m, 4H, (CH2)2); 3.25–3.34 (t, 4H, J = 4.9 Hz, N1(CH2)2);
3.69 (s, 3H, OCH3); 3.89 (s, 2H, NH2); 7.18–7.95 (m, 8H,
Ar–H). IR (KBr, m) cm-1: 3440, 3428 (NH stretch); 3058,
3009 (aromatic C–H stretch); 2817, 2775 (aliphatic C–H
stretch); 1642, 1608 (aromatic C=C stretch); 1545 (C=N
ring stretch); 1261 (aliphatic C–N stretch), 1107 (C–O
stretch); 831 (para disubstituted benzene); 711 (aromatic
C–H bending). HRMS (ESI) calcd for C25H28N6OS
[M ? H]?: 460.1786; found: 460.1782; Anal. calculated
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