Journal of Medicinal Chemistry
Article
1H), 7.40 (t, J = 8.7 Hz, 1H), 6.94 (d, J = 8.7 Hz, 1H), 3.80 (s, 3H),
3.75 (s, 3H); HRMS-ESI+ m/z calcd for C21H18FN5O3 408.1466 (M +
H+), found 408.4188 (M + H+).
the procedure outlined for 23: mp 250−252 °C; 1H NMR (300 MHz,
DMSO-d6) δ 13.12 (s, 1H), 9.46 (s, 1H), 8.61 (s, 1H), 8.13 (s, 1H),
8.02−8.01 (m, 2H), 7.94 (d, J = 0.9 Hz, 1H), 7.77 (d, J = 8.4 Hz, 1H),
7.68 (dd, J = 8.4, 0.9 Hz, 1H), 7.58 (d, J = 0.9 Hz, 1H), 7.55 (dd, J =
8.4, 2.4 Hz, 1H), 6.91 (d, J = 8.4 Hz, 1H), 3.76 (s, 3H), 3.71 (s, 3H);
HRMS-ESI+ m/z calcd for C21H18N6O2 387.1564 (M + H+), found
387.1579 (M + H+).
6-(1H-Benzo[d]imidazol-5-yl)-N-(3,4-dimethoxyphenyl)-
imidazo[1,2-a]pyrazin-8-amine (56). The target compound was
obtained following the procedure outlined for 23: mp 135−137 °C;
1H NMR (300 MHz, DMSO-d6) δ 12.58 (s, 0.5H), 12.51 (s, 0.5H),
9.48 (s, 1H), 8.60 (s, 1H), 8.34−8.10 (m, 3H), 7.98 (s, 1H), 7.91−
7.82 (m, 1H), 7.73−7.62 (m, 3H), 6.97 (d, J = 9.0 Hz, 1H), 3.87 (s,
1.5H), 3.82 (s, 1.5H), 3.77 (s, 3H); HRMS-ESI+ m/z calcd for
C21H18N6O2 387.1564 (M + H+), found 387.1578 (M + H+).
6-(1H-Benzo[d][1,2,3]triazol-6-yl)-N-(3,4-dimethoxyphenyl)-
imidazo[1,2-a]pyrazin-8-amine (57). The target compound was
obtained following the procedure outlined for 23: mp 244−250 °C;
1H NMR (300 MHz, DMSO-d6) δ 9.54 (s, 1H), 8.71 (s, 1H), 8.49 (s,
1H), 8.10 (d, J = 2.4 Hz, 1H), 8.03−7.94 (m, 3H), 7.65 (s, 1H), 7.61
(dd, J = 8.7, 2.4 Hz, 1H), 6.98 (d, J = 8.7 Hz, 1H), 3.85 (s, 3H), 3.77
(s, 3H); HRMS-ESI+ m/z calcd for C20H17N7O2 388.1516 (M + H+),
found 388.1515 (M + H+).
N-(3,4-Dimethoxyphenyl)-6-(1H-indol-5-yl)imidazo[1,2-a]-
pyrazin-8-amine (58). The target compound was obtained following
the procedure outlined for 23: mp 235−237 °C; 1H NMR (300 MHz,
DMSO-d6) δ 11.17 (s, 1H), 9.43 (s, 1H), 8.51 (s, 1H), 8.26 (m, 2H),
7.96 (d, J = 0.9 Hz, 1H), 7.75 (dd, J = 8.7, 1.5 Hz, 1H), 7.61 (d, J = 0.9
Hz, 1H), 7.57 (dd, J = 8.7, 2.4 Hz, 1H), 7.47 (d, J = 8.7 Hz, 1H), 7.38
(t, J = 2.4 Hz, 1H), 6.97 (d, J = 8.7 Hz, 1H), 6.47 (m, 1H), 3.87 (s,
3H), 3.76 (s, 3H); HRMS-ESI+ m/z calcd for C22H19N5O2 386.1612
(M + H+), found 388.1616 (M + H+).
N-(3,4-Dimethoxyphenyl)-6-(1-methyl-1H-indazol-6-yl)-
imidazo[1,2-a]pyrazin-8-amine (59). The target compound was
obtained following the procedure outlined for 23: mp 185−187 °C;
1H NMR (300 MHz, DMSO-d6) δ 9.55 (s, 1H), 8.71 (s, 1H), 8.22 (s,
1H), 8.10−8.07 (m, 2H), 8.02 (s, 1H), 7.83 (m, 2H), 7.67 (s, 1H),
7.67−7.64 (m, 1H), 6.99 (d, J = 8.7 Hz, 1H), 4.12 (s, 3H), 3.83 (s,
3H), 3.77 (s, 3H); HRMS-ESI+ m/z calcd for C22H20N6O2 401.1721
(M + H+), found 401.1726 (M + H+).
N-(3,4-Dimethoxyphenyl)-6-(1-methyl-1H-indazol-5-yl)-
imidazo[1,2-a]pyrazin-8-amine (60). The target compound was
obtained following the procedure outlined for 23: mp 210−212 °C;
1H NMR (300 MHz, DMSO-d6) δ 9.51 (s, 1H), 8.62 (s, 1H), 8.43 (s,
5-(8-((3,4-Dimethoxyphenyl)amino)imidazo[1,2-a]pyrazin-
6-yl)-2-methylbenzamide (47). The target compound was obtained
1
following the procedure outlined for 42: mp 243−244 °C; H NMR
(300 MHz, DMSO-d6) δ 9.50 (s, 1H), 8.63 (s, 1H), 8.14 (d, J = 2.4
Hz, 1H), 8.02 (d, J = 1.5 Hz, 1H), 7.98 (s, 1H), 7.94 (dd, J = 8.1, 1.5
Hz, 1H), 7.80 (s, 1H), 7.64 (s, 1H), 7.53 (dd, J = 8.7, 2.4 Hz, 1H),
7.43 (s, 1H), 7.34 (d, J = 8.1 Hz, 1H), 6.94 (d, J = 8.7 Hz, 1H), 3.81
(s, 3H), 3.75 (s, 3H), 2.40 (s, 3H); HRMS-ESI+ m/z calcd for
C22H21N5O3 404.1717 (M + H+), found 404.1728 (M + H+).
5-(8-((3,4-Dimethoxyphenyl)amino)imidazo[1,2-a]pyrazin-
6-yl)-2-methoxybenzamide (48). The target compound was
obtained following the procedure outlined for 42: mp 228−230 °C
1
dec; H NMR (300 MHz, DMSO-d6) δ 9.58 (s, 1H), 8.60 (s, 1H),
8.44 (s, 1H), 8.11−8.06 (m, 2H), 8.01 (s, 1H), 7.70 (m, 2H), 7.61 (s,
1H), 7.55 (d, J = 8.7 Hz, 1H), 7.26 (d, J = 8.7 Hz, 1H), 6.94 (d, J = 8.7
Hz, 1H), 3.94 (s, 3H), 3.81 (s, 3H), 3.75 (s, 3H); HRMS-ESI+ m/z
calcd for C22H21N5O4 420.1666 (M + H+), found 420.1688 (M + H+).
3-(8-((3,4-Dimethoxyphenyl)amino)imidazo[1,2-a]pyrazin-
6-yl)-4-methylbenzamide (49). The target compound was obtained
following the procedure outlined for 42: mp > 250 °C; 1H NMR (300
MHz, DMSO-d6) δ 9.47 (s, 1H), 8.14 (s, 1H), 8.03−8.00 (m, 2H),
7.95−7.90 (m, 2H), 7.81 (dd, J = 8.1, 1.7 Hz, 1H), 7.66 (s, 1H), 7.55
(dd, J = 8.7, 2.3 Hz, 1H), 7.39 (d, J = 8.1 Hz, 1H), 7.30 (bs, 1H), 6.88
(d, J = 8.7 Hz, 1H), 3.70 (s, 3H), 3.68 (s, 3H), 2.47 (s, 3H); HRMS-
ESI+ m/z calcd for C22H21N5O3 404.1717 (M + H+), found 404.1735
(M + H+).
4-(8-((3,4-Dimethoxyphenyl)amino)imidazo[1,2-a]pyrazin-
6-yl)-2-fluorobenzamide (50). The target compound was obtained
following the procedure outlined for 42: mp > 250 °C; 1H NMR (300
MHz, DMSO-d6) δ 9.60 (s, 1H), 8.77 (s, 1H), 8.04 (d, J = 2.1 Hz,
1H), 7.99 (s, 1H), 7.92−7.87 (m, 2H), 7.81−7.75 (m, 1H), 7.70−7.65
(m, 3H), 7.56 (dd, J = 8.7, 2.1 Hz, 1H), 6.97 (d, J = 8.7 Hz, 1H), 3.84
(s, 3H), 3.76 (s, 3H); HRMS-ESI+ m/z calcd for C21H18FN5O3
408.1466 (M + H+), found 408.1479 (M + H+).
4-(8-((3,4-Dimethoxyphenyl)amino)imidazo[1,2-a]pyrazin-
6-yl)-2-methylbenzamide (51). The target compound was obtained
1
following the procedure outlined for 42: mp 225−237 °C; H NMR
(300 MHz, DMSO-d6) δ 9.52 (s, 1H), 8.64 (s, 1H), 8.11 (d, J = 2.3
Hz, 1H), 7.99−7.98 (m, 1H), 7.92−7.84 (m, 2H), 7.74 (bs, 1H),
7.65−7.64 (m, 1H), 7.57 (dd, J = 8.7, 2.3 Hz, 1H), 7.48 (d, J = 7.9 Hz,
1H), 7.36 (bs, 1H), 6.97 (d, J = 8.7 Hz, 1H), 3.83 (s, 3H), 3.76 (s,
3H), 2.45 (s, 3H); HRMS-ESI+ m/z calcd for C22H21N5O3 404.1717
(M + H+), found 404.1718 (M + H+).
1H), 8.18 (d, J = 2.4 Hz, 1H), 8.12 (s, 1H), 8.05 (dd, J = 9.0, 1.5 Hz,
1H), 7.98 (s, 1H), 7.74 (d, J = 9.0 Hz, 1H), 7.64 (s, 1H), 7.60 (dd, J =
9.0, 2.4 Hz, 1H), 6.99 (d, J = 9.0 Hz, 1H), 4.09 (s, 3H), 3.87 (s, 3H),
3.77 (s, 3H); HRMS-ESI+ m/z calcd for C22H20N6O2 401.1721 (M +
H+), found 401.1739 (M + H+).
4-(8-((3,4-Dimethoxyphenyl)amino)imidazo[1,2-a]pyrazin-
6-yl)-2-methoxybenzamide (52). The target compound was
obtained following the procedure outlined for 42: mp 221−222 °C
1
dec; H NMR (300 MHz, DMSO-d6) δ 9.56 (s, 1H), 8.75 (s, 1H),
6-(8-((3,4-Dimethoxyphenyl)amino)imidazo[1,2-a]pyrazin-
6-yl)-2H-benzo[b][1,4]oxazin-3(4H)-one (61). The target com-
pound was obtained following the procedure outlined for 23: mp
7.99 (d, J = 1.2 Hz, 1H), 7.92 (d, J = 8.1 Hz, 1H), 7.87 (d, J = 2.4 Hz,
1H), 7.77−7.66 (m, 5H), 7.54 (bs, 1H), 6.97 (d, J = 8.7 Hz, 1H), 4.01
(s, 3H), 3.79 (s, 3H), 3.76 (s, 3H); HRMS-ESI+ m/z calcd for
C22H21N5O4 420.1666 (M + H+), found 420.1681 (M + H+).
4-(8-((3,4-Dimethoxyphenyl)amino)imidazo[1,2-a]pyrazin-
6-yl)-3-methylbenzamide (53). The target compound was obtained
1
235−237 °C; H NMR (300 MHz, DMSO-d6) δ 10.94 (s, 1H), 9.46
(s, 1H), 8.41(s, 1H), 7.99 (s, 1H), 7.91 (d, J = 2.1 Hz, 1H), 7.74 (dd, J
= 8.7, 2.1 Hz, 1H), 7.62 (s, 1H), 7.56−7.51 (m, 2H), 7.04 (d, J = 8.7
Hz, 1H), 6.98 (d, J = 8.7 Hz, 1H), 4.62 (s, 2H), 3.78 (s, 3H), 3.77 (s,
3H); HRMS-ESI+ m/z calcd for C22H19N5O4 418.1510 (M + H+),
found 418.1512 (M + H+).
1
following the procedure outlined for 42: mp 238−241 °C; H NMR
(300 MHz, DMSO-d6) δ 9.48 (s, 1H), 8.15 (s, 1H), 8.01−7.98 (m,
2H), 7.86−7.76 (m, 3H), 7.66−7.58 (m, 3H), 7.36 (bs, 1H), 6.89 (d, J
= 8.7 Hz, 1H), 3.71 (s, 6H), 2.50 (s, 3H); HRMS-ESI+ m/z calcd for
C22H21N5O3 404.1717 (M + H+), found 404.1736 (M + H+).
N-(3,4-Dimethoxyphenyl)-6-(1H-indol-6-yl)imidazo[1,2-a]-
pyrazin-8-amine (54). The target compound was obtained following
the procedure outlined for 23: mp 215−217 °C; 1H NMR (300 MHz,
DMSO-d6) δ 11.23 (s, 1H), 9.45 (s, 1H), 8.53 (s, 1H), 8.12 (d, J = 2.4
Hz, 1H), 8.08 (s, 1H), 7.98 (s, 1H), 7.67−7.59 (m, 4H), 7.39 (t, J =
2.7 Hz, 1H), 6.97 (d, J = 8.7 Hz, 1H), 6.45 (m, 1H), 3.82 (s, 3H), 3.76
(s, 3H); HRMS-ESI+ m/z calcd for C22H19N5O2 386.1612 (M + H+),
found 386.1630 (M + H+).
7-(8-((3,4-Dimethoxyphenyl)amino)imidazo[1,2-a]pyrazin-
6-yl)-2H-benzo[b][1,4]oxazin-3(4H)-one (62). The target com-
pound was obtained following the procedure outlined for 23: mp >
1
250 °C; H NMR (300 MHz, DMSO-d6) δ 10.81 (s, 1H), 9.48 (s,
1H), 8.53 (s, 1H), 8.04 (d, J = 2.4 Hz, 1H), 7.94 (s, 1H), 7.62−7.56
(m, 4H), 6.99−6.95 (m, 2H), 4.62 (s, 2H), 3.82 (s, 3H), 3.75 (s, 3H);
HRMS-ESI+ m/z calcd for C22H19N5O4 418.1510 (M + H+), found
418.1499 (M + H+).
6-(3,4-Dihydro-2H-benzo[b][1,4]oxazin-6-yl)-N-(3,4-
dimethoxyphenyl)imidazo[1,2-a]pyrazin-8-amine (63). The
target compound was obtained following the procedure outlined for
23: mp 179−182 °C; 1H NMR (300 MHz, DMSO-d6) δ 9.39 (s, 1H),
N-(3,4-Dimethoxyphenyl)-6-(1H-indazol-6-yl)imidazo[1,2-a]-
pyrazin-8-amine (55). The target compound was obtained following
3868
dx.doi.org/10.1021/jm500228a | J. Med. Chem. 2014, 57, 3856−3873