Ethyl 4-(4-hydroxyphenyl)-2-methyl-1,4-dihydrobenzo[4,5]
Ethyl 2-methyl-4-(pyridin-4-yl)-1,4-dihydrobenzo[4,5]imidazo
imidazo[1,2-a]pyrimidine-3-carboxylate (5g)
[1,2-a]pyrimidine-3-carboxylate (5k)
White solid; m.p. 261.6–261.7 °C; 1H NMR (300 MHz, DMSO-
d6) δH: 10.72 (brs, 1H, NH), 9.36 (brs, 1H, OH), 7.31 (d, J = 7.8
Hz, 1H, ArH), 7.21 (d, J = 7.8 Hz, 1H, ArH), 7.13 (d, J = 8.2
Hz, 2H, ArH), 7.00 (t, J = 7.5 Hz, 1H, ArH), 6.92 (t, J = 7.4 Hz,
1H, ArH), 6.60 (d, J = 8.2 Hz, 2H, ArH), 6.29 (s, 1H, CH), 3.98
(q, J = 7.0 Hz, 2H, CH2), 2.42 (s, 3H, CH3), 1.12 (t, J = 7.0 Hz,
3H, CH3); 13C NMR (100 MHz, DMSO-d6) δC: 165.3, 156.8,
145.9, 145.6, 142.3, 132.5, 131.6, 128.3, 128.3, 121.6, 120.0,
116.7, 114.9, 114.9, 109.9, 98.3, 59.3, 55.5, 18.6, 14.1; ESI-MS
m/z 350 [M + H]+; HRMS (ESI) calcd for C20H20N3O3 [M +
H]+ 350.1505, found 350.1509.
White solid; m.p. > 250 °C; 1H NMR (300 MHz, DMSO-d6) δH:
10.95 (brs, 1H, NH), 8.45 (d, J = 5.6 Hz, 2H, ArH), 7.33 (m,
3H, ArH), 7.25 (d, J = 7.7 Hz, 1H, ArH), 7.03 (t, J = 7.6 Hz,
1H, ArH), 6.94 (t, J = 7.6 Hz, 1H, ArH), 6.44 (s, 1H, CH), 4.01
(q, J = 7.1 Hz, 2H, CH2), 2.45 (s, 3H, CH3), 1.12 (t, J = 7.1 Hz,
3H, CH3); 13C NMR (100 MHz, DMSO-d6) δC: 164.9, 150.0,
150.0, 149.9, 147.6, 145.4, 142.2, 131.4, 122.1, 122.1, 122.0,
120.4, 116.9, 109.8, 96.5, 59.5, 54.9, 18.7, 14.1; ESI-MS m/z
335 [M + H]+; HRMS (ESI) calcd for C19H19N4O2 [M + H]+
335.1508, found 335.1506.
Ethyl 2-methyl-4-(p-tolyl)-1,4-dihydrobenzo[4,5]imidazo[1,2-a]
Ethyl 4-(furan-2-yl)-2-methyl-1,4-dihydrobenzo[4,5]imidazo[1,2-
pyrimidine-3-carboxylate (5h)
a]pyrimidine-3-carboxylate (5l)
1
Yellowish powder; m.p. 262.2–262.4 °C; H NMR (300 MHz,
Yellowish solid; m.p. > 245 °C; 1H NMR (300 MHz, DMSO-d6)
δH: 10.84 (brs, 1H, NH), 7.42 (s, 1H, ArH), 7.40 (d, J = 6.0 Hz,,
1H, ArH), 7.34 (d, J = 7.9 Hz, 1H, ArH), 7.12–6.96 (m, 2H,
ArH), 6.54 (s, 1H, ArH), 6.43 (d, J = 3.1 Hz, 1H, ArH), 6.29
(dd, J = 3.1, 1.8 Hz, 1H, CH), 4.04 (q, J = 7.1 Hz, 2H, CH2),
2.44 (s, 3H, CH3), 1.13 (t, J = 7.1 Hz, 3H, CH3); 13C NMR
(100 MHz, DMSO-d6) δC: 165.1, 152.7, 147.8, 145.6, 142.6,
142.2, 131.5, 121.9, 120.3, 116.8, 110.4, 109.8, 107.7, 94.3,
59.3, 49.1, 18.7, 14.1; ESI-MS m/z 324 [M + H]+; HRMS (ESI)
calcd for C18H18N3O3 [M + H]+ 324.1348, found 324.1344.
DMSO-d6) δH: 10.81 (brs, 1H, NH), 7.32 (d, J = 7.8 Hz, 1H,
ArH), 7.20 (d, J = 7.9 Hz, 3H, ArH), 7.07–6.97 (m, 3H, ArH),
6.91 (t, J = 7.2 Hz, 1H, ArH), 6.35 (s, 1H, CH), 3.98 (q, J = 7.1
Hz, 2H, CH2), 2.43 (s, 3H, CH3), 2.15 (s, 3H, CH3), 1.12 (t, J =
7.1 Hz, 3H, CH3); 13C NMR (100 MHz, DMSO-d6) δC: 165.2,
146.3, 145.6, 142.3, 139.1, 136.9, 131.5, 128.9, 128.9, 126.9,
126.9, 121.7, 120.1, 116.7, 109.9, 97.9, 59.3, 55.6, 20.6, 18.6,
14.1; ESI-MS m/z 348 [M + H]+; HRMS (ESI) calcd for
C21H22N3O2 [M + H]+ 348.1712, found 348.1710.
Ethyl 4-(4-hydroxy-3-methoxyphenyl)-2-methyl-1,4-
dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carboxylate (5i)
Ethyl 4-ethyl-2-methyl-1,4-dihydrobenzo[4,5]imidazo[1,2-a]
pyrimidine-3-carboxylate (5m)
White solid; m.p. > 270 °C; 1H NMR (300 MHz, DMSO-d6) δH:
10.70 (brs, 1H, NH), 8.94 (brs, 1H, OH), 7.30 (dd, J = 7.5, 3.6
Hz, 2H, ArH), 6.97 (m, 3H, ArH), 6.68–6.55 (m, 2H, ArH),
6.30 (s, 1H, CH), 4.00 (q, J = 7.1 Hz, 2H, CH2), 3.70 (s, 3H,
CH3), 2.42 (s, 3H, CH3), 1.14 (t, J = 7.1 Hz, 3H, CH3); 13C
NMR (100 MHz, DMSO-d6) δC: 165.3, 146.9, 146.1, 145.9,
145.7, 142.3, 133.2, 131.6, 121.7, 120.0, 119.3, 116.7, 115.4,
111.9, 110.1, 98.3, 59.3, 55.7, 55.63, 18.6, 14.2; ESI-MS m/z
380 [M + H]+; HRMS (ESI) calcd for C21H22N3O4 [M + H]+
380.1610, found 380.1614.
White solid; m.p. 192.5–192.9 °C; 1H NMR (300 MHz, DMSO-
d6) δH: 10.49 (brs, 1H, NH), 7.50–7.28 (m, 2H, ArH), 7.06 (m,
2H, ArH), 5.58 (t, J = 3.6 Hz, 1H, CH), 4.14 (q, J = 7.1 Hz, 2H,
CH2), 2.37 (s, 3H, CH3), 2.08–1.90 (m, 1H, CH2), 1.66 (m, 1H,
CH2), 1.23 (t, J = 7.1 Hz, 3H, CH3), 0.48 (t, J = 7.4 Hz, 3H);
13C NMR (100 MHz, DMSO-d6) δC: 165.5, 148.2, 146.9, 142.3,
131.4, 121.6, 120.2, 116.9, 109.4, 94.9, 59.3, 52.3, 26.4, 18.7,
14.3, 7.1; ESI-MS m/z 286 [M + H]+; HRMS (ESI) calcd for
C16H20N3O2 [M + H]+ 286.1556, found 286.1558.
Ethyl 4-(4-cyanophenyl)-2-methyl-1,4-dihydrobenzo[4,5]imidazo
[1,2-a]pyrimidine-3-carboxylate (5j)
Ethyl 2-methyl-4-propyl-1,4-dihydrobenzo[4,5]imidazo[1,2-a]
pyrimidine-3-carboxylate (5n)
Yellowish powder; m.p. > 275 °C; 1H NMR (300 MHz, DMSO-
d6) δH: 10.96 (brs, 1H, NH), 7.72 (d, J = 8.0 Hz, 2H, ArH), 7.54
(d, J = 8.1 Hz, 2H, ArH), 7.33 (d, J = 7.7 Hz, 1H, ArH), 7.24
(d, J = 7.8 Hz, 1H, ArH), 7.02 (t, J = 7.4 Hz, 1H, ArH), 6.93 (t,
J = 7.5 Hz, 1H, ArH), 6.51 (s, 1H, CH), 3.98(q, J = 7.0 Hz, 2H),
2.46 (s, 3H, CH3), 1.11 (t, J = 7.0 Hz, 3H, CH3); 13C NMR
(100 MHz, DMSO-d6) δC: 164.9, 147.4, 147.1, 145.3, 142.2,
132.5, 132.5, 131.3, 128.2, 128.2, 122.0, 120.4, 118.5, 116.9,
110.6, 109.8, 96.9, 59.5, 55.5, 18.7, 14.0; ESI-MS m/z 359 [M +
H]+; HRMS (ESI) calcd for C21H19N4O2 [M + H]+ 359.1508,
found 359.1505.
White solid; m.p. 191.2–191.3 °C; 1H NMR (300 MHz, DMSO-
d6) δH: 10.53 (brs, 1H, NH), 7.38 (m, 2H, ArH), 7.05 (m, 2H,
ArH), 5.55 (t, J = 3.6 Hz, 1H, CH), 4.14 (q, J = 6.3 Hz, 2H,
CH2), 2.36 (s, 3H, CH3), 1.96–1.80 (m, 1H, CH2), 1.61 (m, 1H,
CH2), 1.23 (t, J = 6.3 Hz, 3H, CH3), 1.17 (m, 1H, CH2), 0.68
(m, 4H, CH2CH3); 13C NMR (100 MHz, DMSO-d6) δC: 165.5,
147.9, 146.8, 142.3, 131.5, 121.6, 120.2, 116.8, 109.32, 95.8,
59.4, 51.6, 36.2, 18.7, 16.2, 14.3, 13.7; ESI-MS m/z 300 [M +
H]+; HRMS (ESI) calcd for C17H22N3O2 [M + H]+ 300.1712,
found 300.1715.
844 | Green Chem., 2012, 14, 840–846
This journal is © The Royal Society of Chemistry 2012