May 2009
A Facile and Efficient Synthesis of Novel Pyrimido[5,4-b][4,7]phenanthroline-
9,11(7H,8H,10H,12H)-dione Derivatives via Microwave-assisted Multicomponent Reactions
565
Table 2
Synthesis of 4 under microwave irradiation.
Entry
4
R
Time (min)
Yield (%)
M.P. (ꢀC)
1
2
3
4
5
6
7
8
9
4a
4b
4c
4d
4e
4f
4g
4h
4i
4-FC6H4
4-ClC6H4
4-BrC6H4
6
8
89
90
92
78
86
81
83
81
72
>300
>300
>300
>300
>300
>300
>300
>300
>300
6
14
6
3,4-(CH3O)2C6H3
3-NO2C6H4
4-CH3C6H4
C6H5
12
10
13
15
4-OH-3-NO2C6H3
3,4-OCH2OC6H3
1
973, 820 cmꢁ1; H NMR: d 10.66 (s, 1H, NH), 10.45 (s, 1H,
NH), 9.22 (s, 1H, NH), 8.69–8.70 (m, 1H, ArH), 8.38 (d, 1H,
J ¼ 8.4 Hz, ArH), 7.91 (d, 1H, J ¼ 8.8 Hz, ArH), 7.63 (d,
1H, J ¼ 8.8 Hz, ArH),7.41 (dd, 1H, J ¼ 8.4, 4.0 Hz, ArH),
7.07 (d, 1H, J ¼ 2.0 Hz, ArH), 6.70 (d, 1H, J ¼ 8.4 Hz,
ArH), 6.55 (dd, 1H, J ¼ 8.4, 2.0 Hz, ArH), 5.70 (s, 1H, CH),
3.66 (s, 3H, OCH3), 3.61 (s, 3H, OCH3). Anal. calcd for
C22H18N4O4: C, 65.66; H, 4.51; N, 13.92; Found C, 65.60; H,
4.50; N, 13.95.
General procedure for the syntheses of compounds 4
with microwave irradiation. Typically, in a 10 mL EmrysTM
reaction vial, barbituric acid 1 (1 mmol), aldehyde 2 (1
mmol), quinolin-6-amine 3 (1 mmol), and and DMF (1.5 mL)
were mixed and then capped. The mixture was irradiated at
150 W and at 110ꢀC for a given time. The reaction mixture
was cooled to room temperature and poured into water (50
mL), filtered to give the crude product, which was further puri-
fied by recrystallization from EtOH.
12-(3-Nitrophenyl)pyrimido[5,4-b][4,7]phenanthroline-9,11
(7H,8H,10H,12H)-dione (4e). This compound was obtained
according to above general procedure; ir (KBr): m3252, 3067,
1714, 1660, 1580, 1551, 1451, 1383, 1263, 1098, 975, 829
12-(4-Fluorophenyl)pyrimido[5,4-b][4,7]phenanthroline-9,11
(7H,8H,10H,12H)-dione (4a). This compound was obtained
according to above general procedure; ir (KBr): m 3207, 3066,
1714, 1655, 1633, 1543, 1471, 1381, 1265, 1093, 976, 862
1
cmꢁ1; H NMR: d 10.75 (s, 1H, NH), 10.63 (s, 1H, NH), 9.44
cmꢁ1 1H NMR: d 10.73 (s, 1H, NH), 10.54(s, 1H, NH),
;
(s, 1H, NH), 8.70 (d, 1H, J ¼ 4.0 Hz, ArH), 8.38 (d, 1H, J ¼
8.4 Hz, ArH), 8.16 (s, 1H, ArH), 7.40–7.98 (m, 2H, ArH),
7.71 (d, 2H, J ¼ 8.8 Hz, ArH), 7.49 (t, 1H, J ¼ 8.0 Hz, ArH),
7.42 (dd, 1H, J ¼ 8.4, 4.0 Hz, ArH), 5.96 (s, 1H, CH). Anal.
calcd for C22H17N3O4: C20H13N5O4: C, 62.01; H, 3.38; N,
18.08; Found C, 62.05; H, 3.40; N, 18.05.
9.32(s, 1H, NH), 8.70 (d, 1H, J ¼ 4.0 Hz, ArH), 8.35 (d, 1H,
J ¼ 8.4 Hz, ArH),7.91–7.96 (m, 1H, ArH), 7.65 (d, 1H, J ¼
8.8 Hz, ArH),7.42 (dd, 1H, J ¼ 8.4, 4.0 Hz, ArH), 7.29 (dd,
2H, J ¼ 7.6, 6.0 Hz, ArH), 7.00 (t, 2H, J ¼ 8.4 Hz, ArH),5.76
(s, 1H, CH). Anal. calcd for C20H13FN4O2: C, 66.66; H, 3.64;
N, 15.55; Found C, 66.70; H, 3.68; N, 15.52.
12-p-Tolylpyrimido[5,4-b][4,7]phenanthroline-9,11(7H,-8H,
10H,12H)-dione (4f). This compound was obtained according
to above general procedure; ir (KBr): m 3193, 3064, 1713,
12-(4-Chlorophenyl)pyrimido[5,4-b][4,7]phenanthroline-9,11
(7H,8H,10H,12H)-dione (4b). This compound was obtained
according to above general procedure; ir (KBr): m 3203, 3065,
1714, 1683, 1634, 1543, 1487, 1381, 1266, 1089, 976, 830
1
1658, 1542, 1470, 1451, 1382, 1266, 1037, 976, 832 cmꢁ1; H
1
cmꢁ1; H NMR: d 10.74 (s, 1H, NH), 10.55 (s, 1H, NH), 9.34
NMR: d 10.65 (s, 1H, NH), 10.43 (s, 1H, NH), 9.22 (s, 1H,
NH), 8.68 (d, 1H, J ¼ 4.0 Hz, ArH), 8.34 (d, 1H, J ¼ 8.4 Hz,
ArH), 7.90 (d, 1H, J ¼ 8.8 Hz, ArH), 7.63 (d, 1H, J ¼ 8.8
Hz, ArH), 7.41 (dd, 1H, J ¼ 8.4, 4.0 Hz, ArH), 7.15 (d, 2H, J
¼ 8.0 Hz, ArH), 6.96 (d, 2H, J ¼ 8.0 Hz, ArH), 5.96 (s, 1H,
CH), 2.15 (s, 3H, CH3). Anal. calcd for C21H16N4O2: C,
70.77; H, 4.53; N, 15.72; Found C, 70.82; H, 4.52; N, 15.74.
12-Phenylpyrimido[5,4-b][4,7]phenanthroline-9,11(7H,-8H,
10H,12H)-dione (4g). This compound was obtained according
to above general procedure; ir (KBr): m 3196, 3067, 1713,
(s, 1H, NH), 8.70 (d, 1H, J ¼ 4.0 Hz, ArH), 8.34 (d, 1H, J ¼
8.4 Hz, ArH), 7.94 (t, 1H, J ¼ 8.4 Hz, ArH), 7.65 (d, 1H, J ¼
8.4 Hz, ArH), 7.42 (dd, 1H, J ¼ 8.4, 4.0 Hz, ArH), 7.29 (d,
2H, J ¼ 8.4 Hz, ArH), 7.23 (d, 2H, J ¼ 8.4 Hz, ArH), 5.76 (s,
1H, CH). Anal. calcd for C20H13ClN4O2: C, 63.75; H, 3.48; N,
14.87; Found C, 63.68; H, 3.50; N, 14.90.
12-(4-Bromophenyl)pyrimido[5,4-b][4,7]phenanthroline-9,11
(7H,8H,10H,12H)-dione (4c). This compound was obtained
according to above general procedure; ir (KBr): m 3201, 3065,
1714, 1656, 1633, 1545, 1484, 1381, 1266, 1099, 976, 829
1
1647, 1599, 1518, 1452, 1382, 1264, 1078, 976, 829 cmꢁ1; H
1
cmꢁ1; H NMR: d 10.74 (s, 1H, NH), 10.57 (s, 1H, NH), 9.39
NMR: d 10.69 (s, 1H, NH), 10.49 (s, 1H, NH), 9.27 (s, 1H,
NH), 8.69–8.70 (m, 1H, ArH), 8.36 (d, 1H, J ¼ 8.4 Hz, ArH),
7.92 (d, 1H, J ¼ 8.8 Hz, ArH), 7.65 (d, 1H, J ¼ 8.8 Hz,
ArH), 7.42 (dd, 1H, J ¼ 8.4, 4.0 Hz, ArH), 7.28 (d, 2H, J ¼
8.8 Hz, ArH), 7.18 (t, 2H, J ¼ 7.6 Hz, ArH), 7.06 (t, 1H, J ¼
7.6 Hz, ArH),5.74 (s, 1H, CH). Anal. calcd for C20H14N4O2:
C, 70.17; H, 4.12; N, 16.37; Found C, 70.23; H, 4.10; N,
16.40.
(s, 1H, NH), 8.70–8.71 (m, 1H, J ¼ 4.0 Hz, ArH), 8.34 (d,
1H, J ¼ 8.8 Hz, ArH), 7.93 (d, 1H, J ¼ 8.8 Hz, ArH), 7.64
(d, 1H, J ¼ 8.8 Hz, ArH),7.42 (dd, 1H, J ¼ 8.4, 4.0 Hz, ArH),
7.36 (d, 2H, J ¼ 8.4 Hz, ArH), 7.23 (d, 2H, J ¼ 8.4 Hz,
ArH), 5.74 (s, 1H, CH). Anal. calcd for C20H13BrN4O2: C,
57.02; H, 3.11; N, 13.30; Found C, 57.07; H, 3.10; N, 13.32.
12-(3,4-Dimethoxyphenyl)pyrimido[5,4-b][4,7]phenanthro-
line-9,11(7H,8H,10H,12H)-dione (4d). This compound was
obtained according to above general procedure; ir (KBr): m
3262, 3068, 1706, 1653, 1554, 1513, 1418, 1382, 1263, 1138,
12-(4-Hydroxy-3-nitrophenyl)pyrimido[5,4-b][4,7]phenan-
throline-9,11(7H,8H,10H,12H)-dione (4h). This compound
was obtained according to above general procedure; ir (KBr):
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet