Med Chem Res (2012) 21:634–641
639
1188, 1150, 966, 869, 769 cm-1
;
1H NMR (300 MHz,
General procedure for the preparation of N-(substituted)
phenyl pongamol pyrazole compounds (3–13)
CDCl3): d 7.90–6.82 (m, H-2 & H-6), 7.57 (br s, H-200),
7.46–7.01 (m, H-60, H-3, H-4, H-5 & 4-Ar–H), 6.88 (m,
H-300 & H-50), 6.73 (s, H-a), 3.67 (s, OMe); 13C NMR
(75 MHz, CDCl3): d 164.2, 160.9, 157.5, 152.0, 150.9,
144.3, 142.6, 141.3, 133.1, 129.6, 129.4, 128.6, 128.0,
127.2, 125.8, 118.7, 115.4, 113.5, 113.2, 111.2, 110.9,
106.9, 106.2, 105.1, 59.2; HRESI-MS calcd for
C24H17FN2O2 [M?H]? 385.1347, found 385.1356.
Pongamol (0.030 g, 1 mmol) was dissolved in glacial acetic
acid (5 ml), and different hydrazine derivatives (1.2 mmol)
(hydrazine hydrate, phenylhydrazine, 3-fluoro phenylhydr-
azine hydrochloride, 2-fluorophenylhydrazine hydrochloride,
4-fluoro phenylhydrazine hydrochloride, 3-nitrophenylhydr-
azine hydrochloride, 2,4-dinitrophenylhydrazine hydrochloride,
2,4-dichlorophenylhydrazine hydrochloride, 4-methoxy-
phenylhydrazine hydrochloride, 2-methylphenylhydrazene
hydrochloride, 2,4-dimethylphenylhydrazene hydrochloride
at 85°C) were added to the solution. The solution was
refluxed for 8 h, and then the solvent was removed in vacuo.
Residue was dissolved in ethyl acetate and washed with
water. Organic portion was collected, dried over sodium
sulfate, and concentrated in vacuo. Crude product was fur-
ther purified by column chromatography. All the products
(3–13) were prepared by using the same procedure.
1-(2-Fluorophenyl)-3-(4-methoxybenzofuran-5-yl)-5-
phenyl-1H-pyrazole (6)
Isolated as a yellow solid. Yield (0.023 g, 60%); mp:
135–136°C; IR (KBr): 1596, 1556, 1509, 1463, 1345,
1
1236, 1067, 963, 762 cm-1; H NMR (300 MHz, CDCl3):
d 7.99 (d, J = 8.6 Hz, H-60), 7.61–7.55 (m, H-200 & H-50),
7.39–7.21 (m, H-2, H-3, H-4, H-5, H-6 & 3-Ar–H),
7.11–7.04 (m, H-a & Ar–H), 6.94 (dd, J = 2.2, 0.9 Hz,
H-300), 4.08 (s, OMe); 13C NMR (75 MHz, CDCl3): d
158.2, 157.1, 154.8, 152.4, 151.0, 144.1, 142.9, 133.2,
129.3, 129.2, 128.8, 128.5, 127.8, 127.0, 125.9, 124.0,
118.6, 116.6, 116.3, 115.3, 106.0, 105.6, 105.0, 59.6;
HRESI-MS calcd for C24H17FN2O2 [M?H]? 385.1347,
found 385.1351.
3-(4-Methoxybenzofuran-5-yl)-5-phenyl-1H-pyrazole (3)
Isolated as a colorless solid (0.022 g, 75%); mp: 129°C; IR
(KBr): 3283, 1725, 1656, 1598, 1545, 1496, 1345, 1284,
1
1230, 1065, 956, 716 cm-1; H NMR (300 MHz, CDCl3):
d 7.95 (d, J = 8.7 Hz, H-60), 7.91–7.83 (m, H-2 & H-6),
7.60 (d, J = 1.9 Hz, H-200), 7.52–7.40 (m, H-3, H-4 &
H-5), 7.32 (d, J = 8.7 Hz, H-50), 7.02 (s, H-a), 6.99 (br s,
H-300), 4.21 (s, OMe); 13C NMR (75 MHz, CDCl3): d
166.9, 162.9, 157.7, 150.9, 144.4, 129.7, 128.9, 128.8,
126.8, 125.7, 124.1, 107.0, 106.7, 105.2, 104.9, 100.6,
100.2, 59.8; HRESI–MS calcd for C18H14N2O2 [M?H]?
291.1128, found 291.1126.
1-(4-Fluorophenyl)-3-(4-methoxybenzofuran-5-yl)-5-
phenyl-1H-pyrazole (7)
Isolated as a yellow solid. Yield (0.026 g, 68%); mp:
139–140°C; IR (KBr): 1641, 1554, 1511, 1465, 1346,
1223, 1151, 1065, 966, 840, 766 cm-1
;
1H NMR
(300 MHz, CDCl3): d 8.01 (d, J = 8.4 Hz, H-60), 7.57 (d,
J = 2.0 Hz, H-200), 7.40–7.22 (m, H-2, H-3, H-4, H-5, H-6,
4 Ar–H), 7.08–7.00 (m, H-50 & H-a), 6.95 (s, H-300), 4.09
(s, OMe); 13C NMR (75 MHz, CDCl3): d 157.4, 156.7,
144.3, 144.0, 128.8, 128.6, 128.5, 128.2, 127.8, 127.3,
126.9, 126.8, 125.8, 125.5, 125.4, 125.3, 115.8, 115.5,
115.2, 108.8, 107.0, 106.4, 106.2, 105.1, 104.9, 60.4, 59.3;
HRESI-MS calcd for C24H17FN2O2 [M?H]? 385.13547,
found 385.1354.
3-(4-Methoxybenzofuran-5-yl)-1,5-diphenyl-1H-pyrazole (4)
Isolated as a colorless solid. Yield (0.024 g, 65%); mp:
156–157°C; IR (KBr): 3285, 3237, 1657, 1545, 1497,
;
1437, 1371, 1303, 1239, 997, 755 cm-1 1H NMR
(300 MHz, CDCl3): d 7.93–7.88 (m, H-2 & H-6), 7.55 (d,
J = 2.3 Hz, H-200), 7.43–7.15 (m, H-60, H-50, H-3, H-4,
H-5, & 5–Ar–H), 6.84 (d, J = 2.0 Hz, H-300), 6.74 (s, H-a),
3.62 (s, OMe); 13C NMR (75 MHz, CDCl3): d 157.3,
151.6, 150.8, 144.2, 141.3, 140.8, 133.2, 128.6 (3C), 128.5
(3C), 127.7, 127.3, 126.7, 125.7 (2C), 123.6 (2C), 106.4,
105.9, 105.0, 59.2; HRESI-MS calcd for C24H18N2O2
[M?H]? 367.1441, found 367.1443.
3-(4-Methoxybenzofuran-5-yl)-1-(3-nitrophenyl)-5-
phenyl-1H-pyrazole (8)
Isolated as a yellow viscous liquid. Yield (0.018 g, 45%);
IR (KBr): 1659, 1588, 1525, 1483, 1353, 1254, 1151, 1037,
1
943, 735 cm-1; H NMR (300 MHz, CDCl3): d 8.36 (t,
1-(3-Fluorophenyl)-3-(4-methoxybenzofuran-5-yl)-5-
J = 2.2 Hz, Ar–H). 8.05 (qd, J = 1.1, 2.0, 3.0 Hz, Ar–H),
7.92 (m, H-2 & H-6), 7.60 (m, H-200 & Ar–H), 7.47–7.30
(m, H-3, H-4, H-5, 2 Ar–H), H-60 & H-50), 6.86 (dd,
J = 2.2, 0.9 Hz, H-300), 6.77 (s, H-a), 4.10 (s, OMe); 13C
NMR (75 MHz, CDCl3): d 156.9, 151.4, 150.4, 148.5,
phenyl-1H-pyrazole (5)
Isolated as a yellow solid. Yield (0.025 g, 65%); mp:
138°C; IR (KBr): 1691, 1612, 1492, 1462, 1344, 1231,
123