Chemistry
All chemicals and solvents used in this study were purchased from Merck (Darmstadt, Germany) and Sigma-Aldrich (San Louis, MO, USA). Melting points were determined on a Kofler hot stage apparatus and are uncorrected. The IR spectra were obtained on a Shimadzu 470 spectrophotometer (potassium bromide disks).
1H-NMR spectra were measured using a Bruker FT-500 spectrometer, and chemical shifts are expressed as d (ppm) with tetramethylsilane as internal standard. The mass spectra were run on a Finnigan TSQ-70 spectrometer at 70 eV. Merck silica gel 60 F254 plates were used for analytical TLC; column chromatography was performed on Merck silica gel (70–230 mesh). Yields were calculated for purified products and were not optimized.
Typical Procedure for synthesis of 7-Aryl-10, 11-dihydro-9H-chromeno[4,3-b]quinoline-6,8-dione (2)
Compounds 1 (5.4 mmol), sodium nitrite (16 mmol, 1.1 g) and silica sulfuric acid (1.6 g) and silica (1.07 g) were refluxed in chloroform (100 mL) for 8-12 h. The mixture was cooled to room temperature and was filtered. The filtrate was evaporated to dryness under reduced pressure, and the crude product was purified by short column chromatography to give 2 (
Table 1).
7-(2-Methylphenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2a).
Yellowish solid 1.36 g (yield 71%), mp = 210-212 °C, Rf = 0.70 (2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 2922, 2848 (C-H aliphatic), 1754 (C = O ester), 1691 (C = O ketone), 757 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.02 (s, 3H, CH3 ), 2.24 (qn, 2H, J = 6.6 Hz, H10), 2.66 (t, 2H, J = 6.6 Hz, H9), 3.38 (t, 2H, J = 6.6 Hz, H11), 6.81 (d, 1H, J = 7.0 Hz, H15 ), 7.23 (t, 1H, J = 7.0 Hz, H17), 7.28-7.35 (m, 3H, H16, H18, H4), 7.40 (t, 1H, J = 8.0 Hz, H2), 7.61 (t, 1H, J = 8.0 Hz, H3), 8.68 (d, 1H, J = 8.0 Hz, H1).
13CNMR (CDCl3), δ: 20.01, 20.98, 34.61, 40.13, 115.13, 116.90, 118.83, 124.61, 124.89, 125.58, 126.09, 127.44, 127.69, 129.26, 133.33, 134.24, 137.84, 153.43, 154.13, 156.39, 157.92, 169.58, 196.14.
MS : m/z (%), 355 (M+, 44), 340 (44), 327 (37), 299(100), 271(37), 151(50), 126 (50), 114 (63), 100 (44), 87 (25).
Anal. Calcd for C23H17NO3: C, 77.73; H, 4.82; N, 3.94. Found: C, 77.40 ; H, 4.56; N, 3.95.
7-(3-Methylphenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2b).
White solid, 1.22 g (yield 64%), mp = 172-174 °C, Rf = 0.73 (2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 2848 (C-H aliphatic), 1754 (C=O ester), 1691(C=O ketone), 757 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.24 (qn, 2H, J = 6.6 Hz, H10), 2.39 (s, 3H, CH3 ), 2.67 (t, 2H, J = 6.5 Hz, H9), 3.36 (t, 2H, J = 6.5 Hz, H11), 6.91 (m, 2H, H14, H16 ), 7.24 (d, 1H, J = 7.5 Hz, ), 7.30 (d, 1H, J = 8.0 Hz, H4), 7.33 (t, 1H, J = 7.5 Hz, H17), 7.39 (t, 1H, J = 8.0 Hz, H2), 7.60 (t, 1H, J = 8.0 Hz, H3), 8.67 (d, 1H, J = 8.0 Hz, H1).
13CNMR (CDCl3), δ: 20.93, 21.64, 34.56, 40.33, 115.08, 116.83, 118.80, 123.34, 124.56, 125.67, 126.11, 126.78, 127.74, 128.41, 133.25, 133.40, 137.35, 153.41, 153.86, 156.60, 158.13, 169.29, 196.39.
MS : m/z (%), 355 (M+, 48), 340 (38), 265 (38), 149 (86), 121 (100), 105 (23), 92 (35), 71 (35), 57 (42), 43 (50).
Anal. Calcd for C23H17NO3: C, 77.73; H, 4.82; N, 3.94. Found: C, 77.80; H, 4.85; N, 3.97.
7-(4-Methylphenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2c).
White solid, 1.30 g (yield 68%) mp = 241-243 °C, Rf= 0.74 (2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 3033 (C-H aromatic), 2853 (C-H aliphatic), 1750 (C=O ester), 1698 (C=O ketone), 759 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.24 (qn, 2H, J = 6.6 Hz, H10), 2.46 (s, 3H, CH3 ), 2.68 (t, 2H, J = 6.6 Hz, H9), 3.37 (t, 2H, J = 6.3 Hz, H11), 7.02 (d, 2H, J = 8.0 Hz, H15, H17), 7.27 (d, 2H, J = 8.0 Hz, H14, H18), 7.32 (d, 1H, J = 8.2 Hz, H4), 7.41 (t, 1H, J = 8.2 Hz, H2), 7.61 (t, 1H, J = 8.2 Hz, H3), 8.68 (d, 1H, J = 8.2 Hz, H1).
13CNMR (CDCl3), δ: 20.94, 21.57, 34.54, 40.33, 115.19, 116.86, 118.84, 124.56, 126, 11, 126.15, 127.94, 128.75, 133.24, 134.93, 137.19, 153.42, 153.89, 156.67, 158.25, 169.27, 196.58.
MS : m/z (%), 355 (M+, 100), 340 (31), 327 (25), 299 (19), 127 (13).
Anal. Calcd for C23H17NO3: C, 77.73; H, 4.82; N, 3.94. Found: C, 77.68 ; H, 4.78; N, 3.90.
7-(2-Methoxyphenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione(2d).
White solid, 1.42 g (yield 71%), mp = 180-182 °C, Rf = 0.69 (2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 3056 (C-H aromatic), 2852 (C-H aliphatic), 1749 (C=O ester), 1693 (C=O ketone), 753 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.25 (qn, 2H, J = 6.7 Hz, H10), 2.69 (t, 2H, J = 6.7 Hz, H9), 3.38 (t, 2H, J = 6.7 Hz, H11), 3.74 (s, 3H, OCH3 ), 6.90 (d, 1H, J =6.0 Hz, H15 ), 6.89 (d, 1H, J =6.0 Hz, H18 ), 7.00 (m, 1H, H17), 7.31 (d, 1H, J = 8.2 Hz, H4), 7.41 (t, 1H, J =6.0 Hz, H16 ), 7.43 (t, 1H, J =8.2 Hz, H2 ), 7.61 (t, 1H, J = 8.2 Hz, H3), 8.68 (d, 1H, J = 8.2 Hz, H1).
13CNMR (CDCl3), δ: 20.97, 34.48, 40.06, 55.67, 110.39, 115.60, 116.82, 118.97, 120.73, 124.49, 126.04, 126.76, 127.40, 128.07, 129.21, 133.08, 153.32, 153.51, 153.87, 155.85, 158.13, 169.18, 196.28.
MS : m/z (%), 371 (M+, 38), 340 (100), 120 (31), 91 (31), 75 (25).
Anal. Calcd for C23H17NO4: C, 74.38; H, 4.61; N, 3.77. Found: C, 74.32 ; H, 4.58; N, 3.70.
7-(3-Methoxyphenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2e).
White solid, 1.32 g (yield 66%), mp = 155-157 °C, Rf = 0.67 (2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 3060 (C-H aromatic), 2835 (C-H aliphatic), 1755 (C=O ester), 1692 (C=O ketone), 766 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.25 (qn, 2H, J = 6.5 Hz, H10), 2.68 (t, 2H, J = 6.5 Hz, H9), 3.37 (t, 2H, J = 6.5 Hz, H11), 3.82 (s, 3H, OCH3 ), 6.67 (s, 1H, H14 ), 6.72 (d, 1H, J = 7.5 Hz, H18), 6.98 (d, 1H, J = 7.5 Hz, H16), 7.31 (d, 1H, J = 8.0 Hz, H4), 7.37-7.42 (m, 2H, H17, H2), 7.61 (t, 1H, J = 8.0 Hz, H3), 8.68 (d, 1H, J = 8.0 Hz, H1).
13CNMR (CDCl3), δ: 20.91, 34.56, 40.29, 55.13, 112.49, 112.56, 115.02, 116.86, 118.76, 124.57, 126.11, 127.62, 128.97, 133.29, 133.89, 139.26, 153.41, 153.91, 155.96, 157.97, 159.33, 169.35, 196.17.
MS : m/z (%), 371 (M+, 44), 340 (37), 341 (50), 196 (63), 120 (38), 91 (100), 43 ( 50).
Anal. Calcd for C23H17NO4: C, 74.38; H, 4.61; N, 3.77. Found: C, 74.33; H, 4.56; N, 3.68.
7-(4-Methoxyphenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione(2f).
White solid, 1.50 g (yield 75%), mp = 185-187 °C, Rf = 0.71 ( 2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 2854(C-H aliphatic), 1747(C=O ester), 1688(C=O ketone), 761(C-H bending).
1HNMR (CDCl3), δ (ppm): 2.24 (qn, 2H, J = 6.6 Hz H10), 2.69 (t, 2H, J = 6.5 Hz, H9), 3.37 (t, 2H, J = 6.4 Hz, H11), 3.88 (s, 3H, OCH3 ), 7.00 (d, 2H, J = 8.7 Hz, H15, H17), 7.05 (d, 2H, J = 8.7 Hz, H14, H18), 7.32 (d, 1H, J = 8.2 Hz, H4), 7.41 (t, 1H, J = 8.2 Hz, H2), 7.62 (t, 1H, J = 8.2 Hz, H3), 8.68 (d, 1H, J = 8.2 Hz, H1).
13CNMR (CDCl3-d), δ: 20.94, 34.54, 40.38, 55.11, 113.51, 115.29, 116.84, 118.85, 124.56, 126.12, 127.73, 128.11, 129.89, 130.03, 133.23, 153.40, 153.89, 156.37, 158.33, 169.25, 196.70.
MS : m/z (%), 371 (M+, 11), 289 (18), 149 29), 121 (32), 85 (63), 71 (88), 57 (100), 43 (95).
Anal. Calcd for C23H17NO4: C, 74.38; H, 4.61; N, 3.77. Found: C, 74.43 ; H, 4.59; N, 3.69.
7-(2-Cholorophenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2g).
White solid, 1.33 g (yield 66%), mp = 253-255 °C, Rf= 0.65 (2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 3068 (C-H aromatic), 2854 (C-H aliphatic), 1744 (C=O ester), 1690 (C=O ketone), 762 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.27 (qn, 2H, J = 6.5 Hz, H10), 2.69 (t, 2H, J = 6.5 Hz, H9), 3.41 (t, 2H, J = 6.5 Hz, H11), 7.03 (d, 1H, J = 7.8 Hz, H18), 7.27-7.43 (m, 4H, H2, H4, H16, H17), 7.50 (d, 1H, J = 7.8 Hz, H15), 7.62 (t, 1H, J = 7.8 Hz, H3), 8.70 (d, 1H, J = 7.8 Hz, H1).
13CNMR (CDCl3), δ: 20.88, 34.55, 39.89, 114.97, 116.94, 118.75, 124.68, 126.08, 126.68, 127.09, 127.18, 128.92, 130.77, 133.42, 133.90, 137.28, 152.92, 153.38, 154.26, 157.99, 169.69, 196.94.
MS : m/z (%),377 (M++2, 33), 375 (M+, 100), 340 (25), 187 (13), 127 (13), 113 (13), 100 (10), 87 (5).
Anal. Calcd for C22H14ClNO3: C, 70.31; H, 3.75; N, 3.73. Found: C, 70.40 ; H, 3.69; N, 3.70.
7-(3-Cholorophenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2h).
White solid, 1.37 g (yield 68%), mp = 188-190 °C, Rf= 0.64 (2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 3018 (C-H aromatic), 2853 (C-H aliphatic), 1744 (C=O ester), 1691 (C=O ketone), 757 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.23-2.28 (qn, 2H, J = 6.5 Hz, H10), 2.67-2.70 (t, 2H, J = 6.5 Hz, H9), 3.39-3.40 (t, 2H, J = 6.5 Hz, H11), 7.02 (d, 1H, J = 7.0 Hz, H16 ), 7.10 (s, 1H, H14), 7.30 (d, 1H, J = 8.0 Hz, H4), 7.37-7.42 (m, 3H, H2, H17, H18), 7.62 (t, 1H, J = 8.0 Hz, H3), 8.68 (d, 1H, J = 8.0 Hz, H1).
13CNMR (CDCl3) δ: 20.85 (C10), 34.57 (C11), 40.24 (C9), 114.86 (C7), 116.88 (C4), 118.64 (C1a), 124.59 (C16), 124.72 (C2), 126.15 (C1), 126.27 (C14), 127.26 (C7a), 127.62 (C17), 129.16 (C18), 133.49 (C3), 133.90 (C13), 139.79 (C6a), 153.38 (C12a), 154.04 (C4a), 154.48 (C15), 158.07 (C6), 169.64 (C11a), 196.08 (C8).
MS : m/z (%), 377 (M++2, 10), 375 (M+, 30), 340 (30), 319 (27), 289 (14), 227 (44), 127 (44), 120 (100), 100 (64), 87 (32), 74 (36).
Anal. Calcd for C22H14ClNO3: C, 70.31; H, 3.75; N, 3.73. Found: C, 70.38; H, 3.56; N, 3.67.
7-(4-Cholorophenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2i).
White solid, 1.41 g (yield 70%), mp = 281-283 °C, Rf = 0.66 (2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 2851 (C-H aliphatic), 1745 (C=O ester), 1691 (C=O ketone), 753 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.25 (qn, 2H, J = 6.6 Hz H10), 2.68 (t, 2H, J = 6.6 Hz, H9), 3.38 (t, 2H, J = 6.6 Hz, H11), 7.05 (d, 2H, J = 8.3 Hz, H14, H18), 7.33 (d, 1H, J = 8.2 Hz, H4), 7.41(d, 1H, J = 8.2 Hz, H2), 7.43 (d, 2H, J = 8.3 Hz, H15, H17), 7.62 (t, 1H, J = 8.2 Hz, H3), 8.68 (d, 1H, J = 8.2 Hz, H1).
13CNMR (CDCl3), δ: 20.87, 34.56, 40.28, 114.85, 116.90, 118.62, 124.70, 126.16, 126.25, 127.64, 128.29, 133.47, 133.88, 136.46, 153.39, 154.07, 155.15, 158.08, 169.55, 196.34.
MS : m/z (%), 377 (M+ +2, 10), 375 (M+, 29), 289 (100), 265 (58), 237 (64), 121 (100), 85 (44), 71 (59), 57 (80).
Anal. Calcd for C22H14ClNO3: C, 70.31; H, 3.75; N, 3.73. Found: C, 70.28 ; H, 3.70; N, 3.70.
7-(3-Nitrophenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2j).
White solid, 1.45 g (yield 70%), mp = 161-163 °C, Rf = 0.64 (2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 3086 (C-H aromatic), 2849 (C-H aliphatic), 1748 (C=O ester), 1693 (C=O ketone), 1543, 1343 (N=O nitro aryl), 765 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.28 (qn, 2H, J = 6.6 Hz, H10), 2.68 (t, 2H, J = 6.6 Hz, H9), 3.39 (t, 2H, J = 6.6 Hz, H11), 7.33 (d, 1H, J = 8.0 Hz, H4), 7.42-7.48 (m, 2H, H2, H17), 7.61-7.66 (m, 2H, H3, H18), 7.98 (s, 1H, H14), 8.31 (d, 1H, J = 7.75 Hz, H16), 8.70 (d, 1H, J = 8.0 Hz, H1).
13CNMR (CDCl3δ
MS : m/z (%), 386 (M+, 30), 289 (37), 167 (62.5), 149 (51), 121 (29), 77 (98), 43 (100).
Anal. Calcd for C23H17NO3: C, 77.73; H, 4.82; N, 3.94. Found: C, 77.69 ; H, 4.80; N, 3.86.
7-(4-Nitrophenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2k).
White solid, 1.39 g (yield 67%), mp = 265-267 °C, Rf = 0.63(2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 3072 (C-H aromatic), 2951, 2849 (C-H aliphatic), 1741 (C=O ester), 1689 (C=O ketone), 1547, 1346 (N=O nitro aryl), 765 (C-H bending).
1HNMR (CDCl3), δ(ppm): 2.25 (qn, 2H, J = 6.4 Hz, H10), 2.68 (t, 2H, J = 6.4 Hz, H9), 3.39 (t, 2H, J = 6.4 Hz, H11), 7.30 (d, 2H, J = 8.6 Hz, H14, H18), 7.33 (d, 1H, J = 8.2 Hz, H4), 7.43 (t, 1H, J = 8.0 Hz, H2), 7.64 (t, 1H, J = 8.0 Hz, H3), 8.31 (d, 2H, J = 8.6 Hz, H15, H17), 8.70 (d, 1H, J = 8.0 Hz, H1).
13δ
MS : m/z (%),386 (M+, 12.5), 289(34), 265(18), 121(80), 84(100), 57(75).
Anal. Calcd for C23H17NO3: C, 77.73; H, 4.82; N, 3.94. Found: C, 77.80; H, 4.92; N, 3.89.
7-(3-Bromophenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2l).
White solid, 1.44 g (yiled 64%), mp = 184-186 °C, Rf = 0.72 ( 2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 3070 (C-H aromatic), 2954 (C-H aliphatic), 1748 (C=O ester), 1693 (C=O ketone), 768 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.25 (qn, 2H, J = 6.5 Hz, H10), 2.69 (t, 2H, J = 6.5 Hz, H9), 3.39 (t, 2H, J = 6.5 Hz, H11), 7.08 (d, 1H, J = 7.6 Hz, H16), 7.24 (s, 1H, H14), 7.32, 7.35 (m, 2H, H4, H17), 7.41 (t, 1H, J = 8.0 Hz, H2), 7.58 (d, 1H, J = 7.6 Hz, H18), 7.64 (t, 1H, J = 8.0 Hz, H3), 8.68 (d, 1H, J = 8.0 Hz, H1).
13CNMR (CDCl3), δ: 20.85, 34.58, 40.24, 114.88, 116.91, 118.64, 122.04, 124.71, 125.03, 126.16, 127.22, 128.96, 129.38, 130.52, 133.50, 140.01, 153.40, 154.08, 154.40, 158.08, 169.61, 196.06.
MS : m/z (%), 421 (M+ +2, 98), 419 (100), 340 (33), 312 (68), 169 (80), 155 (38), 127 (67), 113 (70), 100 (60), 87 ( 47).
Anal. Calcd for C22H14BrNO3: C, 62.87; H, 3.36; N, 3.33. Found: C, 62.78 ; H, 3.29; N, 3.40.
7-(4-Bromophenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2m).
White solid, 1.47 g (yiled 65%), mp = 279-281 °C Rf = 0.77 ( 2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 3042 (C-H aromatic), 2922 (C-H aliphatic), 1745 (C=O ester), 1693 (C=O ketone), 771 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.24 (qn, 2H, J = 6.5 Hz, H10), 2.67 (t, 2H, J = 6.5 Hz, H9), 3.38 (t, 2H, J = 6.4 Hz, H11), 6.98 (d, 2H, J = 8.3 Hz, H14, H18), 7.32 (d, 1H, J = 7.0 Hz, H4), 7.40 (t, 1H, J = 7.0 Hz, H2), 7.58 (d, 2H, J = 8.3 Hz, H15, H17), 7.62 (t, 1H, J = 70 Hz, H3), 8.67 (d, 1H, J = 7.0 Hz, H1). 13CNMR (CDCl3), δ: 20.87, 34.56, 40.28, 114.92, 116.91, 118.68, 124.71, 126.16, 126.26, 127.40, 127.91, 131.19, 133.48, 136.99, 153.39, 154.08, 155.10, 158.23, 169.57, 196.34.
MS : m/z (%), 421 (M+ +2, 11), 419 (M+, 11), 330 (13), 289 (100), 216 (22), 149 (20), 83 (31), 57 (76).
Anal. Calcd for C22H14BrNO3: C, 62.87; H, 3.36; N, 3.33. Found: C, 62.79 ; H, 3.37; N, 3.40.
7-(Phenyl)-10, 11-dihydro-6H-chromeno[4, 3-b]quinoline-6, 8-dione (2n).
Yellowish solid, 1.36 g (yield 74%), mp = 121-123 °C, Rf = 0.79 (2:8 EtOAc/Petrolum Ether).
νmax cm-1(KBr): 3056 (C-H aromatic), 2949 (C-H aliphatic), 1744 (C=O ester), 1693 (C=O ketone), 776 (C-H bending).
1HNMR (CDCl3), δ (ppm): 2.25 (qn, 2H, J = 6.6 Hz, H10), 2.68 (t, 2H, J = 6.6 Hz, H9), 3.38 (t, 2H, J = 6.6 Hz, H11), 7.13 (m, 2H, H14, H18 ), 7.32 (d, 1H, J = 8.0 Hz, H4), 7.42 (t, 1H, J = 8.0 Hz, H2), 7.46 (m, 3H, H15, H16, H17), 7.61 (t, 1H, J = 8.0 Hz, H3), 8.68 (d, 1H, J = 8.0 Hz, H1).
13CNMR (CDCl3), δ: 20.91, 34.57, 40.30, 115.06, 116.87, 118.80, 124.59, 124.75, 126.13, 126.16, 127.56, 127.92, 133.30, 138, 153.43, 153.95, 156.38, 158.19, 169.38, 196.36.
MS : m/z (%), 341 (M+, 81), 313 (69), 289 (38), 196 (44), 120 (75), 90 (100), 76 (44).
Anal. Calcd for C22H15NO3: C, 77.41, H, 4.43; N, 4.10. Found: C, 77.39; H, 4.40; N, 4.09.
Pharmacology
RPMI 1640, fetal bovine serum (FBS), trypsin and phosphate buffered saline (PBS) were purchased from Biosera (Ringmer, UK). 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) was obtained from Sigma-Aldrich (Saint Louis, MO, USA) and penicillin/streptomycin was purchased from Invitrogen (San Diego, CA, USA). Doxorubicin and dimethyl sulphoxide were obtained from EBEWE Pharma (Unterach, Austria) and Merck (Darmstadt, Germany), respectively.
Cell lines and Maintenance of human cell lines
K562 (human chronic myelogenous leukemia), LS180 (human colon adenocarcinoma) and MCF-7 (human breast adenocarcinoma) cells μ2 and were grown in monolayer cultures, except for K562 cells, which were grown in suspension.
MTT-based Cytotoxicity assay
Cell viability following exposure to synthetic compounds was estimated by using the MTT reduction assay (
19-
20). K562 and LS180 cells were plated in 96-well microplates at a density of 5 × 10
4 cells/mL (100 μL per well), While MCF-7cells were plated at densities of 3 × 10
5. Control wells contained no drugs and blank wells contained only growth medium for background correction. After overnight incubation at 37 °C, half of the growth medium was removed and 50 μL of medium supplemented with 3 different concentrations of synthetic were added in duplicate. Plates with K562 cells were centrifuged before this procedure. Compounds were all first dissolved in DMSO and then diluted in the growth medium. The maximum concentration of DMSO in the wells was 0.5%. Cells were further incubated for 72 h and at the end of the incubation time; the medium was replaced with fresh medium containing 0.5 mg/mL of MTT. Plates were incubated for another 4 h at 37 °C. Then the formazan crystals formed in the cells dissolved in 200 μL DMSO. The optical density was measured at 570 nm with background correction at 655 nm using a Bio-Rad microplate reader (Model 680). The percentage inhibition of viability for each concentration of compound was calculated compared to the control wells and IC
50±
Conformational study
The chemical structure of molecules was constructed using Hyperchem (Version 7, Hypercube Inc., http://www.hyper.com, USA). The Z-matrices of the structures were provided by the software and were then transferred to the Gaussian 98 program (
21). Complete geometry optimization was performed taking the most extended conformations as starting geometries. Semi empirical molecular orbital calculations (AM
1) of the structures were performed using Gaussian 98 program. Then we calculated some important dihedral angles of this optimized structure such as orientation of C
7-aryl substitute and conformation of cyclohexenone ring.