synthesis of 4-phenacylidene flavene derivatives from readily available salicylaldehydes and acetophenones, using a mild catalyst at room temperature. The reaction conditionis simple and transformation is quite effective for a widerange of salicylaldehyde and acetophenone derivatives. The protocol is blessed with several advantages like one-pot, good yield, use of environment friendly catalyst, mild reaction condition and atom economy.
Part A: Chapter III
Experimental section
Experimental
General procedure for the synthesis of 4-phenacylidene flavene derivatives (10):
A mixture of salicylaldehyde (1 mmol), acetophenone (2 mmol), and BDMS (0.2 mmol) in CH3CN (3 mL) was stirred at room temperature for 2-7 h in 25 mL round bottomed flask. The progress of the reaction was monitored by TLC (eluent: EtOAc-hexane, 1:9). After the completion of the reaction, the crude reaction mixture was extracted with EtOAc (2 × 10 mL), the combined organic layers were washed with H2O (10 mL), and dried (Na2SO4). The solvent was removed in vacuo and the residue was chromatographed on silica gel (60–120 mesh, eluent: EtOAc-hexane, 1:9) to afford the pure products in 64-91%yields.
(E)-1-(4-chlorophenyl)-2-(2-(4-chlorophenyl)-4H-chromen-4-ylidene)ethanone (10a):
Yellow solid, mp 170-172 °C; IR(KBr): 2923, 2853, 1743, 1640, 1092, 754 cm-1; 1H NMR (400 MHz, CDCl3): δ = 8.90 (s, 1H), 8.01- 7.88 (m, 5H), 7.55 (d, J = 7.2 Hz, 1H), 7.50-7.30 (m, 6H), 7.08 (s, 1H); 13C NMR (150 MHz, CDCl3): δ = 189.1, 155.3, 153.1, 142.8, 139.8, 138.1, 136.9, 132.2, 131.2, 129.3, 129.2, 128.9, 127.5, 125.4, 123.4, 120.5, 118.8, 103.3, 103.1; MS (ESI): [M + H+], Calcd. For:
C23H1535.5Cl2O2 (394.0341); Found: 394.0429.
(E)-1-phenyl-2-(2-phenyl-4H-chromen-4-ylidene)ethanone (10b):
Yellow solid, mp 129-130 °C; IR (KBr): 1700, 1635, 1533, 1263, 752 cm-1; 1H NMR (400 MHz, CDCl3): δ = 8.96 (s, 1H), 8.03 (t, J = 8.0 Hz, 4H), 7.96 (d, J = 8.4 Hz, 1H), 7.56 (t, J = 8.0 Hz, 2H), 7.47 (d, J = 5.2 Hz, 6H), 7.34 (t, J = 8.0 Hz, 1H), 7.15 (s, 1H);13C NMR (150 MHz, CDCl3): δ = 190.5, 156.2, 153.2, 142.6, 141.5, 132.7, 131.9, 131.8, 130.7, 128.9, 128.6, 127.9, 126.2, 125.2, 123.3, 120.6, 118.7, 103.3, 103.1; MS (ESI): [M+ H+], Calcd. For: C23H17O2 (325.1184); Found:
325.1163.
Part A: Chapter III
Experimental section
(E)-1-(4-nitrophenyl)-2-(2-(4-nitrophenyl)-4H-chromen-4-ylidene)ethanone (10c):
Red solid, mp 202-204 °C; IR (KBr): 2997, 2914, 1690, 1601, 1518, 1341, 1203, 1003, 854, 748 cm-1; 1H NMR (400 MHz, CDCl3): δ = 9.08 (s, 1H), 8.36 (t, J = 7.2 Hz, 4H), 8.17 (t, J = 8.8 Hz, 4H), 8.04 (d, J = 8.0 Hz, 1H), 7.65 (t, J = 7.2 Hz, 1H), 7.50 (d, J = 8.0 Hz, 1H), 7.42 (t, J = 8.0 Hz, 1H), 7.17 (s, 1H); MS (ESI): [M + H+], Calcd. For: C23H15N2O6
(415.0885); Found: 415.0871.
(E)-1-(3-nitrophenyl)-2-(2-(3-nitrophenyl)-4H-chromen-4-ylidene)ethanone (10d):
Yellow solid, mp 248-249 °C; IR (KBr): 2923, 2852, 1734, 1638, 1546, 1527, 1347, 1021, 728 cm-1; 1H NMR(400 MHz, CDCl3): δ =9.05 (s, 1H), 8.85 (s, 2H), 8.40 (d, J = 7.6 Hz, 1H ), 8.35 (t, J = 8.0 Hz, 3H), 8.07 (d, J = 8.0 Hz, 1H), 7.74-7.67 (m, 2H), 7.65 (d, J = 7.2 Hz, 1H), 7.53 (d, J = 8.4 Hz, 1H), 7.43 (t, J = 8.0 Hz, 1H), 7.18 (s, 1H); MS (ESI): [M+
H+], Calcd. For: C23H15N2O6 (415.0885); Found: 415.0756.
(E)-1-(p-tolyl)-2-(2-(p-tolyl)-4H-chromen-4-ylidene)ethanone (10e):
Yellow solid, mp 147-149 °C;IR (KBr): 2920, 1730, 1633, 1536, 1265, 1004, 756 cm-1; 1H NMR (400 MHz, CDCl3): δ = 8.94 (s, 1H), 8.02 (d, J = 8.0 Hz, 1H), 7.97-7.90 (m, 4H), 7.56 (t, J = 8.0 Hz, 1H), 7.43 (d, J = 8.0 Hz, 1H), 7.35 (d, J = 8.0 Hz, 1H), 7.29 (d, J = 8.0 Hz, 5H), 2.43 (s, 6H); 13C NMR (100 MHz, CDCl3): δ = 190.0, 156.2, 153.0, 142.7, 142.2, 141.0, 138.8, 131.7, 130.7, 129.6, 129.2, 127.9, 126.0, 125.0, 123.2, 120.5, 118.6, 102.7, 102.4, 21.8, 21.7; MS (ESI):
[M+ H+], Calcd. For: C25H21O2 (353.1536); Found: 353.1536.
Part A: Chapter III
Experimental section
(E)-1-(4-methoxyphenyl)-2-(2-(4-methoxyphenyl)-4H-chromen-4-ylidene)ethanone (10f):
Yellow solid, mp 168-170 °C; IR (KBr): 2925, 2837, 1685, 1640, 1603, 1532, 1251, 1170, 1004, 758 cm-1; 1H NMR (400 MHz, CDCl3):
δ = 8.87 (s, 1H), 8.04 (d, J = 8.4 Hz, 3H), 7.95(d, J = 8.0 Hz, 2H), 7.58- 7.49 (m, 1H), 7.39 (d, J = 9.2 Hz, 1H), 7.36-7.29 (m, 1H), 7.10 (s, 1H), 6.98 (d, J = 7.6 Hz, 4H), 3.89 (s, 6H);13C NMR (100 MHz, CDCl3): δ
= 188.8, 162.3, 161.4, 155.6, 152.8, 142.1, 134.1, 131.3, 129.7, 127.5, 124.9, 124.7, 122.9, 120.4, 118.3, 113.9, 113.6, 102.0, 101.4, 55.3;MS (ESI): [M + H+], Calcd. For: C25H21O4 (385.1395); Found: 385.1397.
(E)-1-(thiophen-2-yl)-2-(2-(thiophen-2-yl)-4H-chromen-4-ylidene)ethanone (10g):
Yellow solid, mp 138-139 °C; IR (KBr): 2924, 1630, 1537, 1263, 977, 758 cm-1; 1H NMR (400 MHz, CDCl3): δ = 8.74 (s, 1H), 7.92 (d, J = 8.0 Hz, 1H), 7.76 (d, J = 3.6 Hz, 1H), 7.68 (d, J = 3.6 Hz, 1H), 7.53 (d, J = 4.8 Hz, 1H), 7.49 (t, J = 7.2 Hz, 1H), 7.44 (d, J = 5.2 Hz, 1H), 7.35- 7.26 (m, 2H), 7.13-7.09 (m, 2H), 6.94 (s, 1H); 13C NMR (100 MHz, CDCl3): δ = 181.8, 152.2, 151.5, 148.5, 141.5, 136.0, 131.8, 131.6, 129.1, 128.6, 127.9, 127.8, 126.9, 124.9, 122.9, 119.6, 118.1, 101.9, 101.7; MS (ESI): [M + H+], Calcd. For: C19H13O2S2 (337.0312); Found: 337.0348.
(E)-2-(8-ethoxy-2-phenyl-4H-chromen-4-ylidene)-1-phenylethanone (10h):
Yellow solid, mp 155-156 °C;IR (KBr): 2924, 1690, 1632, 1571, 1532, 1283, 1222, 1150, 1065, 765 cm-1; 1H NMR (600 MHz, CDCl3): δ = 8.99 (s, 1H), 8.05-8.00 (m, 4H), 7.54-7.45 (m, 7H), 7.21 (t, J = 7.8 Hz, 1H), 7.09 (s, 1H), 7.04 (d, J = 8.4 Hz, 1H), 4.19 (q, J = 4.4 Hz, 2H), 1.54 (t, J = 7.2 Hz, 3H); 13C NMR (150 MHz, CDCl3):
δ = 190.5, 148.9, 143.0, 141.7, 132.9, 131.7, 130.7, 128.9, 128.7, 128.6, 128.4, 127.9, 126.3, 124.7, 121.6, 114.6, 114.2, 103.4, 102.9, 65.2, 15.1; MS (ESI): [M + H+], Calcd. For: C25H21O3 (369.1446); Found: 369.1432.
Part A: Chapter III
Experimental section
(E)-2-(8-ethoxy-2-(4-fluorophenyl)-4H-chromen-4-ylidene)-1-(4-fluorophenyl)ethanone (10i):
Yellow solid, mp 159-160 °C; IR (KBr): 2977, 1637, 1602, 1527, 1506, 1333, 1273, 1219, 1156, 1067, 783 cm-1; 1H NMR (400 MHz, CDCl3): δ = 8.90 (s, 1H), 8.05-8.01 (m, 4H), 7.51 (d, J = 8.4 Hz, 1H), 7.23 (d, J = 7.6 Hz, 1H), 7.19 (d, J = 4.4 Hz, 1H), 7.14 (t, J = 8.8 Hz, 3H), 7.06 (s, 1H ), 7.03 (d, J = 4.0 Hz, 1H), 4.19 (q, J = 6.8 Hz, 2H ), 1.55 (t, J = 6.8 Hz, 3H ); 13C NMR (100 MHz, CDCl3): δ = 188.8, 166.3, 165.6, 163.8, 163.1, 155.0, 148.9, 143.6, 143.2, 130.3, 130.2, 128.3, 128.2, 124.8, 121.3, 116.2, 115.9, 115.6, 115.5, 114.4, 114.0, 102.8, 102.5, 65.0, 15.0; MS (ESI): [M + H+], Calcd.
For: C25H19F2O3 (405.1258); Found: 405.1251.
(E)-2-(8-ethoxy-2-(4-methoxyphenyl)-4H-chromen-4-ylidene)-1-(4-methoxyphenyl)ethanone (10j):
Yellow solid, mp 184-187 °C; IR (KBr): 2924, 1690, 1636, 1601, 1541, 1511, 1259, 1167, 1072, 1024, 829 cm-1; 1H NMR (400 MHz, CDCl3): δ = 8.89 (s, 1H), 8.03-7.95 (m, 4H), 7.51 (d, J = 8.4 Hz, 1H), 7.18 (t, J = 8.0 Hz, 1H), 7.03-7.00 (m, 2H),6.96 (t, J = 8.0 Hz, 4H), 4.17 (q, J = 7.2 Hz, 2H), 3.86 (s, 6H), 1.54 (t, J = 6.8 Hz, 3H); 13C NMR (100 MHz, CDCl3): δ = 189.0, 162.5, 161.6, 155.5, 148.8, 143.6, 142.6, 134.5, 129.9, 127.8, 125.4, 124.4, 121.6, 114.4, 114.3, 113.8, 113.7, 102.3, 101.4, 64.9, 55.6, 15.0; MS (ESI): [M + H+] Calcd. For: C27H25O5 (429.1657); Found: 429.1645.
(E)-1-(4-chlorophenyl)-2-(2-(4-chlorophenyl)-8-methoxy-4H-chromen-4-ylidene)ethanone (10k):
Yellow solid, mp 262-264 °C; IR (KBr): 2923, 1690, 1639, 1571, 1538, 1245, 1221, 1072, 1012, 777 cm-1; 1H NMR (400 MHz, CDCl3): δ = 8.92 (s, 1H), 7.98-7.92 (m, 4H), 7.51 (d, J = 8.4 Hz, 1H), 7.44 (d, J = 8.0 Hz, 4H), 7.26-7.23(m, 1H),7.06 (d, J = 7.6 Hz, 1H), 7.02 (s, 1H), 3.99 (s, 3H); 13C NMR (100 MHz, CDCl3): δ = 189.0, 155.0, 149.6, 143.4, 143.1, 139.8, 138.1, 136.9, 131.2, 129.3, 129.2,
Part A: Chapter III
Experimental section
128.9, 127.5, 124.9, 121.3, 114.5, 112.9, 103.2, 103.1, 56.5; MS (ESI): [M + H+] Calcd. For:
C24H1735.5Cl2O3 (424.0447); Found: 424.0449.
(E)-2-(8-methoxy-2-(p-tolyl)-4H-chromen-4-ylidene)-1-(p-tolyl)ethanone (10l):
Yellow solid, mp 180-183 °C; IR (KBr): 2922, 1734, 1636, 1607, 1569, 1521, 1230, 1154, 1075, 1014, 784 cm-1; 1H NMR(400 MHz, CDCl3):
δ = 8.95 (s, 1H), 7.94 (d, J = 7.2 Hz, 4H), 7.55 (d, J = 8.0 Hz, 1H), 7.28 (d, J = 7.6 Hz, 5H), 7.08 (s, 1H), 7.05 (d, J = 7.6 Hz, 1H), 4.00 (s, 3H), 2.42 (s, 6H); 13C NMR (100 MHz, CDCl3): δ = 190.2, 155.9, 149.6, 143.6, 142.7, 142.2, 141.0, 139.0, 130.1, 129.7, 129.3, 127.9, 126.2, 124.5, 121.6, 114.6, 112.7, 103.1, 102.3, 56.5, 21.8, 21.7; MS (ESI): [M + H+] Calcd. For:
C26H23O3 (383.1602); Found: 383.1601.
(E)-2-(6-methoxy-2-phenyl-4H-chromen-4-ylidene)-1-phenylethanone (10m):
Yellow solid, mp 114-115 °C;IR (KBr): 2928, 1700, 1660, 1626, 1486, 1271, 1152, 1036, 794 cm-1; 1H NMR (400 MHz, CDCl3): δ
= 8.96 (s, 1H), 8.02 (brs, 2H), 7.48 (brs, 4H), 7.39 (brs, 3H), 7.33 (brs, 2H), 6.93 (t, J = 9.6 Hz, 1H), 6.74 (d, J = 7.2 Hz, 1H), 6.56 (s, 1H), 3.74 (s, 3H);13C NMR (150 MHz, CDCl3): δ = 196.3, 156.3, 152.9, 130.7, 128.9, 128.6, 127.8, 126.2, 125.5, 120.3, 119.9, 118.9, 117.6, 115.4, 114.1, 113.9, 105.6, 102.9, 102.5, 56.1; MS (ESI): [M + H+] Calcd. For:
C24H19O3 (355.1289); Found: 355.1289.
(E)-1-(4-bromophenyl)-2-(2-(4-bromophenyl)-6-methoxy-4H-chromen-4ylidene)ethanone (10n):
Yellow solid, mp 163-164 °C; IR (KBr): 2924, 1734, 1639, 1611, 1528, 1211, 1024, 1006, 794, cm-1; 1H NMR (400 MHz, CDCl3): δ = 8.93 (s, 1H), 7.88 (t, J = 7.2 Hz, 4H), 7.62 (brs, 3H), 7.39 (d, J = 9.6 Hz, 1H), 7.35 (s, 1H), 7.26 (brs, 1H), 7.18 (d, J = 9.2 Hz, 1H), 6.96 (s, 1H), 3.94 (s, 3H);13C NMR (100 MHz, CDCl3): δ = 189.2, 157.0, 155.3, 147.7, 143.1, 140.3, 132.2, 131.9, 131.6, 129.5, 127.6, 126.6, 125.3, 120.9, 120.0, 119.9, 105.6, 102.6, 102.5, 56.1;. MS (ESI): [M]+, Calcd. For: C24H1679Br2O3 (512.9520); Found:
512.9501.
Part A: Chapter III
Experimental section
(E)-2-(6-bromo-2-(4-chlorophenyl)-4H-chromen-4-ylidene)-1-(4-chlorophenyl)ethanone (10o):
Yellow solid, mp 248-250 °C; IR(KBr): 2922, 1734, 1644, 1545, 1007, 826 cm-1; 1H NMR(400 MHz, CDCl3): δ = 8.86 (s, 1H), 8.08 (s, 1H), 7.96 (d, J = 8.4 Hz, 2H), 7.90 (d, J = 8.4 Hz, 2H), 7.64 (d, J = 8.8 Hz, 1H), 7.46 (t, J = 7.2 Hz, 4H), 7.30 (d, J= 9.2 Hz, 1H), 6.99 (s, 1H); MS (ESI): [M]+, Calcd. For: C23H1379Br 35.5Cl2O2
(472.9527); Found: 472.9523.
(E)-2-(8-ethoxy-2-(4-methoxyphenyl)-4H-chromen-4-ylidene)-1-phenylethanone (10p):
Yellow solid, mp 131-133 °C; IR (KBr): 2925, 1729, 1635, 1533, 1227, 1067, 728 cm-1; 1H NMR (600 MHz, CDCl3): δ = 8.95 (s, 1H), 8.10- 8.02 (m, 4H), 7.49-7.43 (m, 4H), 7.22 (t, J = 8.4 Hz, 2H), 7.08 (d, J = 3.6 Hz, 2H), 7.06 (d, J = 7.8 Hz, 1H), 4.20 (q, J =7.2 Hz, 2H), 3.89 (s, 3H), 0.88 (t, J = 6.6 Hz, 3H); 13C NMR (100 MHz, CDCl3): δ = 189.3, 162.7, 155.5, 148.9, 143.8, 142.4, 134.4, 132.9, 130.6, 130.1, 128.9, 126.2, 124.6, 121.7, 114.6, 114.2, 113.8, 103.4, 102.9, 65.2, 55.7, 15.1;
MS (ESI): [M + H+] Calcd. For: C26H23O4 (399.1552); Found: 399.1542.
(E)-1-(4-methoxyphenyl)-2-(2-(p-tolyl)-4H-chromen-4-ylidene)ethanone (10q):
Yellow solid, mp 153-155 °C; IR(KBr): 2920, 1729, 1634, 1607, 1546, 1323, 1262, 1002, 752, cm-1; 1H NMR (400 MHz, CDCl3): δ = 8.88 (s, 1H), 8.02-7.95 (m, 3H), 7.87 (d, J = 8.0 Hz, 2H), 7.51 (t, J = 7.6 Hz, 1H), 7.38 (d, J = 8.0 Hz, 1H), 7.31-7.25 (m, 3H), 7.09 (s, 1H), 6.95 (d, J = 8.4 Hz, 2H), 3.86 (s, 3H), 2.39 (s, 3H); 13C NMR (100 MHz, CDCl3): δ = 189.0, 162.5, 155.9, 153.0, 142.1, 140.9, 134.3, 131.6, 129.9, 129.6, 127.9, 125.9, 124.9, 123.2, 120.7, 118.6, 113.7, 102.7, 102.4, 55.5, 21.6; MS (ESI): [M + H+] Calcd. For: C25H21O3 (369.1446); Found:
369.1431.
Complete crystallographic data of 10f for the structural analysis have been deposited with the Cambridge Crystallographic Data Centre, as supplementary publication with CCDC no.
1008522.
Part A: Chapter III
Experimental section
Table 7: Crystal data and structure refinement for 10f. For atomic coordinates and equivalent isotropic displacement parameters and bond angles, please check the CIF.
Parameters Compound 10f Parameters Compound 10f
Identification code sb-320 Z 4
Empirical formula C25H20O4 Density (calculated) 1.321g/cm3
Formula weight 384.41 Absorption
coefficient
0.089mm-1
Temperature 296 K F(000) 808.0
Wavelength 0.71073Å Theta range for data collection
1.45 to 25.24 º
Crystal system Orthorhombic Index ranges -6<=h<= 6, -15<=k<=14,
-31<=l<=33 Space group P2(1)2(1)2(1) Reflections
collected
23107
Unit cell dimensions Independent
reflections
3496 Rint = 0.0743
a 5.2558(8) Å Completeness to θº 99%(θ = 25.24 º) b 13.1158(16)Å Refinement method Full-matrix least-
squares on F2
c 28.043(4)Å Data / restraints /
parameters
3496 / 0 / 264
α 90.00º Goodness-of-fit on
F2
0.952
β 90.00º Final R indices
[>2sigma(I)]
Robs = 0.0498, wRobs = 0.1339 γ 90.00º R indices (all data) Rall = 0.0839, wRall
= 0.1568 Volume 1933.1(5)Å3 Largest diff. peak
and hole
0.145 and - 0.181e.Å-3
Part A: Chapter III
Experimental section
1H NMR (400 MHz, CDCl3): (E)-1-(thiophen-2-yl)-2-(2-(thiophen-2-yl)-4H-chromen-4-ylidene)ethanone(10g):
13C NMR (100MHz, CDCl3):(E)-1-(thiophen-2-yl)-2-(2-(thiophen-2-yl)-4H-chromen-4-ylidene)ethanone(10g):
Figure 14
Part A: Chapter III
Experimental section
1H NMR (600MHz, CDCl3):(E)-2-(8-ethoxy-2-phenyl-4H-chromen-4-ylidene)-1-phenylethanone(10h):
13C NMR (150MHz, CDCl3):(E)-2-(8-ethoxy-2-phenyl-4H-chromen-4-ylidene)-1-phenylethanone(10h):
Figure 15
Part A: Chapter III
Experimental section
1H NMR (400 MHz, CDCl3): (E)-1-(4-bromophenyl)-2-(2-(4-bromophenyl)-6-methoxy-4H-chromen-4 ylidene)ethanone (10n):
13C NMR (150MHz, CDCl3): (E)-1-(4-bromophenyl)-2-(2-(4-bromophenyl)-6-methoxy-4H-chromen-4 ylidene)ethanone (10n):
Figure 16
Part A: Chapter III
Experimental section
1H NMR (600 MHz, CDCl3):(E)-2-(8-ethoxy-2-(4-methoxyphenyl)-4H-chromen-4-ylidene)-1- phenylethanone(10p):
13C NMR (100MHz, CDCl3):(E)-2-(8-ethoxy-2-(4-methoxyphenyl)-4H-chromen-4-ylidene)-1- phenylethanone(10p):
Figure 17
Part A: Chapter III
Experimental section
1H NMR (400 MHz, CDCl3):(E)-1-(4-methoxyphenyl)-2-(2-(p-tolyl)-4H-chromen-4-ylidene)ethanone (10q):
13C NMR (100MHz, CDCl3):(E)-1-(4-methoxyphenyl)-2-(2-(p-tolyl)-4H-chromen-4-ylidene)ethanone (10q):
Figure 18