M. Fathimunnisa et al. / Journal of Molecular Structure 1099 (2015) 407e418
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2.6. General procedure for the synthesis of (2E)-1-[4-(2,4-
2.6.5. (2E)-1-[4-(2,4-difluorophenyl)phenyl]3-(2-methoxyphenyl)
difluorophenyl)phenyl]3-arylprop-2-en-1-ones (7e14)
prop-2-en-1-one (11)
Pale yellow solid; Yield 97%; mp. 118e120 ꢁC; IR (KBr, cmꢀ1):
1663 (C]O), 3094-3029 (aromatic CeH), 2938-2835 (aliphatic
Equimolar mixture of 1-(20,40-difluorobiphenyl-4-yl)ethanone
(1 mmol) and aryl aldehydes (1 mmol) was dissolved in ethanol
(20 ml). The sodium hydroxide in water (10%, 2 ml) was added
dropwise to the mixture under constant stirring using magnetic
stirrer. The reaction mixture was immersed in the crushed ice to
maintain the temperature at about 20 ꢁC. The reaction mixture was
stirred vigorously for about 1e2 h until the mixture become thick
and the stirring is no longer effective. The reaction mixture was
neutralized with dil. HCl and kept in the refrigerator overnight. The
product was filtered under vacuum, washed with water, dried and
recrystallized from ethanol.
CeH), 1596 (C]C), 1108, 1143 (CeF); 1H NMR (400 MHz, CDCl3,
d,
ppm): 7.48 (d, 1H, H(2), J ¼ 12 Hz), 8.16 (d, 1H, H(3), J ¼ 16 Hz), 8.10
(d, 2H, H(200) and H(600)), 6.98 (m, 2H, H(30) and H(50)), 7.38e7.69
(m, 7H, AreH), 3.94 (s, 3H, OCH3); 13C (100 MHz, CDCl3,
d, ppm):
190.5 (C]O), 120.8C(2), 140.6C(3), 104.6C(30), 111.9C(50), 159.9C(40),
162.8C(20), 111.3e158.9 (AreC), 55.6 (OCH3); mass (m/e): 351.0
[Mþ1]þ; Anal. Calcd (C22H16F2O2): C 75.42H 4.60%. Found: C 74.25H
4.62%.
2.6.6. (2E)-1-[4-(2,4-difluorophenyl)phenyl]3-(thiophenyl)prop-2-
en-1-one (12)
2.6.1. (2E)-1-[4-(2,4-difluorophenyl)phenyl]3-phenylprop-2-en-1-
one (7)
Pale yellow solid; Yield 92%; mp. 120e122 ꢁC; IR (KBr, cmꢀ1):
1654 (C]O), 3108-3039 (aromatic CeH), 2922-2851 (aliphatic
Yellow solid; Yield 95%; mp. 102e104 ꢁC; IR (KBr, cmꢀ1): 1666
(C]O), 3094-3021 (aromatic CeH), 2924-2855 (aliphatic CeH),
CeH), 1588 (C]C), 1099, 1137 (CeF); 1H NMR (400 MHz, CDCl3,
d,
ppm): 7.49 (d, 1H, H(2), J ¼ 12 Hz), 7.99 (d, 1H, H(3), J ¼ 16 Hz), 8.09
1597 (C]C), 1098, 1141 (CeF); 1H NMR (400 MHz, CDCl3,
d, ppm):
(d, 2H, H(200) and H(600)), 6.98 (m, 2H, H(30) and H(50)), 7.11e7.65 (m,
7.57 (d, 1H, H(2), J ¼ 16 Hz), 7.85 (d, 1H, H(3), J ¼ 16 Hz), 8.10 (d, 2H,
6H, AreH); 13C (100 MHz, CDCl3,
d, ppm): 189.3 (C]O), 120.6C(2),
H(200) and H(600)), 6.97 (m, 2H, H(30) and H(50)), 7.43e7.66 (m, 8H,
140.4C(3), 104.7C(30), 111.9C(50), 159.9C(40), 162.8C(20), 124.3e139.4
(AreC); mass (m/z): 327.1 [Mþ1]þ; Anal. Calcd (C19H12F2OS): C
69.92H 3.71 S 9.83%. Found: C 67.16H 3.68 S 9.28%.
AreH); 13C (100 MHz, CDCl3,
d
, ppm): 189.9 (C]O), 121.9C(2),
145.1C(3), 104.7C(30), 111.9C(50), 159.9C(40), 162.8C(20), 124.2e139.4
(AreC); 19F (376 MHz, CDCl3,
d,
ppm): ꢀ112.86 (d, 1F,
J ¼ 7.52 Hz), ꢀ109.84 (d, 1F, J ¼ 7.52 Hz); mass (m/z): 321.1 [Mþ1]þ;
2.6.7. (2E)-1-[4-(2,4-difluorophenyl)phenyl]3-(napthyl)prop-2-en-
1-one (13)
Anal. Calcd (C21H14F2O): C 78.74H 4.41%. Found: C 78.68H 4.53%.
Yellow solid; Yield 56%; m.p. 104e106 ꢁC; IR (KBr, cmꢀ1): 1654
(C]O), 3045-3007 (aromatic CeH), 2922-2849 (aliphatic CeH),
2.6.2. (2E)-1-[4-(2,4-difluorophenyl)phenyl]3-(4-methylphenyl)
prop-2-en-1-one (8)
1592 (C]C), 1098, 1143 (CeF); 1H NMR (400 MHz, CDCl3,
d, ppm):
Yellow solid; Yield 84%; mp. 138e140 ꢁC; IR (KBr, cmꢀ1): 1657
(C]O), 3074-3031 (aromatic CeH), 2914-2851 (aliphatic CeH),
7.60 (d, 1H, H(2), J ¼ 16 Hz), 8.72 (d, 1H, H(3), J ¼ 16 Hz), 8.17 (d, 2H,
H(200) and H(600)), 6.97 (m, 2H, H(30) and H(50)), 7.47e8.29 (m, 10H,
1596 (C]C), 1100, 1140 (CeF); 1H NMR (400 MHz, CDCl3,
d
, ppm):
AreH); 13C (100 MHz, CDCl3,
d, ppm): 189.7 (C]O), 124.9C(2),
7.54 (d, 1H, H(2), J ¼ 20 Hz), 7.84 (d, 1H, H(3), J ¼ 16 Hz), 8.09 (d, 2H,
141.9C(3), 104.7C(30), 111.9C(50), 159.9C(40), 162.8C(20), 123.5e139.5
(AreC); mass (m/z): 371.1 [M þ 1]þ; Anal. Calcd (C25H16F2O): C
81.07H 4.35%. Found: C 78.57H 4.33%.
H(200) and H(600)), 6.98 (m, 2H, H(30) and H(50)), 7.43e7.66 (m, 7H,
AreH), 2.41 (s, 3H, eCH3); 13C (100 MHz, CDCl3,
d, ppm): 190.1 (C]
O), 120.9C(2), 145.2C(3), 104.7C(30), 111.9C(50), 159.9C(40),
162.8C(20), 124.3e141.3 (AreC), 21.6 (CH3); mass (m/z): 335.0
[Mþ1]þ; Anal. Calcd (C22H16F2O): C 79.03H 4.82%. Found: C 77.94H
4.94%.
2.6.8. (2E)-1-[4-(2,4-difluorophenyl)phenyl]3-(cinnamyl)prop-2-
en-1-one (14)
Pale yellow solid; Yield 84%; m.p. 124e126 ꢁC; IR (KBr, cmꢀ1):
1650 (C]O), 3080-3024 (aromatic CeH), 2922-2857 (aliphatic
2.6.3. (2E)-1-[4-(2,4-difluorophenyl)phenyl]3-(4-fluorophenyl)
prop-2-en-1-one (9)
CeH), 1579 (C]C), 1099, 1140 (CeF); 1H NMR (400 MHz, CDCl3,
d,
ppm): 7.14 (d, 1H, H(2), J ¼ 16 Hz), 7.66 (d, 1H, H(3), J ¼ 12 Hz), 8.06
Pale yellow solid; Yield 89%; mp. 142e144 ꢁC; IR (KBr, cmꢀ1):
1664 (C]O), 3084-3041 (aromatic CeH), 2954-2853 (aliphatic
(d, 2H, H(200) and H(600)), 6.97 (m, 2H, H(30) and H(50)), 7.05e7.67 (m,
10H, AreH); 13C (100 MHz, CDCl3,
d, ppm): 189.9 (C]O), 125.3C(2),
CeH), 1600 (C]C), 1096, 1143 (CeF); 1H NMR (400 MHz, CDCl3,
d
,
145.1C(3), 104.7C(30), 111.9C(50), 159.9C(40), 162.8C(20), 125.3e142.2
(AreC); Anal. Calcd (C23H16F2O): C 79.75H 4.66%. Found: C 79.52H
4.84%.
ppm): 7.50 (d, 1H, H(2), J ¼ 16 Hz), 7.82 (d, 1H, H(3), J ¼ 16 Hz), 8.10
(d, 2H, H(200) and H(600)), 6.98 (m, 2H, H(30) and H(50)), 7.11e7.66 (m,
7H, AreH); 13C (100 MHz, CDCl3,
d, ppm): 189.7 (C]O), 121.6C(2),
143.7C(3), 104.7C(30), 111.9C(50), 159.9C(40), 162.8C(20), 116.1e165.4
(AreC); Anal. Calcd (C21H13F3O): C 74.55H 3.87%. Found: C 73.63H
3.98%.
3. Results and discussion
The schematic representation of synthesizing the biphenyl
based difluorochalcones starting from 20,40e difluorobiphenyl has
been described in Scheme 1. The 20,40e difluorobiphenyl has been
made to undergo FriedaleCrafts acylation reaction with ace-
toylchoride in the presence of dichloromethane and aluminium
chloride to synthesize 1-(20,40-difluorobiphenyl-4-yl)ethanone (6)
also reported in Ref. [25]. A series of (2E)-1-[4-(2,4-difluorophenyl)
phenyl]3-arylprop-2-en-1-ones (7e14) have been synthesized by
the Claisen-Schimidt condensation method with excellent yield. All
the synthesized compounds (7e14) have been characterized by
elemental analysis, FT-IR, 1H and 13C NMR and Mass spectroscopy.
The mass spectra of the compounds exhibit [Mþ1]þ peaks
which confirms the formation of product. The numbering of the
carbon atoms was displayed in Scheme 1 and the protons are
2.6.4. (2E)-1-[4-(2,4-difluorophenyl)phenyl]3-(3-methoxyphenyl)
prop-2-en-1-one (10)
Pale yellow solid; Yield 98%; mp. 122e124 ꢁC; IR (KBr, cmꢀ1):
1656 (C]O), 3062-3013 (aromatic CeH), 2934-2834 (aliphatic
CeH), 1595 (C]C), 1100, 1142 (CeF); 1H NMR (400 MHz, CDCl3,
d,
ppm): 7.54 (d, 1H, H(2), J ¼ 16 Hz), 7.81 (d, 1H, H(3), J ¼ 16 Hz), 8.10
(d, 2H, H(200) and H(600)), 6.98 (m, 2H, H(30) and H(50)), 7.17e7.66 (m,
7H, AreH), 3.87 (s, 3H, OCH3); 13C (100 MHz, CDCl3,
d, ppm): 189.9
(C]O), 121.2C(2), 144.9C(3), 104.7C(30), 111.9C(50), 159.9C(40),
162.8C(20), 113.5e159.9 (AreC), 55.4 (OCH3); mass (m/z): 351.0
[Mþ1]þ; Anal. Calcd (C22H16F2O2): C 75.42H 4.60%. Found: C 74.54H
4.64%.