178
C. Selvarasu, P. Kannan / Journal of Molecular Structure 1092 (2015) 176–186
O
H
O
O
l
COC
H
COO
H
O
O
(1)
l
SOC 2
DM
SO
H
O
H
C12 25O
Benzene
aq NaOH
enzene
B
l
SOC 2
O
H25
OC12
H25
OC12
O
l
C
O
(2)
O
H
C12 25O
H
O
X
N
TEA THF
/
N
N
N
O
(3a-3e)
X
O
O
O
Where X = 4a = CN
=
4b Cl
H
C12 25O
c =
4
H
=
4d CH3
4e = OCH3
Scheme 1. Synthetic of liquid crystal compounds (4a–4e).
with agitation for 30 min. Afterwards 3-(4-((4-(dodecyloxy)ben-
zoyl)oxy)phenyl)acrylic acid chloride (2) (0.7 g, 3.1 mol) in 25 mL
of THF was added drop wise keeping the temperature in the range
0 to À5 °C. Temperature of the reaction mixture was allowed to
rise slowly to room temperature and the content was stirred for
1 h. The quaternary ammonium salt thus formed was filtered and
the solvent was evaporated in a rotary evaporator, the crude solid
obtained was washed with petroleum-ether and purified by col-
umn chromatography (Yield: 65%). The similar procedure was
adapted for the synthesis of other substituted compounds (4b–
4e; Scheme 1). C42H43N3O5: calcd C 75.31, H 6.47, N 6.27; found
C 75.20, H 6.39, N 6.23. FT-IR (KBr pellet, cmÀ1): 2854, 2934
(CAH stretch. aliphatic), 1730 (C@O, ester), 1623 (C@C stretch.
vinyl group of cinnamate), 1616 cmÀ1 (N@N), 1601 (C@C str. of
Aromatic), 1160 (CAO str. of ester), 950 (CAH plane bending). 1H
NMR (400 MHz, CHCl3) d 8.30–6.94 (d, aromatic-H, 16H), 7.48 (d,
J = 13.5 Hz, olefinic-H, 1H), 6.51 (d, J = 13.5 Hz, olefinic-H, 1H),
4.04–3.39 (t, J = 6.5 Hz, AOCH2, 2H), 1.54–1.23 (m, aliphatic-CH2,
20H), 0.93–0.90 (m, aliphatic CH3, 3H).13C NMR (125 MHz, CHCl3)
d: 13.9 (aliphatic-CH3), 21.8–31.4 (aliphatic-CH2), 68.3(OCH2),
113.6–154.2 (aromatic carbon), 115.9, 146.9 (olefinic carbon)
117.3 (aromatic-CN), 164.7 (AC@O ester).
stretch. aliphatic), 1726 (C@O, ester), 1610 (C@C stretch. vinyl
group of cinnamate), 1601 cmÀ1 (N@N), 1605 (C@C str. of aro-
matic), 1152 (CAO str. of ester), 953 (CAH plane bending). 1H
NMR (400 MHz, CHCl3) d 8.38–6.99 (d, aromatic-H, 17H), 7.50 (d,
J = 13.4 Hz, olefinic-H, 1H), 6.49 (d, J = 13.4 Hz, olefinic-H, 1H),
4.04–4.01 (t, J = 6.8 Hz, OCH2, 2H), 1.60–1.29 (m, aliphatic CH2,
20H), 0.80–0.72 (s, aliphatic CH3, 3H). 13C NMR (125 MHz, CHCl3)
d: 13.8 (aliphatic CH3), 21.5–30.6 (aliphatic-CH2), 67.8 (OCH2),
112.3–152.9 (aromatic carbon), 113.7, 147.7 (olefinic carbon),
163.3 (AC@O ester).
4-((E)-3-oxo-3-(4-((E)-p-tolyldiazenyl)phenoxy)prop-1-en-1-
yl)phenyl 4-(dodecyloxy)benzoate (4d)
C42H46N2O5: Yield: 59%. calcd C 76.56, H 7.03, N 4.25; found C
76.17, H 6.96, N 4.05. FT-IR (KBr pellet, cmÀ1): 2848, 2911 (CAH
stretch. aliphatic), 1733 (C@O, ester), 1621 (C@C stretch. vinyl
group of cinnamate), 1612 cmÀ1 (N@N), 1606 (C@C str. of aro-
matic), 1164 (CAO str. of ester), 925 (CAH plane bending).1H
NMR (125 MHz, CHCl3) d 8.40–6.99 (d, aromatic-H, 16H), 7.51 (d,
J = 13.4 Hz, olefinic-H, 1H), 6.53 (d, J = 13.4 Hz, olefinic-H, 1H),
4.08–4.03 (t, J = 6.4 Hz, OCH2, 2H), 2.45–2.38 (s, aromatic-CH3,
3H), 1.51–1.29 (m, aliphatic-CH2, 20H), 0.91–0.90 (s, aliphatic-
CH3, 3H).13C NMR (125 MHz, CHCl3) d: 13.0 (aliphatic-CH3), 20.4–
21.6 (aromatic-CH3) 25.0–30.9 (aliphatic-CH2), 67.3 (OCH2),
111.0–151.9 (s, aromatic carbon), 113.3, 149.2 (olefinic carbon),
163.9 (AC@O ester) (see Fig. 3).
4-((E)-3-(4-((E)-(4-chlorophenyl)diazenyl)phenoxy)-3-oxoprop-1-en-
1-yl)phenyl 4-(dodecyloxy)benzoate (4b)
C41H43N2O5: Yield: 60%. calcd C 72.60, H 6.39, N 4.13; found C
72.10, H 6.26, N 4.02. FT-IR (KBr pellet, cmÀ1): 2864, 2942 (CAH
stretch. aliphatic), 1723 (C@O, ester), 1618 (C@C stretch. vinyl
group of cinnamate), 1611 cmÀ1 (N@N), 1587 (C@C str. of aro-
matic), 1154 (CAO str. of ester), 955 (CAH plane bending). 1H
NMR (400 MHz, CHCl3) d 8.25–6.95 (d, aromatic-H, 16H), 7.49 (d,
J = 13.3 Hz, olefinic-H, 1H), 6.52 (d, J = 13.3 Hz, olefinic-H, 1H),
4.07–4.03 (t, J = 6.6 Hz, AOCH2, 2H), 1.64–1.26 (m, aliphatic CH2,
20H), 0.89–0.84 (s, aliphatic CH3, 3H).13C NMR (125 MHz, CHCl3)
d: 13.6 (aliphatic CH3), 21.4–31.4 (aliphatic-CH2), 67.7 (OCH2),
112.5–152.3 (aromatic carbon), 113.8, 147.5 (olefinic carbon),
163.5 (AC@O ester).
4-((E)-3-(4-((E)-(4-methoxyphenyl)diazenyl)phenoxy)-3-oxoprop-1-
en-1-yl)phenyl 4-(dodecyloxy)benzoate (4e)
C42H46N2O6: Yield: 75%. calcd C 74.75, H 6.87, N 4.15; found C
74.14, H 6.58, N 4.14. FT-IR (KBr pellet, cmÀ1): 2851, 2957 (CAH
stretch. aliphatic), 1724 (C@O, ester), 1617 (C@C stretch. vinyl
group of cinnamate), 1597 cmÀ1 (N@N), 1616 (C@C str. of
Aromatic), 1150 (CAO str. of ester), 951 (CAH plane bending). 1H
NMR (400 MHz, CHCl3) d 8.34–6.95 (d, aromatic-H, 16H), 7.48 (d,
J = 13.5 Hz, olefinic-H, 1H), 6.46 (d, J = 13.5 Hz, olefinic-H, 1H),
4.03–3.99 (t, J = 6.8 Hz, AOCH2, 2H), 3.87 (s, aroamtic-OCH3, 3H),
1.62–1.24 (m, aliphatic-CH2, 20H), 0.92–0.90 (s, aliphatic-CH3,
3H).13C NMR (125 MHz, CHCl3) d: 13.4 (aliphatic CH3), 21.8–30.3
(aliphatic CH2), 54.8 (aromatic-OCH3), 67.9 (OCH2), 112.3–152.3
(aromatic carbon), 113.6, 147.9, (olefinic carbon), 164.6 (AC@O
ester).
4-((E)-3-oxo-3-(4-((E)-phenyldiazenyl)phenoxy)prop-1-en-1-
yl)phenyl 4-(dodecyloxy)benzoate (4c)
C41H44N2O5: Yield: 71%. calcd C 76.37, H 6.87, N 4.34; found C
76.02, H 6.29, N 4.27. FT-IR (KBr pellet, cmÀ1): 2872, 2936 (CAH