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Synthesis of 4,6-bis(thiomorpholin-4-ylmethyl)-1,2,3-benzenetriol

Molbank 2009, 2009(1), M598; https://doi.org/10.3390/M598

Short Note
Synthesis of New Schiff Base Ether: p-n-(Dimethylamino)-benzylidene-p-dodecyloxyaniline
1
Faculty of Engineering & Science, Universiti Tunku Abdul Rahman, Jln Genting Kelang, Setapak, 53300 Kuala Lumpur, Malaysia
2
Present address: Department of Chemistry, University of York, Heslington, York, YO10 5DD, United Kingdom
*
Author to whom correspondence should be addressed.
Received: 25 November 2008 / Accepted: 24 March 2009 / Published: 24 March 2009

Abstract

:
A new Schiff base ether, p-n-(dimethylamino)benzylidene-p-dodecyloxyaniline, was synthesized and its IR, 1H NMR, 13C NMR and MS spectroscopic data are reported.
Keywords:
p-n-(dimethylamino)benzylidene-p-dodecyloxyaniline; Schiff base; alkyl chain
Compounds containing two aromatic rings with terminal substituents or multiple substituents are low-mass molecules capable of exhibiting liquid crystal properties [1]. Typical examples include Schiff base esters consisting of an ester linkage at one end and different substituents residing at the other end along the long molecular axis. As a continuation of our previous investigations [2,3,4,5,6,7,8,9], in this paper we report a new Schiff base ether with a potential to exhibit mesomorphic properties. Due to the presence of the dimethylamino group, this molecule may also serve as a mesogenic charge-transfer donor [10].
Molbank 2009 m598 i001
A solution of 4-dimethylaminobenzaldehyde (1.19 g, 8 mmol) and 4-aminophenol (0.87 g, 8 mmol) in absolute ethanol (40 mL) was heated under reflux for 3 hours. Compound 1 thus obtained was recrystallized from absolute ethanol. Then, Schiff base 1 (0.48 g, 2.0 mmol) in acetone (40 ml), was added to a solution of potassium hydroxide (0.11 g, 2.0 mmol) in distilled water (10 ml). This was followed by addition of a small amount of potassium iodide into the mixture. The reaction mixture was heated under reflux for an hour upon stirring. 1-Bromododecane (0.75 g, 3.0 mmol) was then added to the flask and reflux was continued for 24 hours. The yellow product obtained was repeatedly recrystallized with absolute ethanol whereupon the pure compound was isolated as a yellow solid (0.43 g, 53%).
Melting Point: 94.5oC.
EI-MS m/z (rel. int. %): 409 (30) [M+1]+, 408(100) [M]+, 240 (40), 239 (95).
IR νmax (KBr) cm-1: 2850–2950 (C–H aliphatic); 1611 (C=N); 1592, 1502 (C=C aromatic).
1H NMR (300 MHz, CDCl3): δ/ppm 0.90 (t, 3H, J = 6.7 Hz, CH3), 1.29-1.48 (m, 18H, CH3-(CH2)9-CH2-CH2-O-), 1.80 (qt, 2H, J = 7.4 Hz, -CH2-CH2-O-), 3.07 {s, 6H, 2 x N(CH3)2}, 3.98 (t, 2H, J = 6.6 Hz, -CH2-O-), 6.74 (d, 2H, J = 8.8 Hz, Ar-H), 6.91 (d, 2H, J = 8.7 Hz, Ar-H), 7.19 (d, 2H, J = 8.7 Hz, Ar-H), 7.76 (d, 2H, J = 8.7 Hz, Ar-H), 8.37 (s, 1H, CH=N).
13C NMR (75 MHz, CDCl3): δ/ppm 14.63 (CH3), 23.17, 26.51, 29.78, 29.83, 29.89, 30.06, 30.08, 30.11, 30.14, 32.38 for methylene carbons {-(CH2)10CH2O-}, 40.65 {N(CH3)2}, 68.63 (–CH2O–), 111.98, 115.25, 122.40, 124.97, 130.59, 146.08, 152.64, 157.48 for aromatic carbons, 159.04 (CH=N).
Elemental analysis: Calculated for C27H40N2O: C, 79.36%, H, 9.87%, N, 6.86%; Found: C, 79.40%, H, 9.75%, N, 6.79%.

Supplementary materials

Supplementary File 1Supplementary File 2Supplementary File 3

Acknowledgements

The author (S.T. Ha) would like to thank Universiti Tunku Abdul Rahman (UTAR) for the research facilities and the financial support through UTAR Vote No. 6202/O05. L.K. Ong would like to acknowledge UTAR for the award of the research assistantship.

References and Notes

  1. Jacobi, A.; Weissflog, W. Liq. Cryst. 1997, 22, 107. [CrossRef]
  2. Yeap, G.Y.; Ha, S.T.; Lim, P.L.; Boey, P.L.; Mahmood, W.A.K.; Ito, M.M.; Sanehisa, S. Mol. Cryst. Liq. Cryst. 2004, 423, 73–84.
  3. Yeap, G.Y.; Ha, S.T.; Lim, P.L.; Boey, P.L.; Ito, M.M.; Sanehisa, S.; Vill, V. Mol. Cryst. Liq. Cryst. 2006, 452, 63–72. [CrossRef]
  4. Yeap, G.Y.; Ha, S.T.; Boey, P.L.; Mahmood, W.A.K.; Ito, M.M.; Youhei, Y. Mol. Cryst. Liq. Cryst. 2006, 452, 73–90. [CrossRef]
  5. Yeap, G.Y.; Ha, S.T.; Lim, P.L.; Boey, P.L.; Ito, M.M.; Sanehisa, S.; Youhei, Y. Liq. Cryst. 2006, 33, 205–211. [CrossRef]
  6. Ha, S.T.; Ong, L.K.; Win, Y.F.; Koh, T.M.; Yeap, G.Y. Molbank 2008, 3, M582. [CrossRef]
  7. Ha, S.T.; Ong, L.K.; Win, Y.F.; Koh, T.M.; Yeap, G.Y. Molbank 2009, 1, M584.
  8. Ha, S.T.; Ong, L.K.; Win, Y.F.; Koh, T.M.; Yeap, G.Y. Molbank 2009, 1, M585.
  9. Ha, S.T.; Ong, L.K.; Win, Y.F.; Koh, T.M.; Yeap, G.Y. Molbank 2009, 1, M591.
  10. Narasimhaswamy, T.; Srinivasan, K.S.V. Liq. Cryst. 2004, 31, 1457–1462. [CrossRef]
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