Abstract
A new Schiff base ester 3-hydroxy-4-[(phenylimino)methyl]phenyl myristate was synthesized and its IR, 1H NMR, 13C NMR and MS spectroscopic data are presented.
Schiff bases have received a considerable amount of attention from many researchers owing to their importance in exhibiting thermochromism and photochromism [,,,]. Aromatic Schiff bases possessing long alkyl chain have received much attention due to their possibility to exhibit liquid crystalline properties such as smectic and nematic phases [,,,,].
Synthesis
4-Formyl-3-hydroxyphenyl tetradecanoate was previously prepared via Steglich esterification []. In a round-bottom flask, a mixture of the 4-formyl-3-hydroxyphenyl tetradecanoate (1.74 g, 5.0 mmol), aniline (0.47 g, 5.0 mmol) and absolute ethanol (50 mL) was refluxed with stirring for three hours. The reaction mixture was filtered and the solvent removed from the filtrate by evaporation. Recrystallization from absolute ethanol gave the title compound as yellow solid (1.14 g, 54%).
Melting point: 103.4 oC.
MS(EI): M+ (m/z) = 423 (4) [M]+, 213 (100).
IR (KBr, cm-1): 3435 (O-H), 2952, 2917, 2848 (C-H aliphatic); 1754 (C=O ester); 1629 (C=N); 1594, 1499 (C=C aromatic).
1H NMR (400 MHz, CDCl3): δ/ppm 0.90 (t, 3H, J = 6.9 Hz, CH3), 1.30-1.46 {m, 20H, CH3(CH2)10-}, 1.75 (q, 2H, J = 7.5 Hz, -CH2CH2COO-), 2.57 (t, 2H, J = 7.5 Hz, -CH2COO-), 6.71 (dd, 1H, J = 2.2, 8.4 Hz, Ar-H), 6.79 (d, 1H, J = 2.2 Hz, Ar-H), 7.28 (m, 3H, Ar-H), 7.39 (d, 1H, J = 8.4 Hz, Ar-H), 7.42 (m, 2H, Ar-H), 8.62 (s, 1H, CH=N), 13.60 (s, 1H, OH).
13C NMR (100 MHz, CDCl3): δ/ppm 172.1 (COO), 162.2 (CH=N), 163.0, 154.9, 148.6, 133.5, 129.8, 127.4, 121.6, 117.5, 113.3, 110.9 (aromatic carbons), 34.86 (-CH2COO-), 25.30 (-CH2CH2COO-), 32.34, 30.10, 30.07, 30.02, 29.88, 29.78, 29.67, 29.50, 23.11 (CH3(CH2)14-), 14.54 (CH3).
Elemental analysis: Calculated for C27H37NO3 C, 76.56%, H, 8.80%, N, 3.31%; Found: C, 76.45%, H, 8.87%, N, 3.44%.
Supplementary materials
Supplementary File 1Supplementary File 2Supplementary File 3Acknowledgements
The main author (S.T. Ha) would like to thank Universiti Tunku Abdul Rahman for the financial support and research facilities.
References and Notes
- Hadjoudis, E.; Vittorakis, M.; Moustakali-Mavridis, I. Photochromism and thermochromism of schiff bases in the solid state and in rigid glasses. Tetrahedron 1987, 43, 1345–1360. [Google Scholar]
- Hadjoudis, E.; Rontoyianni, A.; Ambroziak, K.; Dziembowska, T.; Mavridis, I.M. Photochromism and thermochromism of solid trans-N,N'-bis(salicylidene)-1,2-cyclohexanediamines and trans-N,N'-bis-(2-hydroxynaphylidene)-1,2-cyclohexanediamine. J. Photochem. Photobiol. A: Chem. 2004, 162, 521–530. [Google Scholar] [CrossRef]
- Oshima, A.; Momotake, A.; Arai, T. Photochromism, thermochromism, and solvatochromism of naphthalene-based analogues of salicylideneaniline in solution. J. Photochem. Photobiol. A: Chem. 2004, 162, 473–479. [Google Scholar]
- Yeap, G.Y.; Ha, S.T.; Ishizawa, N.; Suda, K.; Boey, P.L.; Mahmood, W.A.K. Synthesis, crystal structure and spectroscopic study of para substituted 2-hydroxy-3-methoxybenzalideneanilines. J. Mol. Struct. 2003, 658, 87–99. [Google Scholar] [CrossRef]
- Ha, S.T.; Ong, L.K.; Wong, J.P.W.; Yeap, G.Y.; Lin, H.C.; Ong, S.T.; Koh, T.M. Mesogenic Schiff's base ether with dimethylamino end group. Phase Transitions 2009, 82, 387–397. [Google Scholar] [CrossRef]
- Ha, S.T.; Ong, L.K.; Ong, S.T.; Yeap, G.Y.; Wong, J.P.W.; Koh, T.M.; Lin, H.C. Synthesis and mesomorphic properties of new Schiff base esters with different alkyl chains. Chin. Chem. Lett. 2009, 20, 767–770. [Google Scholar] [CrossRef]
- Ha, S.T.; Koh, T.M.; Ong, S.T.; Beh, J.K.; Ong, L.K. Synthesis of a new liquid crystal, 3-hydroxy-4-{[(6-methoxy-1,3-benzothiazol-2-yl)imino]methyl}phenyl palmitate. Molbank 2009, 2009, M608. [Google Scholar] [CrossRef]
- Ha, S.T.; Ong, L.K.; Win, Y.F.; Koh, T.M. 4-[(Pyridin-3-ylmethylene)amino]phenyltetradecanoate. Molbank 2009, 2009, M585. [Google Scholar] [CrossRef]
- Ha, S.T.; Ong, L.K.; Win, Y.F.; Koh, T.M. 4-[(Pyridin-3-ylmethylene)amino]phenylhexadecanoate. Molbank 2009, 2009, M584. [Google Scholar] [CrossRef]
- Ha, S.T.; Ong, S.T.; Chong, Y.T.; Yeap, G.Y. 4-{[(3-Chlorophenyl)imino]methyl}-3-hydroxyphenyl myristate. Molbank 2009, 2009, M629. [Google Scholar] [CrossRef]
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