Vìsnik Odesʹkogo Nacìonalʹnogo Unìversitetu: Hìmìâ (May 2018)

SYNTHESIS AND PROPERTIES OF TETRAOCTYLAMMONIUM SALTS OF 4,5-DISUBSTITUTED NAPHTHALIMIDES

  • N. F. Fed’ko,
  • M. V. Shevchenko,
  • І. S. Mokrukha,
  • V. V. Veduta

DOI
https://doi.org/10.18524/2304-0947.2018.2(66).132047
Journal volume & issue
Vol. 23, no. 2(66)
pp. 77 – 85

Abstract

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The tetraoctylammonium salts of 4,5-dichloro-1,8-naphthalimide, 4,5-dibromo-1,8-naphthalimide, 4,5-dinitro-1,8-naphthalimide and 4-bromo-5-nitro-1,8-naphthalimide were synthesized with high yields of 93-96 %. The synthesis was performed with corresponding 4,5-disubstituted 1,8-naphthalimides and tetraoctylammonium iodide as starting materials in two-phase system “benzene – 5% NaOH aqueous solution” at room temperature by anion exchange and subsequent extraction of the desired salts into organic phase. Starting 4,5-dichloro-, 4,5-dibromo-, 4,5-dinitro- and 4-bromo-5-nitro-1,8-naphthalimides were obtained by oxidation of 4,5-disubstituted acenaphthenes and further acylation of ammonia by corresponding 4,5-disubstituted naphthalic anhydrides. The structures of the synthesized tetraoctylammonium salts of 4,5-disubstituted 1,8-naphthalimides were confirmed by IR and NMR 1Н spectroscopy. It was observed that signals of aromatic protons of tetraoctylammonium salts are situated in NMR 1H spectra in stronger field in comparison with corresponding 4,5-disubstituted naphthalimides. Furthermore, the valence vibration band of NH bond is absent in IR spectra of obtained tetraoctylammonium salts, while the band of imide carbonyl group is shifted to the low frequency region comparing to corresponding 4,5-disubstituted naphthalimides. The obtained tetraoctylammonium salts of 4,5-disubstituted naphthalimides are soluble in nonpolar organic solvents, for example in benzene and toluene, unlike the corresponding naphthalimides. The ability of tetraoctylammonium salts of 4,5-disubstituted naphthalimides to be effective donors of 4,5-disubstituted 1,8-naphthalimide fragment in mild conditions was shown. The proposed method for the synthesis of functional derivatives of 4,5-disubstituted naphthalimides, based on the alkylation reactions of tetraalkylammonium salts, has a number of synthetic advantages in comparison with the method of acylation of primary amines with naphthalic anhydrides and the method of phase-transfer catalytic alkylation of naphthalimides.

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