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Aim. To synthesize 4-fluoro-1,8-naphthalic acid imide and its derivatives substituted in the imide ring. Results and discussion. 4-Fluoro-1,8-naphthalimide was obtained using acenaphthene as the starting material. N-alkyl-4-fluoro-1,8-naphthalimides were synthesized via the phase transfer catalytic alkylation of 4-fluoro-1,8-naphthalimide with haloalkanes. Imidation of 4-fluoro-1,8-naphthalic anhydride with aminoacids resulted in the formation of N-carboxyalkyl-1,8-naphthalimides. These substances can be considered as potential fluorescent labels capable of binding to amino groups of various biological molecules as they contain carboxylic functionality in their structure. Experimental part. The structure of the compounds synthesized was confirmed by FT-IR, 1H NMR and 13C NMR spectroscopy, and mass-spectrometry. Conclusions. It has been shown that 4-fluoro-1,8-naphthalinedicarboxylic acid imide can be obtained following the synthetic route “acenaphthene – 5-fluoroacenaphthene – 4-fluoro-1,8-naphthalic anhydride – 4-fluoro-1,8-naphthalimide”. 4-Fluoro-1,8-naphthalimide can be alkylated by butyl iodide and octyl bromide using tetraalkylammonium salts as a phase transfer catalyst resulted in N-butyl-4-fluoro-1,8-naphthalimide and N-octyl-4-fluoro-1,8-naphthalimide. As a result, N-carboxyalkyl-4-fluoro-1,8-naphthalimides have been obtained for the first time by aminolysis of 4-fluoro-1,8-naphthalic anhydride with glycine, β-alanine and 6-aminocaproic acid.

[Display omitted] • A novel photochromic system – hetarylalkylidenisochromandiones - was synthesized. • Furanyl derivatives in crystalline form are capable of reversible photocyclization. • Yellow crystals turn dark blue-green upon irradiation with light of 436 nm. • In solutions, they undergo photorearrangement into highly fluorescent naphthalic anhydrides. A novel photochromic system based on an alkylideneisochromanedione core with heterocyclic substituents was synthesized, and its spectral luminescent and photoinduced properties were studied. The obtained isochromandiones containing the hexatriene fragment exist in a ring-open E -form, confirmed by the data of 1H, 13C NMR spectroscopy and X-ray diffraction studies. The observed photoinitiated processes depend fundamentally on the nature of the heterocyclic substituents. Thiophenyl, benzo[ b ]thiophenyl and 1 H -indolyl derivatives 5c-f are non-photochromic in the solid state, and in solutions their transformations are limited by thermally reversible E/Z -photoisomerization. Compound 5a with a furanyl substituent is photochromic in crystalline form due to the light-induced rearrangement of the ring-open hexatriene isomer into the ring-closed cyclohexadiene structure. Upon irradiation with light of 436 nm, the yellow crystals of 5a turn dark blue-green. The reverse reaction of the cycle opening and restoration of the original color of the crystals occurs extremely easily upon irradiation with visible light of 578 nm. In contrast to crystals, solutions of compounds 5a and 5b with furanyl substituents in hexane, 2-propanol, acetonitrile and DMSO are discolored when irradiated with light of 365 nm. The irreversible photorearrangement 5a,b → 6a,b includes the stages of cyclization, the opening of the furan cycle and the formation of highly fluorescent naphthalic anhydride derivatives 6 (the quantum yield of fluorescence reaches 0.69 in hexane)), which can be used for the production of optical memory media for archive 3D discs. [ABSTRACT FROM AUTHOR]