A new method was developed for the synthesis of ethyl 3,6-diamino-4-aryl-5-cyanothieno[2,3-b]pyridine-2-carboxylates by the reaction of 4-aryl-2-amino-6-chloropyridine-3,5-dicarbonitriles with ethyl 2-mercaptoacetate. The synthesized compounds exhibit fluorescence both in solution and in the solid state. The emission maxima in benzene solution depend on the substituent and are in the range of 503–531 nm or from 498 to 541 nm in the solid state. For photoluminescence of ethyl 3,6-diamino-4-aryl-5-cyanothieno[2,3-b]pyridine-2-carboxylates, large Stokes shifts were observed: from 214 nm (13106 cm–1) in chloroform to 251 nm (14433 cm–1) in methanol.

A procedure has been developed for the synthesis of polyfunctionalized pyridine derivatives, 6′-amino-4′-aryl-3′,5′-dicyano[1,2′-bipyridin]-1-ium chlorides from simple precursors, malononitrile and aromatic aldehydes.

The reaction of 4-amino-6-aryl-2-halopyridine-3,5-dicarbonitriles with thioglycolic acid ethyl ester was used to synthesize a series of new efficient fluorophores of thieno[2,3- b ]pyridine series. The long-wavelength absorption bands of DMSO solutions of the prepared compounds are at the boundary of the UV and visible regions of the spectrum (λabs 375-388 nm) and show an ambiguous influence of the substituent electronic effect, that was explained by quantum chemical calculations. The emission maxima are in the yellow-green region (λem 490- 510 nm) and they are blue-shifted in the presence of electron donor groups with slightly increasing intensity (Φem 37.8-60.6%). It was found that the nitro group presence causes a complete photoluminescence quenching both in solution and in the solid state. In addition, the position of the emission maximum (λem 473-505 nm) and its intensity (Φem 3.6-72.7%) strongly depend on the polarity and the basic properties of the medium, that was established using the Catalan empirical model.

A method for the preparation of 2-morpholinocinchomeronic acid dinitrile derivatives (2-morpholinopyridine-3,4-dicarbonitriles) was developed. The optical properties of the obtained products were investigated both in solution and the solid state. It was found that the synthesized compounds exhibit fluorescence both in solution and in the solid state from the blue to green region of the spectrum, depending on the substituents at the fifth and sixth positions of the pyridine ring. It was found that the relative quantum yield in benzene reaches 50%.

Potassium salts of benzylidene and cinnamylidene derivatives of malononitrile trimer were obtained by reactions of substituted benzaldehydes and cinnamaldehydes with malononitrile trimer in aqueous medium under ultrasonic irradiation. The synthesized salts showed solid state fluorescence with the emission maxima located in the region λ 528–740 nm, depending on the substituent in the aromatic ring.

The reaction of 2-chloropyridine-3,4-dicarbonitrile with anilines in propan-2-ol in the presence of N,N- diisopropylethylamine (DIPEA) in a sealed vial at 120°С involves the nucleophilic substitution of chlorine and yields 2-(arylamino)pyridin-3,4-dicarbonitriles.

4-Amino-6-aryl-2-sulfanylpyridine-3,5-dicarbonitriles were obtained in two ways: by nucleophilic substitution of the halogen atom in 2-halopyridines under the action of thiols and by alkylation of pyridine-2-thiones with alkyl halides.

2,4-Diamino-6-arylpyridine-3,5-dicarbonitriles were synthesized by the nucleophilic substitution of bromine in 4-amino-2-bromo-6-arylpyridine-3,5-dicarbonitriles. The optical properties of the synthesized compounds were studied to show that they fluoresce in solution and in the solid state in the violet region of the spectrum.