Separate reaction of benzimidazolyl-2-guanidine and benzothiazolyl-2-guanidines with trichloroacetonitrile was investigated. 2,4-Diamino[1,3,5]triazino[1,2-a]benzimidazole and 2,4-diimino[1,3,5]triazino[2,1-a][1,3]benzothiazoles were found to be products of the reaction. The structures of the compounds obtained were established using ¹H NMR spectroscopy.

Medium-sized N-heterocycles, in particular eight-membered azocines, are key structures occurring in many natural products and in some compounds having biological activities. We described here an easy access to benzo[f][1,4]oxazocin-1-ones starting from 2-acetylbenzoic acid.

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Oxidative hydroxylation of pyrido[3,2,1-jk]carbazol-6-ones by hydrogen peroxide, peroxy carboxylic acids or nitric acid leads to 5-hydroxypyrido[3,2,1-jk]carbazole-4,6-diones, which give in alkaline solution ring contraction to oxindoles, dioxindoles and ring opening reactions to carbazolyl-hydroxyphenylpropanones depending on the reaction conditions and substituents at position 5. Wittig olefination of 5-hydroxypyrido[3,2,1-jk]carbazole-4,6-diones gives [2-(3-alkyl-3-hydroxy-2-oxo-1,2,3,4-tetrahydro-quinolinylidene)]-acetates.

2-Amino substituted 6,7-dimethoxy-4-trifluoromethyl-quinolines were synthesized from the 2-oxo derivatives by chlorination with phosphoryl chloride and aminated with 4-aminobenzoate to give a highly fluorescent molecule suitable for linking to appropriate biomolecules and biopolymers. The linking was achieved by conversion of the benzoate to reactive O-succinimide esters, which react easily with amino groups of biomolecules such as amino acids, aminosugars and the related biopolymers. The investigation of the fluorescent properties show pH independent properties and large Stokes shifts, however a rather low quantum yield.

The series of thirteen mono-substituted 3-arylaminopyrazine-2,5-dicarbonitriles was prepared by the reaction of 3-chloropyrazine-2,5-dicarbonitrile with the appropriated anilines. The general synthetic approach of all newly synthesized compounds is presented. All the substituted 3-arylaminopyrazine-2,5-dicarbonitriles, which showed significant antifungal and antimycobacterial activity, were analyzed using the reversed phase high performance liquid chromatography (RP-HPLC) method for the lipophilicity measurement. The procedure was performed under isocratic conditions with methanol as an organic modifier in the mobile phase using end-capped non-polar C₁₈ stationary RP column. In the present study the correlation between RP-HPLC retention parameter log K (the logarithm of capacity factor K) and log P data calculated in various ways is shown. The relationships between the lipophilicity and the chemical structure of the studied compounds are discussed as well.

A novel Zn(II) phthalocyanine derivative bearing four antifungal structure of fluconazole (ZnPcF) was synthesized by a two-step procedure starting from 4-nitrophthalonitrile. First, phthalonitrile-azole derivative was prepared by a nucleophilic ipso-nitro substitution reaction between 4-nitrophthalonitrile and fluconazole. The cyclotetramerization of phthalonitrile-azole with Zn(II) acetate in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) results in the formation of the ZnPcF as mixtures of constitutional isomers with 23% yield. Absorption and fluorescence spectroscopic studies were analyzed in different media. The results show that ZnPcF is lowly soluble in polar solvents or in reverse micellar systems. However, addition of HCl produce an increase in the monomerization of ZnPcF in N,N-dimethylformamide (DMF)/water (10% v/v) and in benzene/benzyl-n-hexadecyldimethyl ammonium chloride (BHDC) 0.1 M/water (W₀=10). A value of 0.19 was calculated for the fluorescence quantum yield (Φ_F) of this photosensitizer in DMF/water (10%)/HCl 1.2 mM. The photodynamic activity of ZnPcF was evaluated using 9,10-dimethylanthracene (DMA). An enhancement in the singlet molecular oxygen, O₂(¹Δ_g), production was obtained in acidified DMF/water or BHDC micellar system, which represent a appropriate system to induce monomerization of ZnPcF.