Kazimieras Anusevičius

Synthesis and antimicrobial activity of N-(4-chlorophenyl)-β-alanine derivatives with an azole moiety

N-(4-Chlorophenyl)-β-alanine was shown to be a useful synthetic intermediate for synthesis of azole heterocycles. Their structure was characterized by IR, mass, and NMR spectroscopy, and elemental analysis. Some of the synthesized compounds had antibacterial activity against Rhizobium radiobacter, as determined by use of the diffusion technique.Graphical Abstract

Unexpected transformation of ethyl 1-(4-chlorophenyl)-2-methyl-4-oxo-1,4,5,6-tetrahydropyridine-3-carboxylate and antibacterial activity of the products

The cyclization reaction of N-(4-chlorophenyl)-β-alanine, in the presence of piperidine as a catalyst, provided ethyl 1-(4-chlorophenyl)-2-methyl-4-oxo-1,4,5,6-tetrahydropyridine-3-carboxylate, which reactions with different hydrazines were carried out resulting in formation of a variety of tetrahydropyridine, dihydropyrazolone, and oxazole derivatives in good yields. 5-[2-[(4-Chlorophenyl)amino]ethyl]-4-(1-hydrazinylethylidene)-2,4-dihydro-3H-pyrazol-3-one was converted into a series of hydrazones, which provided tetrahydro-3H-pyrazolo[4,3-c]pyridin-3-one under treatment with acids. The structures of all synthesized compounds were confirmed by IR, 1H NMR, and 13C NMR spectroscopy. The structures of three compounds were unambiguously assigned by means of X-ray analysis data. Some of the synthesized compounds exhibited weak antibacterial activity.Graphical Abstract

Unexpected cyclization of N-aryl-N-carboxy-ethyl-β-alanines to 5,6-dihydrouracils

1-Substituted 5,6-dihydrouracils show certain biological activity which includes antitumor [1] and antiretroviral [2, 3] properties. 5,6-Dihydrouracil derivatives have also been used as adrenoblocking agents [4]. It is known that 1-aryl-5,6-dihydrouracils and their 2-thio analogs are prepared by the reaction of N-aryl--alanines or their esters with urea or alkali metal thiocyanates in acidic medium [5-8]. The reactions are generally performed in refluxing acetic acid with subsequent acidification of the reaction mixture with hydrochloric acid, in order to cyclize the intermediate N-aryl-N-carbamoyl(thiocarbamoyl)--alanines. We have found that N-aryl-N-carboxyethyl--alanines can be used in the synthesis of 1-aryl-5,6-dihydrouracils or their 2-thio analogs.

Nucleophilic ring opening of 1,4-disubstituted 2-pyrrolidones with hydrazine. Synthesis of azoles with a high antibacterial activity

3-(1 H -Benzimidazol-2-yl)-4-[(phenyl and 4-substituted phenyl)amino]butanohydrazides were synthesized in good yields by treating the corresponding 4-(1 H -benzimidazol-2-yl)-1-phenyl(substituted phenyl)-2-pyrrolidinones with the excess of hydrazine monohydrate. The utility of the newly synthesized hydrazides in the preparation of pyrroles, pyrazoles, oxadiazoles and triazoles has been demonstrated. All compounds were screened for their antibacterial activity. A significant antibacterial activity was found.

Synthesis and antibacterial activity of new N-substituted 7-amino-4-methyl-2H-chromen-2-ones

N-Substituted 7-amino-4-methyl-2H-chromen-2-ones containing one or two functionalized azole or azine moieties were synthesized. The structures of all synthesized compounds were confirmed by IR, 1H NMR, and 13C NMR spectroscopy. Some of the synthesized compounds exhibited weak antibacterial activity against Rhizobium radiobacter, Escherichia coli, and Xanthomonas campestris.