Synthesis of Heterocyclic Pyridine-Based Chalcones with Dimeric Structure

Three new heterocyclic chalcones containing pyridine moiety were synthesized and their chemical structures were determined via IR, 1H NMR and 13C NMR spectroscopy. General name of these compounds are α,ω-bis{3-(pyridin-3-yl)-1-(phenyl-4-oxy)prop-2-en-1-one}alkanes. The chalcones are dimers having a symmetrical structure and they can be differed by the alkyl spacer length (CnH2n, where n = 8, 10 or 12). Differential scanning calorimetry (DSC) technique was employed to study their phase transition behaviors.

Synthesis of Annelated P- and N-containing Heterocycles Based on Methyl 5-Aminothiophene-2-Carboxylate Derivatives

Derivatives of new bicyclic systems – 1H-thieno[3,2-c][1,5,2]oxazaphosphinine and 1,2-dihydrothieno[2,3-b][1,4]azaphosphinine have been obtained by phosphorylation of N-substituted derivatives of 5-amino-2-methoxycarbonylthiophene with phosphorus(III) tribromide. These heterocyclizations can be carried out in the basic medium and under mild conditions. The end reaction products were studied by means of chemical analysis, 1H and 31P NMR spectroscopy.

Synthesis of 2-Oxo(thio)-N,4-diaryl-1,2,3,4-tetrahydropyrimidine-5-carbothioamides

It was found that 2-acylthioacetamides enter Biginelli reaction with aromatic aldehydes and urea /thiourea forming 2-oxo(thio)-N,4-diaryl-1,2,3,4-tetrahydropyrimidine-5-carbothioamides. Under the influence of K3[Fe(CN)6] in alkaline environment, the expected 2-oxo(thio)-N,4-diaryl-5-(benzothiazole-2'-yl)-1,2,3,4-tetrahydropyrimidines were not been received while 2-oxo(thio)-N,4-diaryl-1,2,3,4-tetrahydropyrimidine-5-carbamides were the products of interaction.