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.