Cyclocondensation Of 4-Hydroxy-5,6-Diaminopyrimidine With α,β-Dihalochalcones

Article abstract of DOI:10.1007/BF00538070

The condensation of 4-hydroxy-5,6-diaminopyrimidine with 1,3-diaryl-2,3-dihalopropanones and with dibenzoylacetylenes was used to obtain derivatives of 1H-pyrimido<4,5-b>-1,5-diazepine and pyrimido<4,5-b>pyrazine, respectively.Their spectral characteristics were studied, and the directions in the formation of 7- and 6-membered heterocycles were determined.The synthesized pyrimido<4,5-b>pyrazines exist in the form of two tautomeric species - enaminocarbinol and enol forms, with an intramolecular hydrogen bond of the chelate type.