Condensed O-, N-heterocycles by the transformation of azidoacrylates

Synthesis of furo[2',3':4,5]pyrrolo[1,2-d][1,2,4]triazine derivatives and their antibacterial activity

“…Melting points of products were determined on a Kofler hot plate apparatus and are uncorrected. (7) were synthesized following the published procedures 1,16 . The other chemicals were purchased from the suppliers as the highest purity grade.…”

“…Compound 3 displays in its 1 H NMR spectrum doublet due to H-2 proton at 7.79 ppm (J = 2.4 Hz), doublet of doublets of the pyrrole H-6 proton at 6.76 ppm (J = 2.4, 0.9 Hz) and doublet of the H-3 proton at 6.61 ppm (J = 2.4, 0.9 Hz). The most distinct signals of 3 in the 13 C NMR spectrum were the carbonyl carbons at 168.9 and 162.1 ppm.…”

“…The characteristic bands observed at 1641-1652 cm -1 in IR spectra correspond to the C=O groups at C-8. The carbonyl group at C-8 of triazine ring of 5a can be easily thionated 1,16 by reaction with phosphorus pentasulfide in pyridine to give thione 7 in high yield (85%). Subsequent reaction of 7 with methyl iodide in dimethylformamide in the presence of sodium hydride at room temperature for 1h led to 7-…”

“…Furo [3,2-b]pyrroles are isosteres of the indole ring system in which the benzene ring is replaced by the furan ring. Efficient synthetic routes to these heterocycles are of great interest [1][2][3][4] as the furo [3,2-b]pyrrole core has been found in compounds with diverse biological activities [5][6][7] or they are used as the fluorescent dyes 8 . Heterocyclic compounds containing five-and six-membered nitrogen heterocyclic rings have also attracted the attention due to the fact that they exhibit many biological interactions 9,10 .…”

NMR spectroscopic properties of furo[2′,3′:4,5]pyrrolo[1,2-d][1,2,4]triazine derivatives

“…Efficient synthetic routes to these heterocycles are of great interest (Krutošíková et al 1992;Beccalli et al 2008;Zhao et al 2014) as the furo [3,2-b]pyrrole core has been found in compounds with diverse biological activities (Sparey et al 2008;Fehér et al 2010) or they are used as the fluorescent dyes (Umezawa et al 2008). Heterocyclic compounds containing fiveand six-membered nitrogen heterocyclic rings have also attracted the attention due to the fact that they exhibit many biological interactions (Astakhina et al 2016).…”