The Construction of Polycyclic Pyridones via Ring-Opening Transformations of 3-hydroxy-3,4-dihydropyrido[2,1-c][1,4]oxazine-1,8-diones

Abstract

This work describes the synthesis of 3-hydroxy-3,4-dihydropyrido[2,1-c][1,4]oxazine-1,8-diones, their tautomerism, and reactivity towards binucleophiles. These molecules are novel and convenient building-blocks for the direct construction of biologically important polycyclic pyridones via an oxazinone ring-opening transformation promoted with ammonium acetate or acetic acid. In the case of o-phenylenediamine, partial aromatization of the obtained heterocycles proceeded to form polycyclic benzimidazole-fused pyridones (33–91%).

Bioinspired Pyrano[2,3-f]chromen-8-ones: Ring C-Opened Analogues of Calanolide A: Synthesis and Anti-HIV-1 Evaluation

“…At least 9 out of 10 currently used anti-AIDS drugs are nitrogen-containing heterocyclic compounds [4]. The important role of heterocyclic compounds, especially quinoline [5] and pyrimidine [6] derivatives in the development of new anti-HIV drugs [7] is associated with their stability, conformational rigidity, convenience of synthesis [8,9], as well as the widest possibilities for tuning the properties by changing the size of cycles, types and number of heteroatoms, etc. [10].…”

“…Biomimetics 2024, 9, x FOR PEER REVIEW 2 of 20 quinoline [5] and pyrimidine [6] derivatives in the development of new anti-HIV drugs [7] is associated with their stability, conformational rigidity, convenience of synthesis [8,9], as well as the widest possibilities for tuning the properties by changing the size of cycles, types and number of heteroatoms, etc. [10].…”

Synthesis and Characterization of some new heterocyclic derivatives from terphthaldehyde and study of their biological activity

“…Bioactive drugs such as antibacterial 11 , antimicrobial, antiviral, anticancer 12 , anti-inflammatory 13 , anticoagulant, antidiabetic 14 analgesic, anti-Alzheimer's 15 and insecticide .As for the six membered, they are heterocyclic compounds that contain two heterocyclic atoms of nitrogen and oxygen. As for the oxazines, they are classified according to the location of the heterocyclic nitrogen atom in the hexagonal ring into (1,2-oxazine (16) , 1,3-oxazine 17 , 1,4-oxazine) 18 containing two heterocyclic atoms nitrogen and sulfur called thiazines 19 are classified according to the position of the heterocyclic nitrogen atom in the hexagonal ring into (1,2-thiazine, 1,3-thiazine, 1,4-Thiazine) 20…”