A Convenient and Efficient Method for the Synthesis of a Novel Series of N‑Butyl‑1,4-oxazino[2’,3’:4,5]pyrano[3,2-c]quinolinones

Abstract

We design and describe here a simple route for the synthesis of a new multi heterocycle fused 1,4-oxazinopyranoquinolinones compatible with many functional groups. This method proceeds through various cyclic condensation reactions of (3-amino or 3-nitropyrano)[3,2-c]quinoline-2,5(6H)-dione precursors with different 1,2-bifunctional electrophiles. The synthesized compounds are confirmed by infrared (IR), proton ( 1 H) and carbon-13 ( 13 C) nuclear magnetic resonance (NMR) spectroscopy and electrospray ionization mass spectrometry (ESI-MS).

Convenient approach to novel tetracyclic-fused pyranoquinolinone compounds from 6-n‐butyl‐3‐amino-4-hydroxypyrano[3,2‐c]quinolinone

“…In the continuation of our earlier work on the synthesis of oxazinopyranoquinolinones, 28 the compound 2 was treated with triethyl orthoformate, under solvent free condition, to afford oxazinopyrano[3,2c]quinolinone 8 (Scheme 1). The IR spectrum of compound 8 showed the absence of OH function.…”