Synthesis and chemical reactivity of some pyranoquinolinone derivatives

Abstract

Vilsmeier-Haack formylation of 3-acetyl-4-hydroxy-1-methylquinolin- 2(1H)-one (2) and 3-(4-hydroxy-1-methy1-2-oxo-(1H)-quinolin-3-yl)-3- oxopropanoic acid (3) produced the novel 6-methyl-4,5-dioxo-5,6-dihydro-4Hpyrano[ 3,2-c]quinoline-3-carboxaldehyde (4) and 4-hydroxy-6-methyl-2,5-dioxo- 5,6-dihydro-2H-pyrano[3,2-c]quinoline-3-carboxaldehyde (5). Reactions of carboxaldehyde 4 with a diversity of nucleophilic reagents were studied and a variety of products were obtained via ring-opening ring-closure (RORC) sequence. The Chemical reactivity of carboxaldehyde 5 with a diversity of nitrogen nucleophilic reagents were studied and a variety of products were obtained. Some 1,3,4-oxadiazolyl/1,3,4-thiadiazolyl/benzothiazolyl/chromeno[2,3-b]pyridyl linked pyrano[3,2-c]quinoline-2,5(6H)-dione were efficiently synthesized. Structures of the new synthesized products were deduced on the basis of their analytical and spectral data. The newly synthesized compounds were screened for their antimicrobial activity.