Substituted Quinolinones, Part 11: Efficient Synthesis of Different 3‐(4‐Arylidene and Hetarylidene‐5‐oxopyrazolin‐3‐yl) quinolin‐2‐ones

Novel heterocyclic derivatives of pyrano[3,2-c]quinolinone from 3-(1-ethy1-4-hydroxy-2-oxo-2(1H)-quinolin-3-yl)-3-oxopropanoic acid

“…For example, degradation of 1 in boiling 2N sodium hydroxide aqueous solution yielded 1-ethyl-3-acetyl-4-hydroxyquinolin-2(1H)-one through pyrone ring opening, followed by decarboxylation [11,12]. In continuation to previous research on 4-hydroxyquinolin-2(1H)-ones [13][14][15][16][17][18], the present paper reports the synthesis of the new 3-(1-ethy1-4-hydroxy-2-oxo-2(1H)-quinolin-3-yl)-3-oxo-propanoic acid (2) and the study of its chemical reactivity towards some ortho-hydroxyaldehydes and ortho-aminoaldehydes, in search of new quinolinone derivatives of potential biological activity.…”

3-Formylchromones as diverse building blocks in heterocycles synthesis

“…Similarly, condensation of 3-formylchromone (1a) with pyrazol-3-ylquinoline derivative 110 in glacial acetic acid containing sodium acetate afforded chromenylpyrazolinone 111 (Scheme 54) [82].…”

Substituted quinolinones 15*. Preparation and enzymatic activity of some pyrazoloazines linked to the 4-hydroxy-1-methyl- quinolin-2(1H)-one moiety

“…In view of these important applications of the three classes of pyrazoloazines it is thought that combination of both quinolinone and some pyrazoloazine moieties in one-molecular frame may lead to a new biologically active series of heterocyclic compounds. In continuation of our program dealing with the synthesis and study of new pyrazoles [28,29] and substituted quinolinones [30,31], the present work focused on the synthesis of some fused pyrazoloazine derivatives incorporating the 4-hydroxy-1-methylquinolin-2(1H)-one moiety as the substituent attached to pyrazolinone. An important regulating effect of quinolinones on the activity of α-amylase in efficient conversion of starch to D-glucose has been described previously [32,33].…”

“…The Knoevenagel condensation reaction of two selected aldehydes, 4-chlorobenzaldehyde and pyridine-2-carbaldehyde, with 4-hydroxy-1-methyl-3-(5-oxo-4,5-dihydro-1H-pyrazol-3-yl)quinolin-2(1H)-one (1) in the presence of fused sodium acetate and glacial acetic acid is considered an efficient procedure to obtain 3-[4-arylidene-5-oxo-4,5-dihydro-1H-pyrazol-3-yl]-4-hydroxy-1-methylquinolin-2(1H)-ones 2a and 2b [30,31]. Michael addition of pyrazolinone 1 to 3-aryl-2-cyanoacrylamides and/or thioacrylamides in the presence of piperidine as a base catalyst furnished heterocyclized fused systems, pyrazolo [3,4- …”