Substituted quinolinones. Part 13 a convenient route to heterocyclization reactions with 3‐substituted 4‐hydroxyquinolin‐2(1H)‐one

Abstract

The reactivity of 3‐[(dimethylamino)prop‐2‐enoyl]‐4‐hydroxyl‐1‐methylquinolin‐2(1H)‐one (2) towards different nucleophilic and electrophilic reagents was investigated. The convenient synthesis of several 3‐heterocyclyl‐quinolinones such as 3‐pyridazinyl‐ 10, 11, 3‐pyranyl 19a,b and 3‐pyrazolylquinolinones 20a,b, 22, 26a,b, 27a,b, 31 and 33 has been described starting from the 3‐acetylquinolinone 1 and enaminone 2. In addition, certain heterocyclo[c]quinolinones such as pyrimido‐ 12, 14 pyrano‐ 3, 17a,b and pyrazolopyranoquinolinone 29 were obtained in good yields.

An Efficient New Route for the Synthesis of Some 3‐Hterocyclylquinolinones via Novel 3‐(1,2‐Dihydro‐4‐hydroxy‐1‐methyl‐2‐oxoquinolin‐3‐yl)‐3‐oxopropanal and Their Antioxidant Screening

“…Hydrolysis of compound 3 using (1 N ) hydrochloric acid solution at room temperature afforded the newly synthesized 3‐(1,2‐dihydro‐4‐hydroxy‐1‐methyl‐2‐oxoquinolin‐3‐yl)‐3‐oxopropanal ( 5 ) in 70% yield. Interestingly, alkaline hydrolysis of our reported 6‐methyl‐4 H ‐pyrano[3,2‐ c ]quinoline‐4,5(6 H )‐dione ( 4 ) furnished the same desired aldehyde 5 but in a less yield of 56%. Structure of compound 5 was confirmed on the basis of its spectral data.…”

Studies on the chemical behavior of 3-(nitroacetyl)-1-ethyl-4-hydroxyquinolin-2(1H)-one towards some electrophilic and nucleophilic reagents

“…[14][15][16] Therefore, formylation of compound 4 under Vilsmeier-Haack conditions (DMF/ POCl 3 ) resulted in introducing the formyl group at the active methylene carbon giving 3-(1-ethyl-4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)-2-nitro-3-oxopropanal (9) (Scheme 4). The IR spectrum of compound 9 showed a characteristic absorption band at 1735 cm -1 which might be attributed to the C=O of the aldehydic function.…”

Synthesis of some new pyrazolylfuropyrimidinethiones and triazolofuropyrimidinethiones

“…Therefore, compound 3 reacted with diethyl malonate, ethyl acetoacetate and acetylacetone in absolute ethanol containing catalytic amount of triethylamine giving pyrazolylfuropyrimidinethiones (12)(13)(14). The structures of compounds 12-14 were established from their correct elemental analyses and spectroscopic data.…”

“…They showed antifungal [4], antifolate [5], antibacterial [6], antitumor [7], antiviral [8], and anti HCMV [9] (antihuman cytomegalovirus). As a part of our program directed to develop the chemistry of enaminones [10], and pyrimidines [11][12][13][14][15][16], the present investigation deals with the use of 2-amino-4,5-diphenylfuran-3-carbonitrile (1) [17], as a starting material for the synthesis of the target pyrazolylfuropyrimidinethiones and furotriazolopyrimidinethiones.…”