Nucleophilic substitution and ring transformation reactions with 4-chloro-6-ethyl-3-nitropyrano[3,2-c]quinoline-2,5(6H)-dione

Abstract

4-Chloro-6-ethyl-3-nitropyrano[3,2-c]quinoline-2,5(6H)-dione (3) was obtained by nitration followed by chlorination of 4-hydroxypyranoquinoline-2,5-dione 1. Substitution reactions of compound 3 with various nucleophiles, namely: sodium azide, amines, thiophenol and malononitrile, led to a series of novel 4-sustituted-3-nitropyranoquinolinones. Also, nucleophilic reactions of compound 3 with hydrazine, cyanoguanidine and S-methylisothiourea, involving ring opening-ring closure of the pyranoquinolinedione nucleus, are described.

Studies on Quinolin-2(1H)-One Derivatives: Synthetic Access to Pyrano[3,2-c] Quinoline and 3-Substituted Quinoline Derivatives

“…4-Hydroxyquinolin-2(1H)-ones represents one of the most important class of heterocycles possessing wide spectrum of biological activities [1][2][3][4][5][6]. Also, they have occupied a unique place in the medicinal and biological chemistry due to their diverse pharmacological displays as antitumor [7], antimicrobial [8], antibacterial [9] and antischistosomal agents [10].They are also useful intermediates in the manufacture of azo dyestuffs,that can be used for dyeing both naturally occurring and synthetic fibres [11] .…”

Studies on 2(1H)-Quinolone Derivatives: Synthetic Access to Pyrano[3,2-c] Quinoline and 3-Substituted Quinoline Derivatives

“…4-Hydroxyquinolin-2(1H)-ones represents one of the most important class of heterocycles possessing wide spectrum of biological activities [1][2][3][4][5][6]. Also, they have occupied a unique place in the medicinal and biological chemistry due to their diverse pharmacological displays as antitumor [7], antimicrobial [8], antibacterial [9] and antischistosomal agents [10]. They are also useful intermediates in the manufacture of azo dyes [11].…”