Synthesis and evaluation of the antioxidant activity of 3-pyrroline-2-ones: experimental and theoretical insights

Abstract

Derivatives of 3-hydroxy-3-pyrroline-2-one were effectively synthesized via multicomponent reactions and exhibited potential HO˙ radical scavenging activity.

Synthesis and structural determination of some 1,5-disubstituted-4-ethoxycarbonyl-3-hydroxy-3-pyrroline-2-one derivatives containing nitro group

“…The optimal reaction conditions for the synthesis of 1,5-diphenyl-4-ethoxycarbonyl-3-hydroxy-3-pyrroline-2one [10] were applied to yield nitro group containing 1,5-disubstituted-4-ethoxycarbonyl-3-hydroxy-3-pyrroline -2-ones (Figure 3, Table 1). Furthermore, due to low solubility of nitro group containing aromatic compounds in absolute ethanol, toluene was also added to the reaction mixture to dissolve all starting material containing nitro group (-NO2).…”

“…Along with compounds of natural origin, non-natural polysubstituted 3-pyrroline-2-ones have been synthesized and evaluated for their biological and pharmacological activities such as antioxidant [10], [11], [12], antibacterial [13], [14], anticancer [15], [16], [17], as well as anti-HIV-1 [18] and inflammatory [19]. Therefore, there has been increasing attention to the synthesis of polysubstituted 3-pyrroline-2-ones, and especially 1,5-disubstituted-4ethoxycarbonyl-3-hydroxy-3-pyrroline-2-ones [20].…”

“…1,5-Disubstituted-4-ethoxycarbonyl-3-hydroxy-3-pyrroline-2-ones have been synthesized via MCRs of substituted benzaldehydes, amines, and diethyl acetylenedicarboxylate [22], [23], [24], [25]. In addition, 1,5-disubstituted-4-ethoxycarbonyl-3hydroxy-3-pyrroline-2-ones could also be synthesized via MCRs of substituted benzaldehydes, amines and sodium diethyl oxalacetate [26], [10]. However, the abovementioned five-membered ring heterocycles containing nitro group (-NO2) still need to be explored more by synthetic organic chemists.…”

“…The initial step in MCRs to synthesize 1,5-disubstituted-4-ethoxycarbonyl-3-hydroxy-3-pyrroline-2-ones (4a-c) takes place via the reaction between substituted benzaldehyde (1a-c) and 4-nitroaniline (2a) to yield imine (5) [27] (Figure 4). Therefore, the presence of substituent groups attached to the benzene ring in the structure of starting materials will affect both the rate and the yield of imine formation reaction [10].…”

“…Consequently, there was a dramatic decrease in the yield of 1-(4-nitrophenyl)-5-phenyl-4-ethoxycarbonyl-3-hydroxy-3-pyrroline-2-one (4a), 38% (Table 1), as compared to the synthesis of 1,5-diphenyl-4-ethoxycarbonyl-3-hydroxy-3pyrroline-2-one, 86% [10]. Moreover, the yields of 4b and 4c were also lower than that of 1,5-diphenyl-4ethoxycarbonyl-3-hydroxy-3-pyrroline-2-one [10].…”