Sulfamic Acid-Catalyzed One-Pot Room Temperature Synthesis of Biologically Relevant Bis-Lawsone Derivatives

Abstract

________________________________________________________________________ ABSTRACTA simple and energy-efficient green protocol for the synthesis of a series of biologically interesting functionalized bis-lowsone [i.e. 3,3'-(aryl/alkyl-methylene)bis(2-hydroxynaphthalene-1,4-dione)] scaffolds has been developed in the presence of sulfamic acid as an eco-friendly organocatalyst via one-pot pseudo-multicomponent reaction at room temperature. The salient features of the present protocol are mild reaction conditions, good to excellent yields, operational simplicity, energy-efficiency, high atom-economy, ecofriendliness, easy isolation of products and no column chromatographic separation. ______________________________________________________________________________

Sulfamic acid-catalyzed, environmentally benign synthesis of bis-tetronic acids at ambient temperature

“…On the other hand, there are also reports on sulfamic acid-catalyzed synthesis of bis-indolylalkanes and bis-pyrazoles [63,64], and when the current work on the synthesis of bis-tetronic acid was complete, there appeared a report on the application of sulfamic acid in the synthesis of bis-Lawsome (Fig. 1M) derivatives [65]. However, to the best of our knowledge, there are no reports on the use of sulfamic acid in the synthesis of bisScheme 2 Sulfamic acid catalyzed synthesis of spirocyclic bis-tetronic acids 5 Scheme 3 Plausible mechanism of sulfamic acid-catalyzed synthesis of bis-tetronic acids Sulfamic acid-catalyzed, environmentally benign… tetronic acids.…”

Design for carbon–carbon bond forming reactions under ambient conditions

“…[192][193][194][195] Brahmachari and his group reported a straightforward and efficient pseudo three-component onepot synthesis of a series of substituted bis(6-aminouracil-5-yl)methanes 86 in good yields using either ceric ammonium nitrate (CAN) 196 or sulfamic acid 197 as commercially available, inexpensive and eco-friendly catalyst from the reaction of 6-aminouracils (85) and diverse aldehydes (1) in aqueous ethanol at room temperature (Scheme 30). 209 The plausible mechanism for this transformation involving a Knoevenagel-type condensation is presented in Scheme 32. Scheme 30.…”

“…Glycine-catalyzed one-pot multicomponent synthesis of 2-amino-3-cyano-4Hchromenes(209) in water Ziarati et al390 developed an efficient protocol for the synthesis of 2-aryl-5-methyl-2,3dihydro-1H-3-pyrazolones (211) with the aid of synergetic effect of ultrasonication and Cu-nano catalysis from a four-component one-pot condensation reaction of hydrazines, ethyl acetoacetate, aldehydes and β-naphthol in water (Scheme 80). Glycine-catalyzed one-pot multicomponent synthesis of 2-amino-3-cyano-4Hchromenes(209) in water Ziarati et al390 developed an efficient protocol for the synthesis of 2-aryl-5-methyl-2,3dihydro-1H-3-pyrazolones (211) with the aid of synergetic effect of ultrasonication and Cu-nano catalysis from a four-component one-pot condensation reaction of hydrazines, ethyl acetoacetate, aldehydes and β-naphthol in water (Scheme 80).…”

A New Strategy for the Synthesis of Nonsymmetrical 3,3’-(Aryl/alkyl- methylene) bis-2-hydroxy-1,4-naphthoquinones and Their Cytotoxic Effects in PC3 Prostate Cancer Cells

“…However, no biological result against tumor cells is shown in this publication. Brahmachari 25 synthesized a series of 3,3'-(aryl/alkyl-methylene) bis(2-hydroxynaphthalene-1,4-dione) derivatives and assayed them for pro-apoptotic activity in five distinct cancer cell lines and found one compound effective in inducing apoptosis in human glioma cells (CCF-4). 24 Although several methods for the synthesis of these derivatives have been reported, most of them suffer limitations regarding selectivity in forming nonsymmetrical 3,3'-(methylene)bis-2-hydroxy-1,4-naphthoquinones.…”