Tin(ii) chloride dihydrate/choline chloride deep eutectic solvent: redox properties in the fast synthesis of N-arylacetamides and indolo(pyrrolo)[1,2-a]quinoxalines

Abstract

Physicochemical and redox properties of SnCl2·2H2O/ChCl deep eutectic solvent were studied and applied in the synthesis of anilines, N-arylacetamides and indolo(pyrrolo)[1,2-a]quinoxalines starting from nitroaromatic compounds.

Molecular and Spectroscopic Insights into a Metal Salt-Based Deep Eutectic Solvent: A Combined Quantum Theory of Atoms in Molecules, Noncovalent Interaction, and Density Functional Theory Study

“…However, bands below 900 cm –1 are associated with Sn–Cl bonds. These spectra are consistent with the previously published ones . However, at 3450 cm –1 , a broad vibrational band is observed that is attributed to O–H stretching.…”

“…These spectra are consistent with the previously published ones. 56 However, at 3450 cm −1 , a broad vibrational band is observed that is attributed to O−H stretching. This band broadens as the interaction between QAS ions weakens and chloride pledges new interactions with the metal salt dimers, designating the formation of electrostatic interactions.…”

Recent Examples in the Synthesis and Functionalization of C−H Bonds in Pyrrolo/Indolo [1,2‐a]Quinoxalines

“…Ochoa‐Puentes and co‐workers have revealed that a rapid reduction of 2‐( N ‐pyrrolyl)nitroarenes could be obtained in the presence of SnCl 2 ⋅ 2H 2 O/choline chloride (ChCl) eutectic mixture [20] . Such the simple tactic allowed for the annulation of aldehydes to afford C4‐substituted pyrrolo[1,2‐ a ]quinoxalines that featuring an array of functionalities (Scheme 21).…”

“…Ochoa-Puentes and co-workers have revealed that a rapid reduction of 2-(N-pyrrolyl)nitroarenes could be obtained in the presence of SnCl 2 ⋅ 2H 2 O/choline chloride (ChCl) eutectic mixture. [20] Such the simple tactic allowed for the annulation of aldehydes to afford C4-substituted pyrrolo[1,2-a]quinoxalines that featuring an array of functionalities (Scheme 21). Although the mechanism has been still disputable at that moment, control experiments somewhat implied that the deep eutectic solvent only participated in the reduction, not the cyclization.…”

Electrochemical C-H Halogenations of Enaminones and Electron-Rich Arenes with Sodium Halide (NaX) as Halogen Source for the Synthesis of 3-Halochromones and Haloarenes

“…7, 133.5, 130.2, 128.5, 126.6, 125.5, 123.5, 123.0, 117.4, 101.8. 4-Bromoisoquinolin-1-amine (5d 7, 143.5, 135.1, 131.8, 127.0, 125.5, 125.1, 119.2, 104.9 4-Bromoaniline (5e). 24 Elution with 10:1 (v/v) mixed petroleum ether and ethyl acetate. Yield 40%, 20.5 mg; white solid; mp 62−63 °C; 1 H NMR (400 MHz, DMSO-d 6 ): δ 7.17 (d, J = 8.8 Hz, 2 H), 6.56 (d, J = 8.8 Hz, 2 H), 5.31 (s, 2 H); 13 C{ 1 H} NMR (100 MHz, DMSO-d 6 ): 148.5,131.8,116.2,.…”