Synlett 2004(10): 1835-1837  
DOI: 10.1055/s-2004-830847
LETTER
© Georg Thieme Verlag Stuttgart · New York

Efficient Reductions of Nitroarenes with SnCl2 in Ionic Liquid

Prithwiraj De*
Department of Chemistry, University of Kalyani, Kalyani-741235, India
e-Mail: raj@klyuniv.ernet.in;
Further Information

Publication History

Received 10 March 2004
Publication Date:
15 July 2004 (online)

Abstract

Mild, eco-friendly and fast reductions of nitroarenes to aminoarenes have been accomplished using stannous chloride dihydrate in ionic liquid tetrabutylammonium bromide (TBAB) that provides unsolvated nucleophilic bromide ion. Improved yields, lower reaction time, generality, and a less demanding work-up procedure are the notable features of this protocol.

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Representative Procedure for Reduction of Nitroarenes with SnCl 2 in Ionic Liquid: Nitroarene (2 mmol) was mixed with TBAB (1 g) with stirring and to this mixture was added SnCl2·2H2O (1350 mg, 6 mmol, 3 equiv). The mixture was stirred until a clear melt resulted. Then it was kept on water bath at 90 °C for completion (TLC monitoring) and extracted with Et2O (3 × 5 mL). The combined organic layer was washed with H2O, brine and dried over anhyd Na2SO4. Removal of solvent gave the crude product, which was purified by column chromatography over silica gel to furnish aminoarene exclusively.