Indium Mediated Reduction of Nitro and Azide Groups in the Presence of HCl in Aqueous Media
Jung Gyu Lee, Kyung Il Choi, Hun Yeong Koh, Youseung Kim, Yonghan Kang, Yong Seo Cho*
Synthesis 2001, 81-84
Abstract
Indium mediated reduction of azide and nitro groups in the presence of HCl (1.5 equiv based on indium) at room temperature in aqueous THF successfully provided the corresponding amine in high to quantitative yields. Under the same reaction conditions, selective reduction of azide and nitro group in the presence of vinyl group could be accomplished.
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Ethyl 4-(2-Aminophenyl)but-2-enoate; Typical Procedure
To a solution of (4-nitrobut-1-enyl)benzene (1; 100 mg, 0.56 mmol) in aq THF (3 mL) was added indium powder (260 mg, 2.26 mmol) and concd HCl (300 µL). After stirring for 3 h at r.t., the pH of the reaction mixture was adjusted to 7 with solid NaHCO3, diluted with H2O and extracted with EtOAc, and the organic layer was dried (MgSO4) and concentrated in vacuo. The crude product was purified by a short column chromatography on neutral alumina (Scheme 2).
A Novel, Simple, Chemoselective and Practical Protocol for the Reduction of Azides Using In/NH4Cl
G. Vidyasagar Reddy*, G. Venkat Rao and D.S. Iyengar*
Tetrahedron Letters 40 (1999), 3937-3938
Abstract
A simple, mild and efficient method for the reduction of azides to amines using In / NH4Cl is described
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Typical procedure
To a solution of the azide (2 mmol) in ethanol (6 ml) was added indium powder (2 mmol) and NH4Cl (2 mmol). The resulting reaction mixture was heated at reflux with constant stirring (1-3 h). After completion of the reaction (monitored by TLC), the reaction mixture was brought to room temperature, diluted with ethylacetate (10 ml), stirred for 10 min and passed through a short pad of celite to give a clear solution. Removal of solvent under reduced pressure gave the amines in pure form.