ExistenceGuest
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Sod. dithionite
i need help for understanding the mechanism of reduction of this reducing agent ( i think it involve electron transfer without any hydrogen, but some
effervescence occur at beginning) i think it is SO2 from H2SO3 but i didn't find any textbook write or discuss it
thanx in advances
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fuming_nitric_acid
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http://www.organic-chemistry.org/abstracts/literature/894.sh...
A highly efficient and versatile method for the synthesis of benzimidazoles was achieved in one step via the Na2S2O4 reduction of o-nitroanilines in
the presence of aldehydes.
D. Yang, D. Fokas, J. Li, L. Yu, C. M. Baldino, Synthesis, 2005, 47-56.
http://www.organic-chemistry.org/abstracts/lit1/349.shtm
The hydrogenation of α,β-epoxy ketones can be mediated by a catalytic amount of BNA+Br- using Na2S2O4 as primary reducing agent to form the
corresponding β-hydroxy ketones in high yield. A radical mechanism has been proposed.
H.-J. Xu, Y.-C. Liu, Y. Fu, Y.-D. Wu, Org. Lett., 2006, 8, 3449-3451.
http://www.organic-chemistry.org/abstracts/lit1/762.shtm
Various azobenzenes have been reduced to the corresponding hydrazines by using an aqueous solution of sodium dithionite. The yield is generally
excellent, but two compounds, viz. 4,4-dimethoxyazobenzene and 2,2,4,4,6,6-hexamethylazobenzene, gave no hydrazine at all.
L. K. Sydnes, S. Elmi, P. Heggen, B. Holmelid, D. Malthe-Sørensen, Synlett, 2007, 1695-1696.
From Wikipedia:
http://en.wikipedia.org/wiki/Dithionite
2(S2O4)-2 + H2O → (S2O3)-2 + 2 (HSO3)−
Hope these help!
[Edited on 7-8-2008 by fuming_nitric_acid]
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