Abstract
Raney-Ni/EtOH reduction of different N-sulfonylimines provides a new entry for synthesizing sulfonamides in good yields under mild conditions. This protocol, which does not require additional hydrogen, constitutes a cheap, safe, and easy-to-handle alternative procedure to prepare α-branched sulfonamides.
GRAPHICAL ABSTRACT
ACKNOWLEDGMENTS
We thank the DGYCT (CTQ2009-12168-BQU) and Comunidad Autónoma de Madrid (S2009/PPQ-1634) for financial support. J. A. F.-S. thanks Comunidad Autónoma de Madrid for a predoctoral contract.
Notes
a Measured by 1H NMR. b Only decomposition was observed.
a 1.5 g of Raney Ni were used.
b Reflux was necessary.
c Complex mixture (see text).
d Na2SO4 was used as water scavenger.
a A 50% conversion was obtained after 10 h at rt.
b Na2SO4 was used as water scavenger.