Efficient Reduction of Aromatic Nitro Groups in Water

  • Author: Sarah Maier
  • Published: 11 October 2021
  • Copyright: Wiley-VCH GmbH
  • Associated Societies: American Chemical Society (ACS), USA
thumbnail image: Efficient Reduction of Aromatic Nitro Groups in Water

Many pharmaceutical intermediates and drug molecules contain amino-substituted aromatic groups. Since the nitration of aromatic molecules is generally easily achieved, aromatic amines are often synthesized via the reduction of nitro groups. However, this can require high catalyst loadings.

Balaram S. Takale, Bruce H. Lipshutz, University of California, Santa Barbara, USA, and colleagues have developed a procedure for the reduction of aromatic nitro groups to the corresponding amines that only requires 0.4 mol% of a Pd/C catalyst and is run in water under an atmospheric pressure of H2. The aqueous medium is mixed with 2 wt% of the "designer" surfactant TPGS-750-M. The surfactant forms nanomicelles in which the reaction of the usually not water-miscible substrates takes place. After the reaction, the product can be easily isolated by filtration or extraction, and the surfactant and the catalyst can be reused.

The reaction proved efficient for a wide range of functionalized aryl- and heteroaryl nitro compounds, including various important pharmaceutical intermediates, which were cleanly reduced to the corresponding amines in high yields. The reduction was highly selective, and reducible functional groups like nitriles or ketones, as well as common protecting groups, remained intact. The approach could also be extended to various one-pot synthesis routes for different pharmaceutical intermediates, e.g., with an SNAr reaction or acylation following the nitro reduction in the same reaction vessel.



Article Views: 1296

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission and consult our permission guidance prior to making your request

Follow on Facebook Follow on Twitter Follow on YouTube Follow on LinkedIn Follow on Instagram RSS Sign up for newsletters

Magazine of Chemistry Europe (16 European Chemical Societies) published by Wiley-VCH