Efficient synthesis of 1,2-bis(alkoxycarbonyl)pyrazol-3-ones from 2,3-allenoic acids, azodicarboxylates and PPh3

Chem Commun (Camb). 2014 Feb 14;50(13):1537-9. doi: 10.1039/c3cc48215d.

Abstract

An efficient cascade reaction of 2,3-allenoic acids with dialkyl azodicarboxylate in the presence of PPh3 affording 1,2-bis(alkoxycarbonyl)pyrazol-3-ones in moderate yields has been developed. The reaction may proceed via the intramolecular Michael addition of the expected 2,3-allenoyl hydrazines.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azides / chemistry
  • Carboxylic Acids / chemistry*
  • Cyclization
  • Hydrazines / chemistry
  • Models, Molecular
  • Pyrazoles / chemical synthesis*
  • Pyrazoles / chemistry

Substances

  • Azides
  • Carboxylic Acids
  • Hydrazines
  • Pyrazoles