Novel synthesis of 5-amino-3-bromo-1-(tert-butyl)-1H-pyrazole-4-carbonitrile: a versatile intermediate for the preparation of 5-amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides

Org Lett. 2012 Aug 3;14(15):3906-8. doi: 10.1021/ol301655f. Epub 2012 Jul 18.

Abstract

A simple, novel, and efficient route for the synthesis of 5-amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides 1 has been devised. Preparation of pyrazole bromide 3 from potassium tricyanomethanide can be accomplished in only two steps in good yield and features a selective Sandmeyer reaction on the corresponding diaminopyrazole. This allows for a more versatile synthesis of 5-amino-3-aryl-1-(tert-butyl)-1H-pyrazole-4-carboxamides 1 than was previously possible.

MeSH terms

  • Amides / chemical synthesis*
  • Amides / chemistry
  • Combinatorial Chemistry Techniques
  • Hydrocarbons, Brominated / chemical synthesis*
  • Hydrocarbons, Brominated / chemistry
  • Molecular Structure
  • Pyrazoles / chemical synthesis*
  • Pyrazoles / chemistry
  • Stereoisomerism

Substances

  • Amides
  • Hydrocarbons, Brominated
  • Pyrazoles