Microwave-assisted Piloty-Robinson synthesis of 3,4-disubstituted pyrroles

J Org Chem. 2007 May 11;72(10):3941-4. doi: 10.1021/jo070389+. Epub 2007 Apr 14.

Abstract

The synthesis of N-acyl 3,4-disubstituted pyrroles can be accomplished directly from hydrazine and an aldehyde via a Piloty-Robinson pyrrole synthesis. The use of microwave radiation for the cyclization and pyrrole formation greatly reduces the time necessary for this process and facilitates moderate to good yields from hydrazine for the corresponding 3,4-disubstituted products (5-12). By simple hydrolysis, the free N-H pyrroles can be accessed after the Piloty-Robinson reaction and then used directly in the synthesis of octaethylporphyrin (H2OEP, 14) and octaethyltetraphenylporphyrin (H2OETPP, 15).

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Benzene / chemistry
  • Hot Temperature
  • Microwaves*
  • Molecular Structure
  • Pyrroles / chemical synthesis
  • Pyrroles / chemistry*

Substances

  • Pyrroles
  • Benzene