Concise Access to 2-Aroylbenzothiazoles by Redox Condensation Reaction between o-Halonitrobenzenes, Acetophenones, and Elemental Sulfur

Org Lett. 2015 May 15;17(10):2562-5. doi: 10.1021/acs.orglett.5b01182. Epub 2015 May 1.

Abstract

A wide range of 2-aroylbenzothiazoles 3 including some pharmacologically relevant derivatives can be obtained in high yields by simply heating o-halonitrobenzenes 1, acetophenones 2, elemental sulfur, and N-methylmorpholine. This three-component nitro methyl coupling was found to occur in an excellent atom-, step-, and redox-efficient manner in which elemental sulfur played the role of nucleophile building block and redox moderating agent to fulfill electronic requirements of the global reaction.

MeSH terms

  • Acetophenones / chemistry*
  • Benzothiazoles / chemical synthesis*
  • Benzothiazoles / chemistry
  • Benzothiazoles / pharmacology
  • Molecular Structure
  • Morpholines / chemistry
  • Nitrobenzenes / chemistry*
  • Oxidation-Reduction
  • Sulfur / chemistry*

Substances

  • Acetophenones
  • Benzothiazoles
  • Morpholines
  • Nitrobenzenes
  • 4-methylmorpholine
  • Sulfur