Novel salicylaldehyde-based mineral-supported expeditious synthesis of benzoxazin-2-ones

J Org Chem. 2004 Nov 12;69(23):8118-20. doi: 10.1021/jo0492315.

Abstract

One-pot montmorillonite K-10 clay supported reactions of either salicylaldehyde/2-hydroxyacetophenone hydrazones and aryl-/alkylureas or salicylaldehydes/2-hydroxyacetophenone and 4-aryl-/alkylsemicarbazides expeditiously yield 3,4-dihydro-4-hydrazino-2H-benz[e]-1,3-oxazin-2-ones (9) via cycloisomerization of the intermediate salicylaldehyde/2-hydroxyacetophenone 4-aryl-/alkylsemicarbazones (5) under solvent-free microwave irradiation. Under the same conditions, hydrazines (9) readily underwent reductive dehydrazination on alumina-supported copper(II) sulfate to furnish 2H-benz[e]-1,3-oxazin-2-ones (10).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehydes / chemistry*
  • Benzoxazines / chemical synthesis*
  • Catalysis
  • Hydrazones / chemistry
  • Indicators and Reagents
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Pharmaceutical Preparations

Substances

  • Aldehydes
  • Benzoxazines
  • Hydrazones
  • Indicators and Reagents
  • Pharmaceutical Preparations
  • salicylaldehyde