Novel salicylaldehyde-based mineral-supported expeditious synthesis of benzoxazin-2-ones.
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).
Yadav
Lal Dhar S
LD
Department of Chemistry, University of Allahabad, Allahabad-211002, India. lds-yadav@hclinfinet.com
Kapoor
Ritu
R
D000447:Aldehydes / Q000737:chemistry*; D048588:Benzoxazines / Q000138:chemical synthesis*; D002384:Catalysis; D006835:Hydrazones / Q000737:chemistry; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D004364:Pharmaceutical Preparations
D000447:Aldehydes; D048588:Benzoxazines; D006835:Hydrazones; D007202:Indicators and Reagents; D004364:Pharmaceutical Preparations; C013243:salicylaldehyde