One-Pot Efficient Synthesis of Fully Substituted 1,3,4-Oxadiazole Derivatives from (N-Isocyanimino)triphenylphosphorane, Carboxylic Acids, and Aromatic Bis-Aldehydes

Abstract

Reactions of (N-isocyanimino)triphenylphosphorane with aromatic bis-aldehydes (isophthalaldehyde and terphthalaldehyde) in the presence of aromatic (or heteroaromatic) carboxylic acids proceed smoothly at room temperature and in neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in good yields. The reaction proceeds smoothly and cleanly under mild conditions, and no side reactions were observed.

Keywords:

• Aromatic carboxylic acid
• aza-Wittig reaction
• heteroaromatic carboxylic acid
• (N-isocyanimino)triphenylphosphorane
• 1,3,4-oxadiazole

ACKNOWLEDGMENTS

This research was supported by Zanjan University and the Iranian National Science Foundation (INSF).

Notes

^a Isolated yields.