Propanephosphonic Acid Anhydride–Mediated Cyclodehydration of Maleic Acid Monoamides

Abstract

Propanephosphonic acid anhydride (T3P) has been proposed as a novel reagent for the preparation of maleic acid isoimides from the corresponding monoamides. A series of substituted aromatic and aliphatic isoimides have been prepared in good yields. The main advantage of this synthetic method is the use of environmentally benign, cost-efficient reagents and solvents, which are also safer to handle than the ones employed previously.

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GRAPHICAL ABSTRACT

Keywords:

• Cyclodehydration
• green synthesis
• maleic acid isoimides
• propanephosphonic acid anhydride

Notes

Note. Dehydrating agent used:

^a Dicyclohexylcarbodiimide.

^b Cyanuric chloride/triethylamine.

^c Ethylchloroformate/triethylamine.

^d 2-Chloro-1,3-dimethylimidazolinium chloride/triethylamine.