Microwave-Assisted Synthesis of N,N-Dialkyl-P-Alkylphosphonamidic Anhydrides

Abstract

A new rapid, efficient, solvent-free, microwave-assisted, and high-yielding method for the synthesis of N,N-dialkyl-P-alkylphosphonamidic anhydrides has been developed. The method involves the use of 4-dimethylaminopyridine and water under microwave irradiation. The reaction of N,N-dialkylaminoalkyl/phenyl phosphonochloridates 2a–h with 4-dimethylaminopyridine (DMAP) gave pyridinium salts, which were converted into N,N-dialkyl-P-alkylphosphonamidic anhydrides 4a–h.

Keywords:

• N,N-Dialkylaminoalkyl/phenylphosphonochloridates
• N,N-dialkyl-P-alkylphos- phonamidic anhydrides
• 4-dimethylaminopyridine (DMAP)
• microwave irradiation

Acknowledgments

The authors thank to Ms. Mamta Sharma and Avik Mazumder for NMR analysis.

Notes

^a Product yields.

^{b 31}P NMR spectra were recorded in CDCl₃ at 162 MHz.