Aminophosphinic Acids in a Pyridine Series, Part 2: Synthesis of 2-, 3-, and 4-Pyridyl Derivatives of 1-(Benzylamino)-methyl-H-phosphinic Acids

Abstract

New 2-pyridyl, 3-pyridyl, and 4-pyridyl derivatives of 1-[N-(benzyl)amino]-methyl-H-phosphinic acid were prepared by the addition of bis(trimethylsilyl)phosphonite to the corresponding imines and subsequent methanolysis of the addition products. Treatment of the 2-pyridyl- and 1-(4-pyridyl)-1-(benzylamino)-methyl-H-phosphinic acids with aqueous mineral acids leads to cleavage and formation of the corresponding secondary amines and phosphorous acid (H ₃ PO ₃ ).

Keywords:

• Aldimines
• aminophoshinic acids
• bis(trimethylsilyl)phosphonite (BTSP)
• phosphinic acids
• pyridines

Acknowledgments

Dedicated to Professor Marian Mikołajczyk, CBMiM PAN in Łódź, Poland, on the occasion of his 70th birthday.

The authors are thankful to the Faculty of Chemistry, Wrocław University of Technology, Wrocław, Poland for financial support.

Notes

^a Yield given for pure diastereomer.