A domino knoevenagel-phospha-michael reaction: One-pot synthesis of novel organophosphonates in the presence of multi-walled carbon nanotube‒CO‒NH(CH₂)₂NH-SO₃H as catalyst

We report a one-pot method for the synthesis of various substituted 1,3-dimethyl-2,4,6-trioxohexahydropyrimidin-5-yl phosphonate derivatives via phosphorus-carbon bond formation through domino Knoevenagel–phospha–Michael reaction. Multi-walled carbon nanotube‒CO‒NH(CH₂)₂NH-SO₃H was used as an acidic heterogeneous catalyst. The catalyst could be used four times without losing its catalytic activity. The structures of the products were determined by FT-IR spectra, ¹H-, ¹³C- and ³¹P- Nuclear Magnetic Resonance and elemental analysis. Recovery and reusability of catalyst, simplicity, applicability, good reaction time and good yields of products are the benefits of this work.