LaCl3·7H2O: An Efficient Catalyst for the Synthesis of Phosphinates (Michaelis—Arbuzov Reaction) under Neat Conditions and Their Potential Antimicrobial Activity.

An expeditious neat procedure was developed for the synthesis of a series of new methyl phenyl heterocyclic phosphinates (3a–l) through Michaelis–Arbuzov reaction by the reaction of various heterocyclic halides (Cl or Br) (1a–l) with dimethyl phenylphosphonite (2) under N2 atmosphere using a heterogeneous catalyst, LaCl3.7H2O. The advantages of the developed procedure are good yields (80–89%) of the products, less reaction time (2–3 h), avoiding toxic catalysts and harmful solvents and easy work-up procedure. Further, antimicrobial activity of the synthesized compounds was evaluated at different concentrations 50, 100 and 150 μg/mL. Biological data revealed that compounds 3i, 3j and 3h, 3j exhibited potential antibacterial and antifungal activities, respectively, while the rest of the compounds showed moderate antimicrobial activity.