In summary

In summary, we have demonstrated that the reactions of a urea/thiourea derivatives with triethyl phosphite under solvent free condition in the presence of nano BF3.SiO2 using microwave irradiation proceeded rapidly and cleanly to give the corresponding substituted phosphonates. Mild, non-hazardous and environment friendly reaction conditions, recyclability of the catalyst, good selectivity giving excellent yield in short reaction time are significant advantages of this method. The compounds 5d and 5h and 5j showed promising antibacterial activity when compared with the remaining title compounds, and were closer to standard drug. The compounds 5a and 5c showed exhibited potent antifungal activity against the two tested fungal strains when compared with the remaining compounds.