The hot-air oven dried 50 mL double-neck round bottom flask was charged with solid powder of PTE-II (500 mg, 0.524 mmol) under nitrogen atmosphere at ambient temperature followed by the dropwise addition of 2-aminoethanol (0.26 mL, 4.2 mmol) and allowed the mixture to stir under neat reaction conditions. Then, the reaction temperature was raised to 120 o C allowed it to stir for next 4 hours under continuous flow of nitrogen. Completion of the reaction monitored by TLC from the consumption of the reactant PTE-I, there was unreacted starting material, so again 2-aminoethanol (0.26 mL, 4.0 mmol) was added to the stirring reaction mixture and continued for next 4 hours under similar conditions.