For the production of biodiesel from soybean oil (commercial edible grade), the [QPS]PW (5 wt.% to oil) was added to 1.0 g of soybean oil and 4.0 g of methanol at 65 °C. The experiment was prolonged for about 3 h.After completion of the reaction, the mixture was cooled and the catalyst was separated by decantation. The mixture was diluted with hexane, shaken for few minutes and agitated. Two layers were formed:the upper layer consisted of FAMEs, unreacted substrates and hexane,and the lower layer contained glycerin and the excess of methanol.