Utilization of vanillin to prepare sulfated Calix[4]resorcinarene as efficient organocatalyst for biodiesel production based on methylation of palmitic acid and oleic acid.

Recently, biodiesel production from palm oils has been thoroughly investigated to substitute crude oil due to its scarcity. However, the biodiesel production process is time-consuming due to its slow kinetics; thus, concentrated sulfuric acid has been used to fasten the reaction process in some industries. Unfortunately, sulfuric acid is a toxic, corrosive, and non-environmentally friendly catalyst.