Scalable, sustainable and catalyst-free continuous flow ozonolysis of fatty acids

A simple and efficient catalyst-free protocol for continuous flow synthesis of azelaic acid is developed from the renewable feedstock oleic acid. An ozone and oxygen mixture was used as the reagent for oxidative cleavage of double bond without using any metal catalyst or terminal oxidant. The target product was scaled up to more than 100 g with 86% yield in a white powder form. Complete recycling and reuse of the solvent were established making it a green method. The approach is significantly energy efficient and also has a very small chemical footprint. The methodology has been successfully tested with four fatty acids making it a versatile platform that gives value addition from renewable resources.