11. Large amounts of propionic acid were once produced as a byproduct of acetic acid manufacture. 12. Products include acetic acid, propionic acid and butyric acid. 13. Propionic acid is also useful as an intermediate in the production of other chemicals, especially polymers.14. It is the ethyl ester of propionic acid . 15. The esters of propionic acid have fruit-like odors and are sometimes used as solvents or artificial flavorings. 16. In biogas plants, propionic acid is a common intermediate product, which is formed by fermenting propionic acid bacteria. 17. The main metabolite is inactive and is called " " N "-desisopropyl propionic acid " in the literature. 18. In biogas plants, propionic acid is a common intermediate product, which is formed by fermenting propionic acid bacteria. 19. The ethyl ester of propionic acid ( "'1 "') was brominated and then converted to the Wittig reagent using triphenylphosphine. 20. "' Propionic acid "'( from the salts and esters of propionic acid are known as propionates ( or propanoates ).
