Synthesis of 12-phosphonooleic acid and surfactant properties of its sodium salt

Methyl ricinoleate (9-cis, 12-hydroxyoctadecenoate) was transformed to 12-bromo/iodo-oleate via methyl 12-mesyloxyoleate by homoallylic displacement reaction. The halooleate was reacted with triethyl phosphite to give methyl 12-diethyl phosphonooleate via the Michaelis-Arbuzov reaction under modified conditions. The phosphonooleate was hydrolyzed to 12-phosphonoleic acid using conc. hydrochloric acid. The compounds were characterized by phosphorus estimation and a combination of IR,¹H-NMR and¹³C-NMR spectroscopic techniques. The 12-phosphonooleic acid was neutralized to its sodium salt, and the salt was then studied for its surfactant properties. The sodium phosphonooleate was found to be superior to sodium salts of sulfate and phosphate esters of castor oil, and comparable to sodium lauryl sulfate in wetting ability, emulsifying power and in lowering of surface tension. The sodium phosphonooleate, being a poor foamer, could be used for machine laundry washing, dish washing and cosmetics. IICT Communication No. 2272.