Synthesis of a t-α-Hydroxy Oxime and its Synergistic Behavior with Versatic 10

The aliphatic α-hydroxyoxime LIX® 63 contains a secondary hydroxyl group that is susceptible to oxidation. In the present work, an alternative oxidation-resistant α-hydroxyoxime containing a tertiary hydroxyl group, namely (1-hydroxycyclohexyl)-phenyl ketone oxime (“phenyl oxime”), has been synthesized and characterized. Combining phenyl oxime with Versatic 10 results in synergistic metal extraction behavior. The ability of this ligand to withstand oxidation is demonstrated. Other benefits are also evident, including its existing wholly in the active anti isomeric form and exhibiting fast nickel kinetics in the synergistic system. Phenyl oxime readily undergoes aqueous acid-catalyzed hydrolysis and so is not commercially practical. Addition of carbon side-chains could help to overcome this.