SYNTHESIS OF DOCOSANOIC AND TETRACOSANOIC ACID FROM ALCOHOLS USING A TASK-SPECIFIC IONIC LIQUID CATALYST

Catalytic batch oxidation of docosanol to docosanoic acid and tetracosanol to tetracosanoic acid was performed using hydrogen peroxide as oxidant and a functionalized ionic liquid composed of an Aliquat (R) cation and a peroxotungstophosphate anion acting as catalyst. Conversion of 76% and selectivity of 60.2% were obtained after 6 hours for docosanol oxidation at optimal operational conditions (temperature of 90 degrees C; total-H2O2/alcohol molar ratio = 3; alcohol/catalyst mass ratio = 300). In the case of tetracosanol oxidation 85% conversion and 68% selectivity were reached in the same time interval at optimal operational conditions (temperature of 90 degrees C; total-H2O2/alcohol molar ratio = 5; alcohol/final-catalyst mass ratio = 50). In both cases the oxidant and the catalyst were continuously added throughout the reaction time, thus enabling continuous reaction performance. The batch results obtained in this study confirm the technical feasibility of operating a process to produce both these high molecular acids from alcohols as renewable raw materials.