LIGNOCERIC ACID synthesis

Yield:557-59-5 78.1%

Reaction Conditions:

with dihydrogen peroxide;3C₇H₁₈N⁽¹⁺⁾*O₂₄PW₄^(3-) in water at 90; for 8 h;

Steps:

2
Example 2Oxidation of the Raw Material300 g of a raw material comprising 80% by weight of lignoceric alcohol and 20% of other aliphatic alcohols, mainly docosanol and hexacosanol (Alchemist International Ltd., Hong Kong) was loaded into a 2 L jacketed glass reactor Oka Eurostar) provided with a variable speed stirrer, a jacket to circulate heating fluid (Therminol 66 thermal oil) and a reflux condenser. The temperature of the heating fluid was 95° C., which kept the reactor temperature at 90° C. during the reaction. Once the raw material melted and reached 90° C., 6 g of the catalyst prepared as described in Example 1 and 72 mL of 50% by weight of hydrogen peroxide were added to the melted mixture to start the oxidation reaction. The reacting mixture was stirred at 200 rpm by the reactor propeller. After two reaction hours, an additional 72 ml of 50% by weight of hydrogen peroxide were added, repeating the addition of 72 mL 50% by weight hydrogen peroxide after six reaction hours. After eight reaction hours, stirring was stopped and the aqueous and organic phases were left to separate. A sample was taken from the organic phase for analysis, which indicated a conversion yield of 78.1% from lignoceric alcohol to lignoceric acid and a total lignoceric alcohol conversion of 93.4%, where the yield is calculated as the mass percentage of lignoceric alcohol oxidized to lignoceric acid and the conversion is calculated as the mass percentage of total lignoceric alcohol transformed (by oxidation or another reaction).Sample AnalysisLignoceric alcohol and lignoceric acid were determined using an HP 6890 gas chromatographer with autosampler, provided with a HP-5 column (30 m×0.25 mm of diameter×0.25 μm) and a flame ionization detector operating in split mode (30:1). The injector temperature was set at 300° C. and the detector temperature was set at 320° C. The initial temperature of the column was 160° C. and was increased at a rate of 5° C./min, and keeping the isotherm for 10 minutes. The carrier gas was helium with constant flow (1 mL/min).Derivatization of Samples for AnalysisBetween 400 and 500 mg of sample are weighed in a scintillation vial with 20 to 30 mg of cholesterol as an internal standard. Subsequently, 15 mL of chloroform were added and the mixture was vortexed or sonicated if necessary to dissolve the components. 500 μL were transferred to a chromatography vial and evaporated under nitrogen. Then, 300 μL of sylanizing reactant (Bis (trimethyl) silyl trifluoroacetamide) and 400 μL of pyridine were added. The vial was closed and heated for 15 minutes, stirred again and 1.0 μL was injected into the chromatograph.From the chromatographic report, peaks of lignoceric acid and lignoceric alcohol were identified by comparison to the retention times of corresponding standards. The lignoceric alcohol and lignoceric acid standards were purchased from Sigma (L 3507 and L 6641 respectively) with purities of 99% or more and weight percentages were calculated for each species.

References:

HARTING S.A.;PONTIFICIA UNIVERSIDAD CATOLICA DE VALPARAISO US2012/130100, 2012, A1 Location in patent:Page/Page column 3-4

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