Yield: 89.37%

Reaction Conditions:

Stage #1:2,2,3,3,4,4,5,5-octafluoropentan-1-ol with sodium tungstate;tetrabutylammomium bromide;dihydrogen peroxide in water at 85 - 90; for 8 h;
Stage #2: with barium carbonate in water for 1 h;Catalytic behavior;Reagent/catalyst;

Steps:

1 Example 1
30% by weight 136 g (1.2 mol) of aq. hydrogen peroxide, 3.96 g (0.012 mol) of sodium tungstate and 3.87 g (0.012 mol) of tetrabutylammonium bromide were placed in a flask equipped with a magnetic stirrer, reflux condenser, constant-pressure addition funnel, oil bath (room temperature) and a thermometer, stirring in an oil bath at 35 ° C for about 30 minutes to sufficiently dissolve sodium tungstate and tetrabutylammonium bromide.
After the temperature was raised to 85 to 90 ° C, 116 g (0.5 mol) of the raw material octafluoropentanol was added dropwise, and the mixture was further stirred vigorously (500 r / min) for 8 hours. Then, the reaction solution was heated to boil, tested with starch potassium iodide paper until no blue color appears. Adding 2.37g of BaCO3 powder, stirring reaction 1h, after cooling, the solid precipitate was removed by filtration. The colorless filtrate was concentrated by distillation under reduced pressure to remove water, and then extracted three times with one third of the filtrate volume of ether each time, the organic phases were combined, drying with anhydrous Na2SO4.
The desiccant was removed by filtration, after the filtrate was subjected to atmospheric distillation to separate the solvent and the raw materials, that is, the desired product, the boiling point of 157 ~ 158 deg. C (literature value of 158.8 deg. C), infrared detection at 1692cm-1 has a strong absorption band, acid-base titration with the national professional standards ZB / TG17003-86, the yield of octafluoropentanoic acid was 89.37%.

References:

Zhonghao Chenguang Research Institute of Chemical Industry;Luo, Yuanjun;Lv, Taiyong;Liu, Bo;Zhang, Ming;Zhang, Jianxin CN104355987, 2016, B Location in patent:Paragraph 0030; 0031; 0032; 0033