SU368232A1 - Method for isolating cyclohexyl hydrogen peroxide - Google Patents

Description

one

This invention relates to methods for isolating unstable hydroperoxides, a panrimer of cyclohexyl hydroperoxide, from oxidates.

There is a known method for isolating cyclohexyl hydroperoxide from its solution in cyclohexane by treating with 10% sodium carbonate solution to remove acids, neutralizing, adding at 6 ° C and stirring 40% sodium hydroxide solution in 100% excess to precipitate its sodium salt , filtering, dissolving the salt in water, treating the aqueous solution with carbon dioxide, distilling traces of water and hydrocarbon from crude lerekis oil at 0.1 mm Hg. Art. and subsequent distillation under a pressure of 10 mm Hg. Art., dissolving in cyclohexane and repeating the isolation operation. The yield of the target product is 38.3%, the degree of purity is 97.7%. The disadvantages of the process are the low yield of cyclohexyl hydroperoxide and the multistage process.

In order to increase the yield and purity of the target product of the proposed method, an aqueous solution of the sodium salt of cyclohexyl hydroperoxide is treated with an inorganic salt, for example sodium chloride, and an organic solvent that is not miscible with water, for example cyclohexane, before being treated with carbon dioxide. Then the same solvent is added, neutralized with acid, and the solvent is distilled off with a pressure of 10-10 mm Hg. Art. All operations are carried out at a temperature of about -10 ° C. Example 1. In a 2 l flask, load 1 l of a neutralized solution of oxidized cyclohexane with a hydroperoxide content of 1.81% and place it in an ice bath to cool the solution to 6 ° C. Then for 30 minutes with vigorous stirring, 34 g of a 40% NaOn solution are added dropwise. For a more complete precipitation of the sodium salt of cyclohexyl hydroperoxide, the solution is kept for 12 hours at -5 ° C, after which the precipitate is filtered through glass fiber,

washed on the filter with cooled cyclohexane and dissolved in ice water.

To remove organic impurities, the solution is saturated with sodium chloride and washed with cyclohexane (ml). Next, 350 ml of cooled cyclohexane was added to the aqueous solution and carbon dioxide was passed in over 45 minutes. This gives 335 ml of a solution containing 4.55% cyclohexyl hydroperoxide. Hydroperoxide yield

84.4% of the loaded. As an impurity, 0.040% (0.88% of hydroperoxide) of cyclohexanone is present (according to IR spectroscopy). Example 2. The solution obtained in example 1 is concentrated by distilling off the solvent 3 under a vacuum of a water-jet pump at room temperature. The concentrate is distilled at a bath temperature of 40-42 ° C, in pairs of 29-31 ° C. 8.4 g of hydroperoxide are obtained. The yield (based on the baseline) is 60.5%, n | f 1.4630. The product contains (in%): 99-100 hydroperoxide (determined by iodometric method), and as impurities 0.3-0.5 cyclohexanone (according to IR spectroscopy) and 1.3-1.5 cyclohexanol (determined chromatographically). Subject of the Invention Cyclohexyl hydroperoxide isolation method from its solution in cyclohexane by treating 36 82:32 4 with subsequent treatment with a solution of soda, alkali, subsequent filtration of the solution, processing the resulting sodium cyclohexyl hydroperoxide precipitate with water, carbon dioxide, an organic solvent, for example cyclohexane, followed by separation of the target product by known techniques, characterized in that, in order to increase the yield and degree of purity of the target product, an aqueous solution of sodium salt cyclohexyl hydroperoxide P with carbon dioxide treatment is treated with an inorganic salt, for example sodium chloride, and an organic solvent, for example cyclohexane.