DE1015782B - Process for the production of epoxies - Google Patents

Description

Process for the production of epoxies For the production of epoxies of olefinic hydrocarbons with isolated double bonds by addition These hydrocarbons are converted by oxygen with organic peracids. This process, known as the Prileshajew reaction, produces predominantly aromatic substances Peracids, in particular benzoperacid, are used. The more accessible ones aliphatic peracids, especially peracetic acid, deliver among the same Conditions only poor yields of epoxides. In addition, glycols or Glycol monocarboxylic acid ester. In some cases, especially with hydrocarbons with more than one isolated double bond, resins are usually obtained.

It has now been found that one can use monofunctional and polyfunctional olefins with isolated double bonds with aliphatic peracids, especially peracetic acid, can be converted into epoxides in good yields by adding to the reaction mixture Adds buffer salts. The buffer salts can optionally also only be added to the reaction mixture be generated.

The effect achieved in this way is largely independent of the species any solvents used and surprisingly not the presence or absence of water in the reaction mixture.

Mono- and polyfunctional olefins, according to the invention in epoxies can be transferred, are z. B. pentene, isopentene, witches, isohexene, heptene, Isoheptene, octene, isooctene, diallyl, cyclohexene, cycloheptene, cyclooctene, 2,2-dicyclohexenyl propane, 2,2-dicyclohexenyl = butane, 2,2-dicyclohexenylpentane, 1,1-dicyclohexenylethane, 1,1-dicyclohexenyl-butane, dipentene, styrene, α-methylstyrene and stilbene.

Aliphatic peracids for the purposes of the invention are, for. B. performic acid, Peracetic acid, perpropionic acid, perbutyric acid and adipic diperic acid.

As a solvent, for. B. water, methylene chloride, chloroform, Carbon tetrachloride, ethers, benzene and toluene can be used.

Examples of buffer salts are: sodium, potassium, calcium, Magnesium formate, acetate, butyrate, disodium adipate, disodium phthalate and sodium dihydrogen phosphate.

In their place, sodium, potassium, calcium, Magnesium oxide, hydroxide, carbonate and bicarbonate are used, from which the corresponding buffer salts are formed in the reaction mixture.

The amount of buffer salts to be added depends on the pH, which occurs in the presence of water in the reaction mixture or after addition of water would adjust to the reaction mixture, and can be varied on a case-by-case basis easily determined by preliminary tests. The most favorable pA range is generally at about 4 to 6.5.

At a higher pH, undesirable secondary reactions are also excluded, but then the yields decrease as a result of the more and more coming to the fore Decomposition of the peracids.

It is a particular advantage of the procedure that in many cases the reaction temperature, within wide limits, has little influence on the Yield is. Thus, the reaction temperature can be between about -20 and -I-100 °, preferably lie between about 0 and 70 °.

Special precautionary measures are not necessary during processing, because even sensitive epoxies such. B. that of styrene or a-methylstyrene, which are quickly attacked by dilute acetic acid even in the cold, in the specified pH range are stable.

Example 1 After adding 50 g of anhydrous sodium acetate to a solution of 59 g (0.5 times) of α-methylstyrene in 100 cc of methylene chloride, 47 g of an 89.5% peracetic acid (0, 55 mol) are added dropwise. The temperature is then allowed to rise to about 30 ° and is kept at room temperature for a further 3 hours. Then it is extracted with water, neutralized with soda solution and dried over anhydrous potassium carbonate. 62 g of α-methylstyrene oxide are obtained at 60 to 62 ° / 6 mm Hg. Yield: 92.5% of theory. Analysis: C, Hio0 (molecular weight 134.17) Calculated .... C 80.56, H 7.51, O 11.93; found ..... C 80.95, H 7.28, 0 11.48. Without the addition of sodium acetate, under otherwise identical conditions, only an 18% yield of α-methylstyrene is obtained.

Example 2 'To a solution of 59 g (0.5 mol) of α-methylstyrene in 100 ccm of methylene chloride is left after the addition of 40 g of anhydrous sodium acetate and 20 g of anhydrous potassium carbonate at 0 ° within 2 hours 57 g of an 80.5% Add peracetic acid (0.6 1M1) dropwise. After a reaction time of 4 hours at room temperature it is shaken out with water, washed neutral with soda solution and dried over anhydrous Potassium carbonate. 57 g of α-methylstyrene oxide are obtained at 54 to 66 ° / 5 mm Hg. Yield: 85% of theory.

Example 3 After adding 110g of anhydrous sodium acetate at 25 °, 127 g of an 89.5% perbutyric acid (1, 1 11ol) are added dropwise. After standing for 10 hours at room temperature, it is extracted with water, washed neutral with soda solution and dried over anhydrous potassium carbonate. After distilling off the solvent, 96 g of isoheptene oxide with a boiling point of 112 ° to 120 ° are obtained. Yield: 84% of theory. Analysis: C7H140 (molecular weight 114.18) Calculated .... C 73.63, H 12.36, O 14.01; found ..... C 74.01, H 12.42, O 13.54. Without the addition of sodium acetate, the yield under otherwise identical conditions is over 49% of theory.

Example 4 After adding 60 g of anhydrous sodium acetate at 25 °, 52.5 g of an 80% peracetic acid (0, 55 mol) are added dropwise. After standing for 2 days at room temperature, it is extracted with water, washed neutral with soda solution and dried over anhydrous potassium carbonate. After the solvent has been distilled off, 56 g of 2,2- (dicyclohexenyl) propane dioxide are obtained at 140 to 155 ° / 1 mm Hg. Yield: 95% of theory. Analysis: C "H24 02 (molecular weight 236.34) Calculated .... C 76-22, H 10.24, O 13.54; found ..... C 76.43, H 10.15, O 13.41. Without the addition of sodium acetate, under otherwise identical conditions, an undistillable resin is obtained.

If only a quarter of the amount of sodium acetate given above is used, then, under otherwise identical conditions, the yield is 47% of theory.

Example 5 To a mixture of 102 g (0.5 mol) of 2,2-dicyclohexenylpropane, 200 cc of water and 109 g of anhydrous sodium acetate are left with vigorous stirring at 40 ° 110 g of an 85% strength peracetic acid (1.3 mol) are added dropwise. Then warmed up one another 2 hours at 60 ° until the peracetic acid is consumed. The aqueous layer is separated off, the organic layer is taken up with methylene chloride, with Sado solution Shaken neutral and dried over anhydrous potassium carbonate. After distilling off of the solvent is obtained at 138 to 155 "/ 1 mm Hg 96g of 2,2-dicyclohexenyl propanedioxide. Yield: 81% of theory.

Claims (2)

PATENT CLAIMS: 1. Process for the preparation of epoxides from olefinic hydrocarbons with isolated double bonds by reacting the hydrocarbons with aliphatic peracids, characterized in that buffer salts are added to the reaction mixture. 2. The method according to claim 1, characterized characterized in that the buffer salts are allowed to arise in the reaction mixture.