DE1150675B - Process for the production of cyclododecene with predominant content of cis-cyclododecene - Google Patents

Description

Process for the manufacture of predominantly content cyclododecene of cis-cyclododecene It is known that cis-cyclododecene can be obtained by partial hydrogenation of the difficult to access cyclododecine (Heiv. Chim. Acta, vol. 38, 1955, p. 1786).

It is also known to produce cyclododecene by using cyclododecatriene- (1,5,9) partially hydrogenated (German patent 1 130 804). According to this procedure, one obtains although in good yield an isomer mixture which, in addition to 5 to 100 / o cyclododecadiene- (1,5) and cyclododecane contains over 60 ovo trans isomer, but it does not succeed this process to produce cyclododecene with a predominant content of cis isomers or to isolate the cis isomer from the mixture. The still known methods for the production of cyclododecene, e.g. B. the elimination of hydrogen chloride from chlorocyclododecane (German Auslegeschrift 1103 325) or the Hofmann degradation of aminocyclododecane (Helv.

Chim. Acta, Vol. 38, 1955, p. 1786) also provide mixtures predominant content of trans-cyclododecene.

It has been found that cyclododecene is predominantly used on cis-cyclododecene can be produced if one cyclododecadiene- (1,5) is known per se Converted way into the previously not described monoepoxide, this in itself known Way isomerized to cyclododecenone and its semicarbazone in per se known Way heated with alkaline agents in the presence of diluents.

The cyclododecadiene (1,5) used as starting material is after the procedure of the German patent 1138764 obtained. The cyclododecadiene (1.5) is epoxidized in a manner known per se by this compound, which optionally in solvents such as ethyl acetate and acetone, can be dissolved, with a Solution of peracids, such as performic acid, peracetic acid or perbenzoic acid, or of hydrogen peroxide and organic acids or buffer solutions in single or multi-phase System implements. The reaction is generally carried out at room temperature, however, you can also at lower or higher temperatures, for example at 0 or 500 C work. In practice, only the monoepoxide is obtained and only a very small amount Amounts of diepoxy compound. The distilled 5,6-oxidocyclododecene (1) is then heated with stirring to 115 to 1250 C and then in amounts of 0.1 to 10 percent by weight, based on the epoxy used, one of the usual isomerization catalysts, z. B. halides, preferably magnesium iodide, are added. You give the catalyst at room temperature to the epoxy and then heated, the yields are low achieved.

The temperature in the reaction mixture rises to about 1600 C; after this Cooling is continued and then distilled in vacuo. Implementation of the cyclododecenone to the semicarbazone is carried out in a manner known per se by adding the Mixture of at least stoichiometric amounts of cyclododecenone and semicarbazide hydrochloride in the presence of potassium acetate in alcoholic, preferably aqueous-alcoholic Solution heated to boiling. After the solvent has been distilled off, the residue becomes treated with highly dilute acids, such as dilute hydrochloric acid, and separated off.

The raw semicarbazone or recrystallized from alcohol is mixed with alkaline agents heated in the presence of diluents. The reaction mixture obtained is diluted with water, neutralized and advantageously distilled with steam. The organic phase is separated off and the aqueous phase from the steam distillate Phase extracted, for example, with ether or cyclohexane. The separated organic Phases are combined and distilled.

Suitable alkaline agents for the decomposition of the semicarbazone in relation to cyclododecene, the alkali and alkaline earth alcoholates are more aliphatic and cycloaliphatic monohydric and dihydric alcohols such as methanol, ethanol, propanol, butanol, cyclohexanol and especially ethylene glycol, diethylene glycol, triethylene glycol and higher molecular weight Polyglycols, or monoglycol ethers, such as ethyl polyethylene glycol. The production the alcoholates take place in a well-known manner Way by reacting the alcohols with the alkali metals or the alkali or alkaline earth metal hydroxides. That with this one The water formed in the reaction is expediently distilled off before the semicarbazone is added. The alcoholates are in at least stoichiometric amounts, preferably in one Excess of 1 to 5 moles based on 1 mole of semicarbazone is used.

It was not to be expected that by the process of the invention Cyclododecene obtained would consist predominantly of the cis-isomer, since it was previously The rule was that cis double bonds are epoxidized faster than the trans double bonds (Journ. Am. Chem. Soc., Vol. 69, 1947, p. 1693).

Compounds with a preferred steric arrangement win for production of polymers increasing in importance. The compounds obtained are used as an additive to organometallic catalysts or used as solvents to the steric To direct the course of reactions, for example the polymerization of olefins.

Example In 150g (0.915 mol) of cyclododecadiene (1.5), the 920/0 des containing cis-trans and 8% of the trans-trans isomers are at room temperature within half an hour 210 g of a 33.1% solution of 0.99 mol of peracetic acid added dropwise in ethyl acetate.

After the evolution of gas has ceased, it is distilled. It will be at 0.3 Torr and 750 C 124 g of 5,6-oxidocyclododecene (1) were obtained. That corresponds to a yield from 76ovo the theory.

37 g (0.205 mol) of 5,6-oxidocyclododecene (1) are heated to 1200.degree. Then 1 g (2.7%) of MgJ2 etherate is added. With strong foaming, the The isomerization reaction starts immediately, the temperature in the reaction vessel increasing to 1600 C increases. After cooling, the mixture is at room temperature for another 3 hours stirred. At 0.1 Torr and 88 to 900 C, 33 g of cyclododecenone are obtained, correspondingly 89 per cent of theory.

A solution of 33 g of cyclododecenone (0.18 mol), 11 g of potassium acetate (0.20 mol) and 22 g of semicarbazide hydrochloride (0.20 mol) in 500 ml of ethanol and 110 ml of water is refluxed for 11 hours, then the alcohol distilled off, the residue was taken up with 300 ml of the above hydrochloric acid and filtered off with suction and dried. The yield is 33 g of cyclododecenone semicarbazone, that is 80% the theory. The semicarbazone melts after recrystallization from ethanol 203 by 2050 C.

43 g (0.77 mol) of potassium hydroxide are added to 160 ml of ethylene glycol and the water of reaction is distilled off from the solution under reduced pressure. to 26 g (0.109 mol) of cyclododecenone semicarbazone are added to this solution, and the mixture is heated to 1800 ° C. for 10 hours. Then with 1 1 water added, neutralized and the reaction mixture is distilled with steam. the The upper, oily layer of the distillate is separated off and the lower, aqueous layer three times shaken out with ether. The oil and the ethereal solution are combined, the Ether is distilled off and the residue is distilled in vacuo. Yield: 10 g Cyclododecene (= 55% of theory). Feces 2 68 to 700 C, n2D0 = 1.4868, D.24 ° = 0.8750. The cyclododecene consists of 790 per cent of the cis and 21 per cent of the trans isomer.

PATENT claims I: Process for the production of cyclododecene with predominant content of cis-cyclododecene, characterized in that one cyclododecadiene- (1,5) in a manner known per se with peracids or hydrogen peroxide in the presence of organic acids or buffer solutions at 0 to 500 C, optionally in the presence of solvents, converted into the monoepoxide, this in the way in the presence of halides, such as magnesium iodide, isomerized at 115 to 1600 C to cyclododecenone, that one first heats the epoxy and only then adds the catalyst, the cyclododecenone converted into semicarbazone in a manner known per se with semicarbazide hydrochloride and this in a manner known per se with alkaline agents in the presence of diluents heated.

Documents considered: German Auslegeschrift No. 1 103 325.

Claims (1)

Older patents considered: German Patent No. 1 130 804;