DE931226C - Process for the preparation of 3,3-di- (chloromethyl) -cyclooxabutane - Google Patents

Description

Process for the production of 3,3-di- (chloromethyl) -cyclooxabutane By reaction of pentaerythritol trichlorohydrin with alkali hydroxide, preferably sodium hydroxide or potassium hydroxide, the 3,3-di- (oh'lormet 'is formed with elimination of hydrogen chloride) hyl) -. cyclooxabutane. As is bel: annt from: the literature, the alkali metal hydroxides are used here in solid form or in alcoholic solution [Fecht, reports of the German Chemical Society, 40, pp. 3888 to 3889 (1907); Proc. Acad. Sci. Amsterdam, 42, pp. 79o to 797 (1939)].

When using alkali hydroxides in solid form, the following occur Next up: The alkali hydroxide cakes and coats itself with one Crust of alkali chloride. This increases the response time. It kicks also resinification of the one. In technical syntheses, the handling of solid powdered caustic soda uncomfortable. If, on the other hand, you work with aqueous alkali, hydroxide solutions, so the reaction mixture is in@homoge.n, and the water partially decomposes what has been formed Oxabutane. This significantly reduces the yield.

Even when using an alcoholic solution of alkali metal hydroxides There are disadvantages because by-products are formed and part of the resulting Oxabutane is decomposed.

It has now been found that the production of 3.3-di- (chloromethya) -cyclooxabutane from pentaerythritol tri, chlorydrin or pentaerythritol trichlorohydric monoacetate can be carried out with good success with aqueous alkali hydroxide solutions, if you use an excess of an aqueous Alka # 1, i'hydroxydlösunig and works in the presence of an inert organic solvent at such temperatures, in which the existing and the resulting water by azeotropic distillation with the solvent continuously out of the reaction mixture. Will get removed. Using from Pentaeryt'hrittric'hIo @ hydrinmonoacetat you have to Add correspondingly more alkali, hydroxide, to remove the acetic acid that is released to tie.

It is advantageous to proceed in such a way that pentaerythritol triehlorohydrin is used in an inert, water-immiscible organic solvent, e.g. B. Benzene ', Toluene, etc., dissolves at low boiling temperature, with mechanical stirring the calculated Amount of aqueous alkali hydroxide solution slowly drips in and the water azeotropes with the organic solvent. distilled off. After separating the water can the solvent can be fed back into the reaction mixture.

It has also been shown that the excess of alkali metal hydroxide must not be too small in order to achieve good yields. It is advantageous to work with such amounts that at least 1.5 mol of alkali metal hydroxide is used for every one pentaerythritol trichloroacetate, or at least 3 mol of alkali metal hydroxide is used for one mol of pentaerythritol tric'hifor'hyd'rin monoacetate. Since: de implementation with the trichlorohydrin according to the equation If small amounts of alkali hydroxide are present, the trichlorohydrin is formed back again. In order to facilitate the removal of the water, it is therefore also advantageous to use highly concentrated alkali hydroxide solutions, e.g. B. with 50 '/ aigen solutions to work.

Surprisingly, it has been shown that when using Higher yields of potassium hydroxide were obtained than when using sodium hydroxide. Reasons for this different behavior have not yet been determined.

The procedure takes a certain amount of time. The aqueous alkali hydroxide solution is added dropwise as slowly as possible into the boiling solution of the pentaerythritol trichlorohydrin and. distilled so long with reflux of the organic solvent, until none Separates more water from the distillate. The resulting alkali chloride or the Mixture of Al'kal'ichloridl and APcalnacetat at. Use of, pentaerythritol trichlorihydrin.monoacetat The almost anhydrous reaction mixture can be used as starting material Separate the filtration quantitatively.

The reaction mixture thus obtained is in a known manner "z. B. by Desti'l'lation over small.: Amounts of solid alkali hydroxide, worked up.

The 3, 3-di- (chloromethyl), cyclooxabutane (F. = 18 '; Kps = 63 to 67'; ff o = 1.4858) obtained in this way is a valuable starting material for organic syntheses, e.g. B. for the production of plastics.

Example i 191.5 g of pentaerythritol trichlorohydrin (once) are dissolved in 750 cc of boiling benzene, whereupon a solution of 84 g of potassium hydroxide (1.5 mol) in 84 cc of water is added dropwise with mechanical stirring. The azeotropically passing benzene-water mixture is separated in a water separator, the benzene flowing back into the reaction vessel. The theoretically expected amount of water (10.2 ccm) is separated after about 4 hours. It is allowed to cool and the precipitated potassium chloride is filtered off with suction. The filtrate is mixed with 3 to 5 potassium hydroxide solution and freed from benzene by distillation under normal pressure. The residue is fractionated under reduced pressure. The 3,3-di- (chilomethyl) -cyclooxabutane .siedet at 6 mm between 63 and 67 °. Yield of 3,3-di- (chformeihyl) -cyclooxabutane: 132 g = 88% of theory, based on pentaerythritol tride-marhydrin.

Example. z 233.5 g P.aentaerythritol trichlorohydrin monoacetate (1 mol) are dissolved in 600 cc of benzene. A solution of is added dropwise at the boiling point Slowly put 168 g of potassium hydroxide (3 MQl) in 168 ccm of water and proceed as below i specified. The expected amount of water (2o6 ccm) is deposited after about 7 hours. It is worked up as described and i2gg of 3,3-di- (chloromethyl) -cycloaxabutane is obtained = 83% of theory, based on pentaerythritol trichlorohydrin monoacetate.

Claims (3)

PATENT CLAIMS: i. Process for the preparation of 3,3-di- (chilomethyl) -cyclooxabutane by reacting pentaerythritol trichloi'hydrin or pentaerythritol trichlorohydrin monoacetate with aqueous alkali hydroxide solutions, characterized in that there is an excess used in an aqueous Alkallühy.droxydlösung and in the presence of an inert organic solvent works at temperatures at which the existing and. the resulting water by azeotropic distillation with the solvent running is removed from the reaction mixture. 2. The method according to claim i, characterized in that d: one ate per MöT pentaerythritol trichlorohydrin at least 1.5 mol alkali hydroxide or at least 3 Mdl Afkal'ihydroxydi per Mod pentaerythritol trichlorohydrin monoacetate used. 3. The method according to claim i or 2, characterized in that: that one used as Al'kali'hydroxyd Kaliu.mhydroxyd,