DE952801C - Process for the liberation of technical products containing small amounts of acetylene alcohol as admixture from these admixtures - Google Patents

Description

Process for the liberation of technical, small amounts of acetylene alcohols 1.101 1 als'Beimengung-containing products from these admixtures Technical products, which by. Conversion of acetylene alcohols were obtained, e.g. B. butenols, butenediols, .butanediols or butyrolaatones often contain more or less large amounts of these acetylene alcohols as admixtures, which have hitherto been difficult to separate but can significantly interfere with further processing.

It has now been found that technical, small amounts of acetylene alcohols products containing as admixtures, in particular saturated or olefinic double bonds containing alcohols or lactones, in a simple manner from. free these admixtures can. if a mercury salt is applied to these products in aqueous-acidic solution can act, the mixtures after hydration of the acetylene alcohols warmed up to higher temperatures, sometimes in alkaline medium, for some time the hydration products of the acetylene alcohols condensed to form higher molecular weight products are, and then distilled.

One proceeds expediently in such a way that mar. the aqueous solution this. technical Product to be freed from added acetylene alcohol, small quantities Mercury sulfate or acetate and, mineral acid, e.g. B. sulfuric acid added. the the most favorable amounts of mercury salts and temperatures for hydration are different from case to case and let themselves through Preliminary tests easily determine. In general, about 1 to 10% mercury sulphate is sufficient, calculated on acetylene alcohol. If the resulting keto alcohol is easily oxidizable, so it reduces the mercury salt more or less rapidly, especially when it is warm to metallic mercury before the acetylene alcohol is fully hydrated. It is therefore often advantageous not to add the mercury salt all at once, but rather in portions admit it.

The progress of hydration can. z. B. by analytical determination of the keto alcohol produced in each case. Once no acetylene alcohol is more present, the reaction mixture,. expedient after removal of the Mercury and, after the addition of alkali, up to a p11 value of about io, a few Warmed up time, e.g. B. at boiling temperature. The keto alcohols, as far as they are have not already been oxidized in the course of the previous treatment and or: or have converted into higher molecular weight products; completely in non-volatile, higher molecular weight Converted condensation products.

The acetylene alcohols are then completely freed by distillation Products won. The procedure. is suitable e.g. B. to remove unreacted Acetylene alcohols from technical olefin or saturated alcohols that are used in the obtained catalytic hydrogenation of alkynylation products of aldehydes and ketones especially for the removal of butyne- (2) -diol- (1, 4) from technical anbutanediol = (i, 4) or from technical butene - (: 2) -diol- (i, 4), as is the case with partial hydrogenation from butyne- (2) -diol- (i, 4); also for the removal of hexyne- (3) -di0l- (2.5) from technical hexen @ - (3) -diol- (2,5), from propargyl alcohol from technical allyl alcohol or of butyne- (i) -01- (3) from technical-grade butene- (i) -o1- (3). It works on everyone Apply mixtures containing acetylene alcohols, regardless of whether they are in addition to the latter saturated or unsaturated compounds, or any of these types.

It can be carried out batchwise or continuously.

It is known from German patents 594 083 and 7:20 IOS to hydrate practically pure vinyl acetylene with the aid of mercury salts in aqueous acidic solution to give methyl vinyl ketone or butanol (i) -one - (3), and it is in German Patent specification 748 289 shows that this hydration of vinyl acetylene initially produces butanol- (i) -On- (3) and 3,3'-diketobutyl ethers, which can be converted particularly advantageously into methyl vinyl ketone by distilling the slightly alkaline reaction mixture, while strong alkalis or hot acids have a resinifying effect on the hydration products.

From these known facts. was not to "deduce that technical, Products which do not contain any acetylene groups and which only contain small amounts Acetylene alcohols (but no vinylacetylene) contained as an admixture, by treatment practically completely free from these admixtures in the manner described above can. It was not foreseeable that one would use the acetylene alcohols, which were only in small amounts Amounts added to the technical products containing no acetylene groups are able to hydrate with the help of mercury salts without affecting these products can and that the hydration products, again without impairing the other products, even without the addition of alkali or acid, to non-volatile substances can condense, so that they remain quantitatively in the subsequent distillation.

The parts mentioned in the examples are parts by weight.

Example s In 465o parts of an aqueous butenediol solution, in addition to 1q. 35 parts of butene- (2) -diol- (i, 4), 45 parts of butyne- (2) -diol- (i, 4) and 2o parts Contains butane, diol (i, 4), 2.3 parts of mercuric sulfate are dissolved. While stirring main add 9 parts of concentrated sulfuric acid and stir initially for 4 hours. at Ordinary temperature, then 2 hours at 40 ° and finally 1 hour at 100 °. The reaction solution is then brought to the p11 value with alkali and heated 15 minutes to simmer. After cooling, they are separated. from the separated mercury, the water is distilled off and the residue is distilled under reduced pressure. 1440 parts of a butynediol-free distillate are obtained which, in addition to butene- (2) -dior (i, 4) only contains 1,411 / o butanediol- (i, 4).

EXAMPLES In a solution which, in 233o parts of water, contains 95o parts of butanediol (i, 4) and So parts of butyne- (2) -diol- (1, 4) contains. 3 parts of mercury sulfate dissolved, whereupon 29 parts of concentrated sulfuric acid are added with stirring. The solution is initially stirred for 3 hours at 25 ° and 3 hours at 40 °. Thereafter it is brought to pH io by adding sodium hydroxide solution and 1 / z hour stirred at 100 °. After cooling down, the precipitated mercury is separated, then the water and finally the butanediol distilled off under reduced pressure.

93o parts of butanediol (1.4) are obtained, which is also in its last Fraction does not contain a trace of butyne- (2) -diol- (i, 4).

Example 3 8 parts of mercury sulfate are dissolved in a solution which, in addition to 1440 parts of butene- (i) -0l- (3), also contains 8 parts of butyne- (i) -0l- (3) and 35o parts of water. The mixture M: - t 27 parts of concentrated sulfuric acid is acidified, heated to 70 to 75 ° for 5 hours and then allowed to cool. Then the precipitated mercury is separated off and the solution is brought to the with alkali lye while stirring. p31 value 6 and distilled. 195o parts of a 70% aqueous solution of butene- (i) -01- (3), which passes over between 86 and 890 and no longer contains butyne- (i) -01- (3), are obtained.

Example q.

To parts of mercuric sulfate and 20 parts of concentrated sulfuric acid are added with stirring to a solution consisting of 2680 parts of y-butyrorlactone, 1200 parts of water and 12 parts of butyne- (2) diol- (1.4). The reaction mixture is stirred at ordinary temperature for 4 hours, at 40 'for 2 hours and finally at 1000 for 1 hour. Customary work-up by distillation gives 261o parts of γ-butyrolactone, the last fractions of which are free from butyne- (2) -diol- (1.4).

Example s To a solution from. i5oo Share butene- (2) -dial- (z, 4) and 45 parts of butyne- (2) -diol- (i, 4) in 750 parts of water become 5 parts of mercuric sulfate and. 5 parts concentrated sulfuric acid added. The mixture is heated i Hour and reflux to the boil, continuously passing a gentle stream of air through it the reaction mixture passes through it.

After cooling, you work up as usual and get in the distillation 146o parts of butene- (2) -diol- (z, 4), which no longer contains butyne- (2) -diol = (i, 4).

Claims (1)

PATENT CLAIM: Process for the liberation of technical, small amounts of acetylene alcohols as admixtures containing products, in particular saturated or olefinic alcohols or lactones, from these admixtures, characterized in that a mercury salt is allowed to act on these products in aqueous-acidic solution, after the hydration of the acetylene alcohols has ended, the mixtures are heated to higher temperatures for some time, expediently in an alkaline medium, until. the hydration products of the acetylene alcohols are condensed to form higher molecular weight products; and then distilled. Considered publications: German Patent Specifications Nos. 594 o83, 720 1o8, 748: 289.