DE2228333C3 - Process for the preparation of optionally substituted 2-butyn-4ols - Google Patents

Description

15th

20th

(Π)

have the meaning given above in which R ¹ and R ^2, smaller in the presence of an alkali metal hydroxide, alkali metal alcoholate, alkali metal amide or metallic lithium as an alkaline condensing agent in a practically water-immiscible solvent having a dielectric constant than 10, at temperatures of 0 to 50 ⁰ C. reacts with all or a gas mixture containing all

Z method according to claim 1, characterized in that that the solvent, which is practically immiscible with water, is added or polyhydric alcohols with 1 to 5 carbon atoms are added.

40 R ¹
O = CR ²

10

The preparation of 2-butyn-4-ols by reaction of aldehydes and ketones with propyne in the presence of alkaline condensing agents is known

Furthermore, from the German Offenlegungsschrift 55 843 known that propyne and allene can be mutated by using propyne and All-containing gas is brought into contact with a catalyst solution, which consists of a dtpolaren aprotic Solvent with a dielectric constant above 10 and a hydroxide or AUcoxide one Alkali metal * with an atomic number higher than 10

It has been found that 2-butyn-4-ols are used Formula I.

in which R ¹ and R ^{2 have} the meaning given above, in the presence of an alkali metal hydroxide, alkali metal alcoholate, alkali amide or metallic lithium as the alkaline condensation agent in a virtually water-immiscible solvent with a dielectric constant of less than 10 at temperatures from 0 to 50 ^° C. reacts with all or a gas mixture containing all

It was surprising that all were converted to 2-butyn-4-ols under the reaction conditions mentioned can be, since it is known on the one hand that for the mutual conversion of propyne and allene according to the German Offenlegungsschrift 19 55 843 the presence quite specific aprottich solvent is required and there on the other hand in the German Offenlegungsschrift 16 68 399 states that all of them are self-contained when treated with a dispersion of Sodium or lithium containing sodium behaves relatively inertly while propyne in the corresponding Propynylalkali metal compound is transferred. Furthermore, in the last-mentioned patent application stated that pure metallic lithium does not react even with propyne under the reaction conditions

For the conversion to 2-butyn-4-ols can be pure All to be used. However, this is used with particular advantage in the case of the thermal Cleavage of saturated hydrocarbons resulting mixture of allene and propyne, which only by very expensive distillation processes would have to be separated into allene and propyne. An extensive cleaning of the Allen propene mixture is not required because it is without Disadvantages also such gas mixtures can be used according to the invention, which in addition to allene and propyne contain other hydrocarbons, olefins or diolefins.

Compounds of the formula II come as aldehydes or ketones

R ¹
CR ²

R ¹

GHj-C = CC =
OH

in which R ¹ and R ^{2 represent} hydrogen, a saturated or unsaturated, branched or unbranched aliphatic hydrocarbon radical with 1 to 20, preferably 2 to 13 carbon atoms, a cycloaliphatic radical in which R ¹ and R ² each represent hydrogen, a saturated or unsaturated one , branched or unbranched aliphatic hydrocarbon radical with 1 to 20 carbon atoms, a cycloaliphatic hydrocarbon radical with 5 or 6 carbon atoms in the ring or a phenyl radical, or R ¹ and R ² together represent an alkylene radical with 4 to 6 carbon atoms, in μ Consideration Of particular interest are aldehydes 0) or ketones in which R ^{1 represents} hydrogen or a saturated hydrocarbon radical with 1 to 4 carbon atoms and R ^{2 has} the meaning given above for R ¹ and R ^2. Examples include: acetaldehyde, propionaldehyde , Isobutyraldehyde, citronellal, acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-methylhepten-1-one-6,2-methylhepten-2-one-6, geranyl acetone or hexahydro farnesylacetone.

The hydroxides, alcoholates and amides of sodium and potassium are particularly suitable as basic condensing agents. Metallic lithium can also be used. The process according to the invention is particularly advantageous with sodium or potassium alcoholates of primary or secondary alcohols having 4 to 8 carbon atoms, since these alcoholates can be obtained particularly economically from aqueous alkali lye by azeotropic distillation with the water-soluble alcohols only to a limited extent. The alkaline condensing agents are generally used in amounts of about 0.2 to 1.5 mol, preferably 0.3 to 1.0 mol per mol of aldehyde or ketone Quantities from about 0.2 to 1/2 moles of condensing agent per mole of aldehyde or ketone.

As a practically immiscible solvent with an X? ^; Electricity constants less than 10 are aliphatic or aromatic hydrocarbons, such as toluene, xylene, diacyl ethers such as diethyl ether, cyclic ethers such as tetrahydrofuran, hexamethylene oxide and dioxane and the acetals of lower aliphatic aldehydes, such as the diacetals of formaldehyde with aliphatic or acetaldehyde 4 C atoms into consideration Mixtures of the solvents mentioned can also be used. Solvents which may be mentioned in particular are: tetrahydrofuran and cyclic ethers of the tetrahydrofuran type and formaldehyde dibutyl acetal, formaldehyde diiso-butyl acetal, acetaldehyde diethyl acetal, acetaldehyde dibutyl acetal, acetaldehyde dibutyl acetal, ajetaldehyde diisobutyl acetal, dioxane. The organic solvents are generally used in amounts of about 3 to 15, preferably 5 to 10 parts by volume per part by volume of aldehyde or ketone.

The organic solvents must not contain any free hydroxyl groups or amino groups, because this reduces the effectiveness of the basic condensation agent.

On the other hand, it is when using condensation agents that are extremely difficult to dissolve or difficult to suspend - like the alkali hydroxides - it is advantageous to use small amounts of a hydroxyl group-containing To give compound as a solubilizer to the reaction mixture. Come as a solver especially mono- or polyhydric alcohols with 1 to 5 carbon atoms such as methanol, ethanol, isobutanol, ethylene glycol or glycerine into consideration. The solubilizers are generally used in amounts of 0.5 to 5 parts by volume per 100 parts by volume of the Solvent.

To carry out the process, a suspension of the alkaline condensate * in the selected solvent or solvent mixture is generally saturated with all or the all-containing gas mixture and then at temperatures of 0 to 50 ^s C, preferably 10 to 30 ° C, the aldehyde or the Ketone entered slowly while passing the gas or gas mixture through. The exhaust gases leaving the reaction mixture are collected and, if necessary, fed back into the process

When the aldehyde or ketone has been introduced, water is added to the reaction mixture and the phases that form are separated from one another. The organic phase is neutralized and then distilled. Any inorganic or organic acids that do not chemically change the reaction product can be used for neutralization. Examples include: formic acid, acetic acid, adipic acid and sulfuric acid. During the distillation of this organic phase, the amounts of unreacted allene or all-containing gas mixtures still dissolved in the solvent are recovered.
From the aqueous alkaline phase, Jurch

ίο React with primary or secondary alcohols with 4 to 8 carbon atoms and subsequent azeotropic distillation as an alkaline condensation agent usable alkali alcohols of these only to a limited extent water-soluble alcohols are obtained.

The reaction of the aldehyde or ketone with all or the allene-containing gas mixture can also be carried out under increased pressure. This procedure is advantageous when the solvent has only a low solubility for the allene or the allene-containing gas mixture, such as. B. with xylene or toluene. In most cases, however, there is a Working under increased pressure is not necessary.

With the help of the method according to the invention, it is possible to produce the butynols of the formula I in a simple and economical way from the as a by-product in the

Production of all or all of butadiene

containing gas mixtures and carbonyl compounds to manufacture.

The conversion of all to propyne and the

The reaction of propyne with the carbonyl compound takes place in the same reaction medium. The work-up of the reaction mixture after the reaction has taken place is extremely simple, since the solvents used are immiscible with the water added to the reaction mixture. This simple work-up option avoids wastewater and thus environmental problems. Furthermore, the solvents used according to the invention can be easily and completely separated from the aretylene alcohols formed, whereby very pure acetylene alcohols are obtained, which is not the case with solvents such as dimethyl sulfoxide and N-methylpyrrolidone, for example
The butynols of the formula I produced have found interest as intermediates for organic syntheses, as sleeping pills and sedatives, and as fragrances. In particular, the 2,6-dimethyl-2-nonene produced from 2-methylhepten-2-one-6 or 2-methylhepten-1-one-6 with all or all-containing gases

50? -In-6-ol and 2,6-dimethyl-1-nonen-7-yn-6-ol show good fragrance properties.

The parts mentioned in the following examples are parts by weight.

Example t

The suspension of 112 parts of potassium isobutylate in 67 Parts of xylene are distributed in 1600 parts of tetrahydrofuran under tubes, and the suspension obtained Saturated with pure allene for one hour at temperatures of about 25 ° C. There are about 150 parts All solved

Over the course of 4 hours, 252 parts of 2-methyl-1-hepten-6-one are introduced while all of them are passed through at temperatures from 25 to 30 ^{° C.} 24 parts of exhaust gas are collected in a freezer. The exhaust gas has the following composition: 84% propyne and 16% allene.

After entering the ketone, 100 Parts of water are added to the reaction mixture. 120 parts of an aqueous 43% strength potassium hydroxide solution are formed can be reused to produce potassium isobutylate.

The organic phase formed is neutralized by adding 2 parts of formic acid and then distilled. During this distillation, the unreacted Allen-Propyne-Gemisca, dissolved in the solvent, is collected. 276 parts of 2,6-dimethyl-l-nonen-7-yn-6-ol with a boiling point of b.p. ₈ = M ⁰ C and 31 parts of unreacted 2-methyl-lhepten-6-one are obtained. The yield is 94.5% of theory, based on converted 2-methyl-1-hepten-6-one.

Example 2

A gas mixture is introduced into the suspension of 112 parts of potassium isobutylate in 67 parts of xylene and 1600 parts of tetrahydrofuran at 20 ^° C. which, in addition to other hydrocarbons, olefins and butadiene, contains 44% allene and 22% propyne enter 252 parts of 2-methyl-2-hepten-6-one with further introduction of the gas mixture. The introduction is ended in 3 hours. The reaction temperature is kept at 20 ° C. during the introduction.

The reaction mixture is then mixed with 100 parts of water, the aqueous potassium hydroxide solution formed separated, the organic phase neutralized by adding 1 part of sulfuric acid and then dertilled. 268 parts of 2,6-dimethyl-2-nonen-7-η-6-ol are obtained with a boiling point Κρ «= 65 to 66 ° C and 22 "i parts of unreacted 2-methyl-2-hepten-6-one. The yield is 88.5% of theory, based on 2-methyl-2-hepten-6-one.

Example 3

ίο Pure allene is introduced into the mixture of 7 parts of lithium chips and 500 parts of tetrahydrofuran with stirring. The temperature of the mixture initially rises to about 45 ° C., but then falls again. With the simultaneous introduction of further allene, 126 parts of 2-methyl-2-hepten-6-one are introduced into the mixture at 20 to 30 ^{° C. in the course of 4-8 hours.} A total of 120 parts of allene are passed in. The reaction mixture is mixed with 20 parts of water. The separated organic phase is neutralized and distilled. 138 parts of 2,6-dimethyl-2 - are obtained in the distillation. jjnen-7-yn-6-ol with a boiling point b.p. ₈ = 97 ° C and a refractive index π = 1.4685 and practically no unreacted 2-methyl-2-hepten-6-one. The yield of 2,6-dimethyl-2-nonene-7-yn-6-oI is 83% of theory.

The 80 parts of the gas mixture recovered in the distillation in a deep-freeze receiver exist 60% from all, 7% from propyne and 33% from propylene.

Claims (1)

Patent claims: 1. A process for the preparation of optionally substituted 2-butro-4-ols of the formula I. R ¹ CH ₃ —C = C — CR ² 0) OH in which R 'and R ^{2 represent} hydrogen, a saturated or unsaturated, branched or unbranched aliphatic hydrocarbon radical with 1 to 20 carbon atoms, a cycloaliphatic hydrocarbon radical with 5 or 6 carbon atoms in the ring or a phenyl radical, or R ¹ and R ^z together denote an alkylene radical with 4 to 6 carbon atoms, characterized in that an aldehyde or a ketone of the formula Π R ¹
O = CR ² Hydrocarbon radical with 5 or 6 carbon atoms in the ring or a pbenyl radical, or R 'and R ² together represent an alkylene radical with 4 to 6 carbon atoms, can be prepared in a very advantageous manner if an aldehyde or a ketone of the formula II