SU1176827A3 - Method of producing alpha,beta-non-saturated ketones - Google Patents

Abstract

METHOD OF OBTAINING oi, and-UNSATURATED KETONES of the general formula E-CH CH-C-CH3 O where R is an alkyl group having 2-5.7.9 carbon atoms, 2 (ethylthio) propyl; 1- (ethylthio) propyl; 2- (phenylthio propyl; 2-

Description

The invention relates to a method for producing y, p -} gene saturated ketones, which are used as intermediate products for the production of medicines and pesticides, in particular, 6-ethylthio-3-hepten-2-o is used for the production of herbicides ... , / 3 saturated ketones by condensation of aldehydes with α-acetone in the presence of piperidine-acetic acid, which serves as a catalyst • However, this method uses a large amount of expensive catalysts and a large excess amount of acetone „ In addition, when lightly dissociating aldehydes are used, such as 3-ethylthiobutanol, etc. ketones are obtained with a very low yield as a result of its decomposition. There is also known a method for the preparation of oC, / 3-unsaturated ketones by the interaction of aldehydes with a Beattig reagent, which is formed by taking on the action of monochloroacetone or monobromoacetone with triphenylphosphine 21. However, in this method, the Beattiz reagent is an expensive substance, and the purification of waste containing phosphines is difficult. The closest technical solution to the invention is a method for producing unsaturated ketones by reacting aldehydes with diketones at room temperature. The disadvantage of this method is the duration of the reaction (the reaction mixture is kept for about two days) and the low yield of the target ketones (55-60%). The aim of the invention is to increase the yield of the target product. I The goal has been achieved in that, according to the method for producing oi, fl-unsaturated ketones of the general formula R CH-C CH. II where R is an alkyl group having 2-5.7.9 carbon atoms, .- (ethylthio) propyl; 1- (ethylthio) propyl; 2- (phenylthio) propyl; 2- (4-methylphenylthio} propyl; 2- (4-chlorophenylthio) propyl; 2- (ethylsulfonic) propyl; 2- (4-methylphenylsulfonyl) propyl, by condensation of an aldehyde with a carbonyl-containing compound, an aldehyde of general formula R-CHO is used as an aldehyde where R - has the indicated meanings, and as the carbonyl-containing compound, sodium acetoacetic acid is used in the presence of a secondary amine selected from the group: N-apyl-n-alkylamine, pyrrolidine, piperidine, 3-methyl-pipridine, morpholine in a mixture of heterogeneous solvent forming a layer of oil and selected from the group: toluene, chloroform and water at, 30 ° C and at a volume ratio of toluene or chloroform to water, equal to 40:60. According to the proposed method oi, the unsaturated ketones of the synthesis are a 3-alkene- 2-ones having the general formula K — CH — CH — CH — CH 3 wherein R is an alkyl group containing 2-5.7, 9 carbon atoms, 2- (ethylthio) propyl, 1- (ethylthio) propyl; 2 - (Phenylthio) propyl; 2- (4-metsh1phenylthio) propyl; 2- (4-chlorophenylthio) propyl, 2- (ethylsulfonyl) propyl, and 2- (4-methylphenylsulfonyl) propyl. The alkyl aldehydes used as the raw material include the hydrogen atom in the i-position, and they are represented by the general formula and are all propionic aldehyde, n-butyraldehyde, n-valeraldehyde, n-nylon aldehyde, n-caprylic aldehyde, n-caprine aldehyde , 3- (ethylthio) butyl aldehyde; 2 (ethylthio) butyl aldehyde; 3- (phenylthio) butyl aldehyde; 3- (4-methylphenylthio) butylaldehyde; 3- (4-chlorophenylthio) butylaldehyde; 3- (ethyl sulfo 3

nyl) butyl aldehyde and 3- (4-methylphenium sulfonyl) butyl aldehyde.

Other starting materials used in this process are alkali metal salts of acetoacetic acid of the general formula

CHg-C-CHgCOO Na® (y) O

Acetoacetic acid metal salts are readily prepared in an aqueous solution by hydrolysis of diketone or acetoacetones using a single alkali, such as sodium alkali

The reaction between these aldehydes and alkali metal salts of acetoacetic acid proceeds in the presence of an aliphatic amine in a mixture of heterogeneous solvents that form a layer of oil and water, according to the following reaction scheme: К-СНО + СНзС CH2-COO®JK -

 f

- К-СН СН-ССНз + НСОз

about

and the result is the desired ketones and alkali metal bicarbonate salts

In this reaction, an amine selected from the group of aliphatic secondary amines is used as a catalyst, for example cyclic aliphatic amines, such as pyrrolidine, morpholine, .3-methylpiperidine, and N-alkyl-n-alkylamines, such as dimethylamine, diethylamine, di- n-propylamine, di-n-butylamine, N-methyl-n-butylamine, K-these butylamine, N-methyl-n-amylamine, N-methyl-n-hexylamine, N-methyl-n-heptamine, N-methyl-n -octylamine, N-ethyl-nlaurilamine, etc. Amines cause the selective action of aldehyde on the alkali metal salt of acetoacetic acid. However, it is undesirable to use aliphatic secondary amines, such as diisopropyl amine, dicyclohexylamine, due to spatial difficulty.

Said reaction is limited in a mixture of heterogeneous solvents, forming an oil layer and an aqueous layer. A layer of oil is obtained by using insoluble materials — or eaten.

68274

a water-soluble organic solvent, for example, chloro-chlorine hydrocarbons, such as chloroform, and aromatic hydrocarbons, 5 such as toluene.

According to the invention, the ketone (desired product) is prepared as follows.

More than 0.005 mol of amine per 10 1 mol of aldehyde, preferably

from 0.02 to 0.08 mol of amine per 1 mol of aldehyde, - which serves as a catalyst, is introduced into an aqueous solution containing from 1.0 to 5 1.5 mol of SOLO-alkaline metal acetoacetic acid, per 1 mol of aldehyde, preferably -from 1.1 to 1.3 mol of said salt per 1 mol of aldehyde, which is obtained as described above, and then the pH of the resulting solution is adjusted to 6.08, 0 by the addition of an inorganic acid, such as hydrochloric acid and other acids .

5 In the solution prepared in this way, containing an alkali metal salt of acetoacetic acid and a catalyst, 100-500 ml of organic solvent are added per 1 mole Q aldehyde.

The resulting mixture is then stirred for 2 to 7 hours under atmospheric conditions and at.

During this reaction, the pH is maintained at 6.08, 0 by adding dropwise an inorganic acid, such as hydrochloric acid and other acids.

 The conditions of this reaction vary slightly due to the type and amount of aldehydes, amines and organic solvents used. However, the reaction using a number of parameters outside the specified limits is desirable due to a decrease in the yield of the final ketone -.

Upon completion of this reaction, in the case of obtaining alkali metal bicarbonate crystals, these crystals are decomposed by introducing an inorganic acid, such as hydrochloric acid and other acids, and then formed: inorganic

5 compounds are dissolved in the aqueous layer. Next, the reaction mixture is divided into a layer of oil containing the desired ketone formed (desired; product) and an aqueous layer containing the resulting inorganic compound (through the use of a well-known method, such as filtration and others. Ketone- (desired product) is obtained by evaporation and subsequent distillation of the indicated separated layer of oil. According to the proposed method, the synthesized 0, j6 - unsaturated ketones are 3-tridecen2 o 3-undecene-2-one; 3-nonen-2- he; 3-ok ten-2-one | .Z-hepten-2-one; 3-hexen2-one; 6-ethylthio-3-hepten-2-one; 5-ethylthio-3-hepten-2-one; 6-phenylthio-3-hepten-2-one; 6- (4-methylphenylthio) -3-hepten-2-one; 6- (4 chlorophenylthio) -3-hepten-2-one; 6 ethylsulfonyl-3-hepten-2-one and 6- (4-methylphenylsulfonyl) -3-hepten-2-one. The yield of the desired product is 80% under mild reaction conditions, e.g. at atmospheric pressure and at room temperature, with the target tissue being easily separated from the reaction mixture. The invention is illustrated by the following examples. Example 1. Preparation of an aqueous solution of sodium acetoacetic acid, 0.39 mol of methylacetoacetate and 54.6 g of water are introduced into a 300 ml reactor and then 54., 6 g of a 30% sodium alkali aqueous solution are introduced into the reaction mixture. During the introduction of sodium alkali, the temperature is maintained below 35 ° C by means of a water bath. The mixture is podderisayut at 30-35 ° C for 6 hours with stirring, while the hydrolysis reaction proceeds. The pH of the reaction mixture is adjusted to 8.3 by the addition of concentrated hydrochloric acid, and the result is an aqueous solution of sodium acetoacetic acid. Preparation of α-3-unsaturated ke Into an aqueous solution of sodium acetoacetic acid obtained as indicated above, 0.0225 mol of di-n-butylamine is introduced and then the pH of the mixture is adjusted to 6.0 by the addition of concentrated hydrochloric acid. 60 ml of toluene and 3.0 mol of n-capraldehyde are introduced into the mixture and stirred for 4 hours, while maintaining the temperature. The volume ratio of toluene: water is 40:60. After completion of the reactions, concentrated hydrochloric acid was slowly added dropwise to the mixture in order to decompose the crystalline sodium bicarbonate. Then, from the reaction mixture, the oil layer and the AQUATIC layer are separated by decantation. The oil layer is concentrated and then distilled off in vacuo to obtain 51.8 g of a colorless oily product having a boiling point of 106-112 ° C at a pressure of 0.8 mm Hg. (torr and nj 0.4550). This oily product is identified by gas chromatography as 3-tridecen-2-one. The purity of the H-tridecen-2-one is 97.9% and the yield is 86.2%. Examples 2-16. These examples are carried out as in Example 1, but using other aldehydes, amines and other conditions (see table). The table presents the results, according to examples 1,2-16. Example 17. About 30 mol of methyl acetoacetate and 42.0 g of water were introduced into the reactor with a volume of 300 ml, then 42.0 g of 30% aqueous sodium hydroxide solution was added to this mixture. During the addition of sodium hydroxide, the temperature was kept below 35 ° C using a water bath with constant stirring. This mixture is kept at 30-35 ° C for 6 hours with stirring and the hydrolysis reaction is carried out. The pH of the reaction mixture was adjusted to 8.3 by adding concentrated hydrochloric acid, resulting in an aqueous solution of sodium and acetoacetic acid, to the latter 0.013 / 5 mol of di-n-butylamine was added, after which the pH of this mixture was adjusted to to 6.0 by addition of concentrated hydrochloric acid. 46 ml of toluene (and 0.23 mol of 3-ethylthiobutanal (3-ethyl thiobutylaldehyde) are added to this mixture, after which the mixture is stirred for 5 hours at 30-35 ° C, the pH is adjusted to 6.5 by adding concentrated salt Noah acid.

Thereafter, the organic solvent layer and the water layer are separated from the reaction mixture.

The product in the organic pa layer, the solvent is analyzed by gas chromatography.

The yield of 6-ethylthio-3-hepten-2-one is 83.1%.

Comparative Example 1 (reaction of a homogeneous solvent using di-n-butylamine as catalyst).

The aqueous solution of sodium and acetoacetic acid prepared in Example 17 is added with 0.0115, mol of di-n-butclamine, after which the pH of this mixture is adjusted to 6.0 by addition of concentrated hydrochloric acid. 75 ml of methanol and 0.23 mol of 3-ethylthiobutanol are added to this mixture, after which the mixture is stirred. For 5 hours at 30-35 ° G, the pH is adjusted to 6.5 by addition of concentrated hydrochloric acid. After completion of the reaction, the reaction mixture is extracted with 50 ml of toluene, and the organic solvent layer is analyzed by gas chromatography.

The yield of 6-ethylthio-3-hepten-2-one is 30.5%.

Example 2 (comparative), Reaction of a heterogeneous solvent using n-butylamine as catalyst. The procedure of Example 17 is repeated, except that n-butylamine is used here. The yield is 7.6%. Comparative example (reaction of a reterogenic solvent using tri-n-butylamine as catalyst).

The procedure presented in Example 17 is repeated, except that trine-butylamine is used here.

The yield is 4.9%. The above comparative. examples show that the yield of the product according to the proposed method increases significantly

Thus, the proposed method allows to increase the yield of target ketones from 60% by a known method to 85-96%,

Cxi

tf, cho

Claims (2)

METHOD FOR OBTAINING, li-UNSATURATED KETONS OF GENERAL FORMULA R-CH = CH-C-CH ₃ II ^J 0 where R is an alkyl group having 2-5.7.9 carbon atoms, 2 (ethylthio) propyl; 1- (ethylthio) propyl; 2- (phenylthio) propyl; 2- (4-methylphenylthio) propyl; 2- (4-chlorophenylthio) propyl; 2- (ethylsulfonyl) propyl; 2- (4methylphenylsulfonyl) propyl,. by condensation of the aldehyde with a carbonyl-containing compound, characterized in that, in order to increase the yield of the target product, an aldehyde of the general formula is used as the aldehyde R - CHO where R - has the indicated meanings, and the sodium salt of acetoacetic acid in the presence of S is used as a carbonyl-containing compound as a secondary amine catalyst selected from the group; N-alkyl-n-alkylamine, pyrrolidine, piperidine, 3-methyl-piperilin, morpholine, in a mixture of heterogeneous solvents forming a layer of oil and selected from the group: toluene, chloroform, and water at 30 ° C and with a volume ratio of toluene or chloroform to water equal to 40:60; SU "" 1176827>