SU854925A1 - Method of preparing beta-ketols - Google Patents

Description

(54) METHOD OF PREPARING / -KETOLS The invention relates to an improved method for producing p-keto .p which can be used to obtain pC glycols, ft-unsaturated ketones, alcohols, diene hydrocarbons, heterocyclic compounds. A known method of producing (-ketoles by reacting ketones with ketones in the presence of a compacting agent as a 1.4% aqueous solution of NaOH 1. This method is not universal, since it can be used to condense only non-branched, water-soluble ketones. Known a method for producing / 3-ketols by reacting ketone, magnesium and halogen ketone in an ether-ash-free medium 2. The disadvantage of this method is the use of halogen ketones (lacrimators), as well as the inaccessibility of some of them (for example, 1-bromo-3-methyl butane-2).The closest to the present invention is a method for producing p-ketols, in which halogen magnesium magnesium lilinates are used as a densifying agent to condense highly branched ketones with ketones (or aldehydes with ketones), resulting from the interaction of the Grign re and BTqpH4Horo reagent of a fatty-aromatic amine. organic solvent (ether) at a temperature of from -15 to -18 ° C for 3-4 hours, followed by decomposition of the resulting halogen-ketketol with water and removal of secondary fat aromatic amine. The secondary fatty aromatic amine which was formed as a result of the reaction was removed with a weak acid solution, and the target product was isolated using known methods 3. However, this method is characterized by an insufficiently high yield of the final product (does not exceed 50%), due to its partial decomposition during the separation of the secondary fatty-aromatic amine acid; insufficient purity of the final product due to partial dehydration, cleavage and tarification of f-ketols under the action of acids. The purpose of the invention is to increase the yield of fb-ketols.

The goal is achieved by the fact that the preparation of 5-ketols is carried out by reacting ketones with ketones in an absolute solvent at a temperature of from -15 to in the presence of Grignard reagent and a secondary aromatic, amine with decomposition of the resulting halomagnet with water, and a distinctive feature is

(iHjMg Л-6гНбКНС {бН5- -СгН5 (Мдэ) (1вН54-ЙНц f Pfd-CHiVBt-d-dHj-HMHUflk cf-dHz-ci-Ez

that the secondary fatty aromatic amine is removed from the reaction mass by extraction with an absolute solvent selected from the group: hexane, carbon tetrachloride or myochloralkyl of the general formula H-C1, where either CjH or sec-CH is before the decomposition stage of the halomagnetite, the process proceeds as follows :

.

OMqa 0 CtHftiHCfHS

cJ- (lHr i-iz- HzOj omdz o

SNZ e-S-Kg

Mg (OH) a

II o

he

h

In this case, the secondary fatty aromatic amine, which is liberated during this reaction, is extracted with a solvent.

In the known method, the hydroxy aromatic amine is removed after the decomposition of the halomagnetol by water, which inevitably leads to the use of acids and a decrease in the yield of 5-ketols. The yield of the target product by this method reaches 75%. The use of this method allows the preparation of p-ketols sensitive to the action of acids.

The choice of solvents is determined by their property not to dissolve (not be mixed) with halogen magnesium ketolite and a low boiling point, which facilitates their subsequent regeneration.

To simplify the process of isolating the compaction product (halo-magnesium ketol), methyl magnesium chloride is used as the Grignard reagent. In this case, the magnesium magnesium chloride falls out in the form of a precipitate, which is easily separated, and then decomposed with water, and the desired product is removed using known methods.

Example 1. An absolutely ethereal solution of 0.24 g mol of ethylaniline was added to a Grignard reagent prepared from a 0.25 g-atom of magnesium with external cooling. Then, an absolutely ethereal solution of pinacoline (0.24 mol) was added to the obtained halogenmagnesium ethanilinate within 20 minutes while cooling to -15 ° C. After 30 min exposure, a completely ethereal solution of an equivalent amount of acetophenone (0.24 mol) is introduced into the reaction for 10 min at. 150 ml of absolute hexane is added to the reactor to separate the fatty aromatic amine from the halomagnetite. The reaction mixture is stirred and allowed to stand for several hours, and separation is observed. The upper (ether-hydrocarbon) layer is separated from the lower one containing halogen-magnesium ketol. After decomposition, the lower layer is extracted with ether. The ether extracts are washed with sodium thiosulfate solution, water, and dried with anhydrous sodium sulfate. After filtering and distilling off the ether and the solvent (hexane), the resulting α-ketol is recrystallized from hexane. In the case of chlorine magnesium ethylaninate, the formation of a precipitate is observed, easily separable from the upper layer. The resulting 2,2-dimethyl-5-phenyl-5-hydroxyhexa-3-o has a mp. 74.5C. Found,%: C76.5: H, 9.2; OH 7.8;

M 222. Calculated,%: C, 76.32; H 9.15;

OH 7.72; M 220.29.

The output of 33 g - 60% of theoretical. All subsequent examples are carried out under conditions analogous to example 1.

Example 2. 2,2-Dimethyl-5-phenyl-5-hydroxyhexane-3-one is obtained by compacting 0.24 mol of pinacoline and 0.25 mol of acetophenone, but carbon tetrachloride is used as a solvent to remove the secondary aromatic amine.

The output of 33.5 g - 61% of theoretical.

Example 3. By compacting equimolar amounts (0.24 mol) of pinacoline and acetophenone, 2,2-dimethyl-5-phenyl-5-hydroxyhexane-o-o is prepared as a solvent to remove the fatty-aromatic amine using secondary butyl chloride.

Output 33 g - 60% of theoretical

Example 4. 2,2,5-Trimethyl-6-phenyl-5-hydroxyhexan-3-one is obtained by compacting pinacoline and methyl benzyl ketone, mp. . Found,%: C 76.7; H 9.3; OH 7.0;

M 233.

Calculated,%: C, 76.88; H 9.46;

OH 7.25; M 234.22. OH 7.25; M 234.22.

Output 43 g - 75% of theoretical

Example 5. 2-Methyl-5-phenyl-5-hydroxyhexane-3-one is obtained by densification of methyl isopropyl ketone with acetophenone. m.p. 6O-61 C.

Found,%: C 75.5; H 8.8; OH B, b;

M 209

Calculated,%: C 75.69; H 8.77;

OH 8.23; M 206.27.

Yield 35 G (70%).

Example 6. When compaction of methyl ethyl ketone with acetophechone, 2-phenyl-2 oxyhexan-4-one is obtained, m.p. 57-5bs.

Found,%: C 7.8; H 8.2; OH 8.5; M 193

Calculated,%: C, 74.97; H 8.38; OH 8.83; M 192.24.

Yield 33 g (71%).

Example 7. 2,2,5-Trimethyl-5-hydroxyhexan-3-one is obtained from pinacoline and acetone.

Found,%: C 68.2; H 11.3; OH 10, M 155

Calculated,%; C 68.35; H 11.49;

OH 10.73; M 158.23.

Yield 29 g (75%).

Example 8. 2,2,5-Trimethyl-5-hydroxyhexan-3-one from pinacoline and methyl ethyl ketone.

Found,%: C 69, :); M 11.6; OH 9.J;

M J71 Calculated: С O9.77; H 1.63;

OH 9.86; M 172.5. Yield 32 g (75%),

Formula.la invention

The method of producing 5-ketols by reacting ketones with ketones in an absolute solvent at a temperature of from -15 to in the presence of Grignard reagent and a secondary fatty aromatic amine decomposing the resulting halogen-magnesium ketol with water and removing the secondary fatty-aromatic amine, which is in order to increase the yield of the target product, the secondary fatty aromatic amine is removed from the reaction mass by extraction with an absolute solvent selected from the group: hexane, carbon tetrachloride or mono Chlorophenyl of the total form: R-C1, where R-C, is either CjH or second, before the decomposition stage of halo-magnesium ketol and ta.

Sources of information taken into account in the examination

1.Esafov, VI,; HOX, 30, 3272, 1960.

2.I.E.Dubois, G.Scbutz, I.-M.Normant. Synthesis of tert-butyl ketohes from tertko.tols. Bull.Soc,

Chim. France 11, 3578, 1966.

3.V.Grignard, I.Cononqe, Compete rendus hebdomadaires des siances de IAcademie de Sciences, 194, 929, 1932 (prototype).

Claims (1)

Claim A process for preparing | 3-ketol by reacting ketones with ketones in ^'υ absolute solvent medium at a temperature of from -15 to -18 ° C in the presence of Grignard reagent and aliphatic-aromatic secondary amine with the resulting decomposition galogenmagniy15 ketolyata removing water and aliphatic-aromatic secondary amine of the Leech t in order to increase the yield of the target product, the secondary aromatic fatty · 20 amine is removed from the reaction mass by extraction with an absolute solvent selected from the group: hexane, carbon tetrachloride or monochlorapkyl of the general formula R-C1, where RC ^ Hg- or 25 CjH _? or sec-C ^ H ₉ , before the decomposition stage of the halogen-magnesium ketolate.