SU361167A1 - - Google Patents

Description

METHOD OF OBTAINING ETHYLENE PRIMARY ALCOHOLS

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This invention relates to a catalytic method for the preparation of primary ethylene alcohols, which can be used as fragrances, as well as intermediate products in organic synthesis, for example in the synthesis of polymers.

A method of producing ethylene primary alcohols is known in which the solution of ethyl iodide in absolute ether is treated with sodium acetylide in liquid ammonia while cooled with a mixture of alcohol-solid carbon dioxide for 4 hours and the obtained butine-1 is treated with sodium amide suspended in liquid ammonia, a three-fold excess of ethylene oxide is added to the Na-complex thus formed and the reaction mixture is stirred for 24 hours at -40 ° C. Hexin-3-ol-1 (yield 47% on the starting ethyl iodide) is recovered by a known method and it is hydrogenated over palladium niello; at the same time receive hexene-Z-ol-1.

The known method is ineffective, very time consuming and based on the use of toxic and explosive substances.

In order to simplify the process, a method for preparing ethylene primary alcohols of the general formula RCH CH (CH.2) nCH2OH is proposed.

where R is hydrogen, alkyl; n is an integer from O to 10, the interaction of acyloxyalkane

acids with lead tetraacetate (TAG) at a temperature of 50-80 ° C in the presence of copper salts as catalyst, preferably copper diaschetat monohydrate, in an amount not

less than 0.1% of taken lead tetraacetate.

The process is best carried out in the presence of catalytic additives, such as a tertiary amine, in the absence of a solvent, and in a solvent, such as benzene.

Due to the inhibition of oxidative decarboxylation with air oxygen, the reaction is better carried out in an atmosphere of inert gas, for example nitrogen.

During the reaction, a mixture of two isomeric ethylene esters is obtained, which are isolated in the usual way. The obtained esters are converted by hydrolysis under known conditions into the corresponding unsaturated alcohols with a yield of up to 85-95% and are isolated

usual tricks.

The proposed method I | Vls most general, based on available raw materials, does not require complex equipment, is not associated with the use of toxic and explosive substances.

Example 1. 10 g (58.3 mol of 1-acetoxypentanecarboxylic-4 acid, 1 g of copper diacetate monohydrate, 5 ml of pyridine and 80 ml of benzene are loaded into a three-liter flask equipped with a stirrer, thermometer, reflux condenser, liquid shutter and device for purging the system Inert gas and powders of powdered TAG. In the last device 24 g of TAG (purity 88.5%) are placed.GHCTeMy is flushed with nitrogen, the contents of the flask are heated to boiling (76-78 ° G) and with vigorous stirring gradually s, for 2 hours they are sent small portions of TAG. New batch After the introduction of the previous batch, the selection of GOo is controlled using a gas burette connected to the system, filled with saturated aqueous sodium chloride solution. After the addition of TAG is completed, the mixture is stirred at 78-80 ° G for another 0, 5 hours, then cooled, the precipitate formed is filtered off, washed with a small amount (30 ml) of ether or benzene, the filtrate is washed with 30 ml of 20% hydrochloric or 30% perchloric acid, then with an aqueous solution of sodium bicarbonate and water. Then, the solvent was distilled off from the reaction product, and 4.7 g of a mixture of pentene-3-ylacetate (yield 29%) and pentene-4-sulfonate (yield 47%) were separated from the residue by distillation in vacuum. The total yield of esters is 76%.

3.85 g of the mixture obtained is subjected to hydrolysis by boiling with a 20% aqueous solution of KOH for 8 hours.

The hydrolysis products are extracted with ether. After evaporation of the solvent and distillation, 2.4 2 mixtures of pentene-3-ol (35%) and pentene-4-ol (57%), m.p. 138-140 ° G. The total yield of alcohols 92% (on the original acetate).

The resulting unsaturated alcohols and their hydrogenation product, pentanol, were identified by gas-liquid chromatography using reference samples.

Example 2. From 15.0 g (80.0 mmol) of 1-acetoxyhexanecarboxylic-4 acid by the method described in Example 1, 7.4 g of a mixture of goxen-3-yl- and hexene-4-ylacetate, t.p. . 57 -60 ° G / 10 mmHg Art. Overall yield 75%

(see table).

As a result of hydrolysis of the mixture of the obtained acetates, a mixture of hexene-3-and hexene-4-ol, i.k. 153-156 ° G. The total yield of unsaturated spirton 93% (per. Acetate).

The rest of the tabulated results were carried out in a similar manner with small differences in the way the reaction mixture was treated and the desired product was isolated. For example, in Example 3, the solvent was distilled off immediately (without treatment with hydrochloric or perchloric acid, sodium bicarbonate solution and water) and the solvent was distilled off, and then the distillation of the residue was extracted with 9.5 g of a mixture of hepten-3-yl and hepten-4-ylacetate (t. Kil. 67-70 ° C / 9 mm Hg. Art.) and 10 g of a mixture of these acetates with pyridine and acetic acid. After washing with water, an additional 1.5 g of a mixture of hepten-3 or hepten-4-ylacetates is isolated from this fraction. Their overall yield is -100% (for PUMP in TAG reaction). According to a similar procedure, unsaturated alcohols are obtained from the alkene-acetates listed in the table with a yield of 5-95%.

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Subject invention

Claims (4)

1. A method for producing ethyl 1 perbich operats of the general formula RCH GH (CH2) nCH2OH, where R is hydrogen, alkyl; p is an integer from 0 to 10, characterized in that, in order to simplify the process, the acyloxyalkanoic acid is reacted with lead tetraacetate at 50 ° C in the presence of a copper salt as a catalyst. the esters thus obtained are subjected to hydrolysis under known conditions and the desired product is isolated by conventional techniques. 2. A method according to claim 1, characterized in that the process is carried out in an inert solvent, for example benzene. 3. Method according to paragraphs. 1 and 2, characterized in that the process is carried out in the presence of a tertiary amine as a catalytic additive. 4. Method according to paragraphs. 1-3, characterized in THAT copper diacetate monohydrate is used as the copper salt.