DE1055519B - Process for the preparation of ethers dihalogenated in the 1,2-position - Google Patents

Description

GERMAN

The invention relates to a process for the preparation of dieters of the dihalogenated glycols.

It is known that the monohalogenated monoethers of the general formula ROCH ₂ X can be obtained by reacting a monoaldehyde with an alcohol and hydrohalic acid.

Even if the existence of the dihalogenated dieters, i. H. more complex connections that are im Molecule containing two halogens and two ether oxide groups had been foreseen, so one had due to the mutual influence of these diverse functional groups depending on the ones observed Working very different variants of this group of compounds, such as symmetrical or asymmetric, cyclic or acyclic compounds, etc., can be expected.

The attempts to make the symmetrical dihalogenated dieters are consistently high Complicated procedural paths have been taken, as it is based on theoretical considerations and practical experience seemed unlikely that this, especially in the presence of Water very unstable compounds are accessible in a simple way.

The reaction between a dialdehyde such as glyoxal, an alcohol and a hydrohalic acid did not seem to have any prospect of success, if only because this reaction was under Formation of water runs. Rather, it was known that under these circumstances the stable connection d. H. the asymmetrical connection.

Contrary to all expectations, it has been found that the cyclic or acyclic ethers this dihalogenated diether of the general formula

or

XHC-

I. ο

XHC
O

-CHX
O
R.

-CHX
, 0

(1)

(2)

wherein X is a halogen, R is an aliphatic radical, such as CH ₃ -, C ₂ H ₅ -, and R 'is an alkylene group, such as -CH ₀ -CH ₂ -, can be prepared in such a way that glyoxal with a Alcohol or glycol and a hydrohalic acid.

for the production of in 1,2-position
dihalogenated ethers

Applicant:

Bozel-Maletra Societe Industrielle

de Produits Chimiques ,

Paris

Representative:

Dr. GW Lotterhos and Dr.-Ing. HW Lotterhos,
Patent attorneys, Frankfurt / M., Lichtensteinstr. 3

Claimed priority:
France 16 September 1954

Jean-Claude Bondiou, Gentilly, Seine,
and Josef Lintner, La Carenne Colombes, Seine

(France),
have been named as inventors

The procedure here is that the glyoxal in the form of an aqueous concentrated solution or dissolves in powder form in excess alcohol or glycol, cools the solution, then into the Introduces solution of hydrogen chloride, preferably in a gaseous state, and separates the dihalogenated diether, either by allowing the mixture to crystallize or by extracting it with a solvent. Suitable alcohols for carrying out the process include methyl alcohol, ethyl alcohol, Butyl alcohol, ethylene glycol in particular can be mentioned as a glycol.

Hydrogen halide acids are suitable, depending on the desired end products, the hydrogen chloride and hydrobromic acid.

In order to facilitate the dissolution of the glyoxal, a certain amount can be added to the solution that forms Introduce amount of hydrochloric acid. In the same way, the solution containing the dialdehyde only add the alcohol after the introduction of the gaseous hydrochloric acid.

Methylene chloride, carbon tetrachloride, ethyl ether, etc. can be used as extractants. The dissolution of the dialdehyde is promoted by heating and / or stirring the mixture.

909 507/565

The introduction of the hydrohalic acid must be carried out at a sufficiently low temperature, so that the dihalogenated ethers formed do not react with the excess alcohol, preferably one works at temperatures below 25 ° C.

With the method of the invention one can obtain a certain number of new compounds that are chemically and are physically well characterized. They are crystalline or liquid compounds, which are insoluble in water, but easily dissolve in organic solvents. In present they are saponified by water to form the starting materials. In the absence of water they are completely stable and can be purified by distillation.

The properties of these dihalogenated dieters are extraordinary for organic synthesis important because they make the mobile halogen atoms very reactive agents. You are suitable especially for condensation with all alcoholic or phenolic HO groups and thus enable the formation of numerous new diacetals. In the same way they react with compounds that are moving Have H or metal atom, especially with the hydrogen atom of carboxylic acids.

The alkoxy group RO— these dihalogenated dieters can be used in the same way with compounds of the aromatic series are condensed, making the synthesis of the compounds easy and economical the diphenylethane group

2ArH + R-O-CHX-CHX-O-R - * -

Ar-CHX-CHX-Ar-r ^ R-OH

is made possible.

Finally, the process of the invention makes a significant advance in synthesis Reached products that were previously only accessible with difficulty. This applies to, for example 2,3-dichlorodioxane, which so far only by chlorination could be obtained from dioxane and by the process of the invention from glyoxal ethylene glycol and hydrochloric acid can be produced.

example 1

Mix 220 parts by weight of glyoxal in the form of a 78% strength powder with 425 parts by weight of methyl alcohol leads to about 10 parts of gaseous form in the mixture Hydrochloric acid and heated with stirring to 40 to 50 ° C until completely dissolved. It is then cooled to a temperature between 0 and 15 ° C. and 365 parts are passed within 4 hours dry gaseous hydrochloric acid. A plentiful amount of crystals is formed, which one initially needs with a little cold methyl alcohol, then washes with cold ether. 380 parts of pure are obtained Dimethoxydichloroethane. Melting point 70.5 ° C., chlorine content 44.2% (calculated 44.6%), yield 80%.

Example 2

A mixture of 220 parts by weight of glyoxal in the form of 78% strength powder and 425 parts of methyl alcohol in the manner described in Example 1, with the exception that the Hydrochloric acid replaced with 810 parts of gaseous hydrobromic acid. Dimethoxydibromoethane is obtained, which is immediately recrystallized from carbon tetrachloride. The end product has a Mp. Of 72 ° C, its bromine content is 60% (calculated 64.5%).

Example 3

A solution of 50% glyoxal, the 435 parts by weight of glyoxal to 100% dissolved in 435 parts of water contains, 1330 parts of methylene chloride are mixed in, and gaseous hydrochloric acid is passed into this mixture to saturation while maintaining the temperature at around 0 ° C. Then you lead slowly 690 parts of ethyl alcohol, while continuing the introduction of hydrogen chloride and the temperature keeps at about 0 ° C. After saturation, separate the lower layer, which is made up of a mixture composed of diethoxydichloroethane and methylene chloride. For example, you overdry them Calcium chloride and distilled it under reduced pressure. In this way, 1100 parts of diethoxydichloroethane are obtained, which distills at 40 mm pressure at 90 ° C, has a density of 1.135 at 20 ° C, Has a melting point of 17 ° C and its chlorine content is 37.1% (calculated 38%).

Example 4

In a mixture consisting of 500 parts by weight of a 60% glyoxal solution, 284 parts of ethylene glycol and 800 parts of carbon tetrachloride are carried out in gaseous form with thorough stirring and low pressure Hydrogen chloride until the mixture is saturated, keeping the temperature below of 5 ° C. The mixture is left to stand for a few hours at ordinary temperature, then decanted the lower layer, which is composed of carbon tetrachloride and diichloro-oxaine. The upper Layer is renewed with hydrogen chloride in the presence of a further amount of 800 parts Saturated carbon tetrachloride. This measure is repeated three times. The four mixtures of carbon tetrachloride and dichlorodioxane are distilled under reduced pressure. You finally get 193.5 parts of pure 2,3-dichlorodioxane, which in a Pressure of 23 mm passes between 89 and 95 ° C. The reaction produces practically no by-products.

Claims (2)

Patent claims. 1. Process for the preparation of 1,2-position dihalogenated ethers, characterized in that glyoxal with an alcohol or a glycol and gaseous hydrohalic acid to ethers of dihalogenated ethane derivatives of the general formula or XHC
O
R. XHC- -CHX
O -CHX O O wherein X is a halogen, R is an aliphatic radical, such as CH ₃ -, C ₂ H ₅ -, and R 'is an alkylene group, such as - CH ₂ —CH ₂ - · is converted. 2. The method according to claim 1, characterized in that glyoxal in excess alcohol or dissolved glycol is used for the reaction. Considered publications:
German patent specification No. 906 454. © 909 507/565. 4.59