DE1283215B - Process for the production of organic iodides - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN ATVS PATENT OFFICE

EDITORIAL

Int. α .:

German class:

Number:
File number:
Registration date:
Display day:

C07c

C07f

12 ο -2/01

12 ο -19/02

12 ο-26/03

P 12 83 215.4-42 (A 48092)

January 11, 1965

November 21, 1968

Organic iodides are currently produced by reacting an alcohol with an inorganic one Iodide and sulfuric acid or phosphoric acid or by reacting an alcohol with red phosphorus and iodine. Both methods have considerable disadvantages: the first method is because because sulfuric acid is an oxidizing agent, so that there are low yields of the organic halide result, and phosphoric acid is expensive, and the second process because of side reactions which lead to Can lead to production of phosphoric esters, and also because of the high cost of the reactants, which makes the operation of the process on a large or industrial scale uneconomical.

The invention now relates to a method for the production of organic iodides, which thereby is characterized in that one alkali or ammonium iodides with monovalent, primary or secondary Alkyl or alkenyl alcohols which have up to 20 carbon atoms and, if appropriate, are subject to the reaction conditions Have inert substituents in the presence of gaseous hydrogen chloride and an inert liquid reaction medium, reacted at 50 to 250 ° C, wherein the The weight ratio of water present during the reaction to hydrogen chloride always increases does not hold more than 6: 1.

Surprisingly, the end product is mostly the organic iodide and not that organic chloride as would be expected. This process leads to the production of organic Iodides in satisfactory yield. Any chloride contamination can possibly through the appropriate fractional distillation process can be removed. There is also hydrogen chloride in this process is used as the third reactant in the system, it is a much more economical process in operation than the previously mentioned methods used.

Useful substituents on the alkyl groups of the alcohols used are halogen atoms, in particular Chlorine or fluorine, and aryl groups or substituted aryl groups in which the substituents are also inert. Olefinic double bonds are in the present context also to be regarded as inert substituents. Examples of usable alcohols are methanol, ethanol, propanol, Isopropanol, sec-butanol, n-hexanol, octanols, Nonanols, / I-phenylethanol, trifluoroethanol, 3,3,3-trifluoropropanol and benzyl alcohol, dodecyl or lauryl alcohol and allyl alcohol.

Optionally, mixtures of the above methods of preparation can be used
of organic iodides

Applicant:

Albright & Wilson Ltd., Oldbury,

Warwickshire (UK)

Representative:

Dr.-Ing. Hans Fincke, Dipl.-Ing. Herbert Bohr
and Dipl.-Ing. Sigurd Staeger, patent attorneys,
8000 Munich

Named as inventor:
Harold Coates, Wombourn, Staffordshire;
Peter Albert Theodore Hoye, Kinver Dunsley,
Stourbridge, Worcestershire (UK) - -

called iodides can be used. The iodide used can be in suspension in the reaction mixture or preferably be present in solution in a liquid medium. Preferably the Lithium, sodium and potassium salts are used as they are in the liquid normally used Media are readily soluble.

Since limited amounts of water may be present in the reaction mixture, as follows may optionally be a concentrated aqueous solution of the inorganic halide be used.

The reaction process is carried out using gaseous hydrogen chloride in the presence of a liquid medium carried out. This can only be the excess of the alcohol reactant, which progressively dissolves with the organic iodide mixed, be. Gaseous hydrogen chloride is passed into the reaction mixture during the reaction, or the gaseous one is used Hydrogen chloride to presaturate the alcohol. The presence of too much water in the reaction mixture must be avoided, and so must the overall weight ratio of water to hydrogen chloride must not be 6: 1 at any time during the conversion exceed. It is possible to use dilute hydrochloric acid in the process according to the invention does not provide a satisfactory rate of reaction, however, and it is preferred to use concentrated To use acid. Other inert liquids that

809 638/1713

also part of the reaction medium form a lower layer with a content of the organic substances, include: organic halides, which are niche components. The residue in the reaction unit Boiling point, which can easily separate the vessel can also contain some organic halide, the same from that produced during the reaction which did not distill. Hence be organic iodide is allowed, as well as hydrocarbons 5 the lower layer of the distillate and the residue substances, for example benzene, toluene, xylene and treated separately or together in the flask to Light petrol. to clean the product, for example by cleaning

Before introducing the hydrogen chloride, it is successive washings with water, then with desirable to change the device from oxygen to dilute aqueous alkali and again with water, clean or free, for example by an io The end product is then dried and nitrogen flow, since the oxygen has a tendency to oxidize further, if necessary by a second distillation des purified by the reaction of the alkyl iodide. Selective extraction with Has hydrogen iodide generated hydrogen chloride, process for the recovery and purification of the orgawas be used in reduced yields of the desired niche halide product, organic iodide. Preferably, the organic iodides are found as the reaction Device by blowing nitrogen through intermediate products, for example during manufacture freed from air. of organometallic compounds, in particular

For an essentially complete conversion of Grignard reagents and organotin compounds, is said to be the inorganic iodide in stoichiometric use.

The invention will be based on the following examples to use excess alcohol, so that this excess can increase the amount of the liquid medium. . -I ₁

The reaction takes place at a temperature of 50 ü e 1 s ρ 1 e 1 1.

to 250 ⁰ C and very expediently under reflux at The reaction vessel consisted of one with one

Carried out at atmospheric pressure. It can sometimes be 25 airtight stirrer, a hydrogen chloride sparge is desirable be to use higher pressures to tube, a thermometer, a Dean essay increasing the temperature of the reaction mixture and Stark (Journal of Industrial and Engineering while keeping them in a liquid state. Wenn Chemistry, 12 (1920), p. 486) and a condenser diluted Hydrochloric acid instead of gaseous chlorine see three-necked flask. An outlet from the radiator Using hydrogen or concentrated hydrochloric acid 30 resulted in a cold trap where any organic or larger amounts of water in the reaction material was removed from the hydrogen chloride stream, take part! The flask is filled with sodium iodide (600 g

much of the water is removed from the reaction mixture while refluxing 96.2% sodium iodide and butyl alcohol (889 g). This was charged, and any air present was flushed out or displaced with distillate of the refluxing reaction mixture in a nitrogen stream, mixture is often an azeotropic mixture , initiated while the will as well as that existing from the beginning), the temperature of the mixture from room temperature to reactants alcohol and the alkyl iodide. about 70 ⁰ C rose. When no more hydrogen chloride was removed, the azeotropic mixture was preferably sorbed in 40, the inflow rate of a separator of the gas was reduced and the temperature of the distilled, where the mixture was raised to the reflux temperature in two layers of mixture. It can be separated into an upper aqueous layer, an azeotropic mixture of butyl, which also contains some alcohol reactants, is iodide, butanol and water, and the distillate can keep separated if it is miscible with water, 45 separates into a lower layer Butyl iodide and butanol and into a lower organic layer. The organic and in a top layer of butanol and water. Layer is returned to the reaction mixture. The distillate was collected and more and the aqueous layer is discarded or used in addition to butanol (up to a total of 148 g) to the reaction mixture or otherwise added in a conventional manner to remove that with the distillate to compensate or replace any alcohol and alcohol halide held therein. The reaction mixture was refluxed

However, if the alcohol is heated to a high molecular weight until no more water distilled, which is about this can take up 9 hours in the reaction mixture. Then it became with Distill any water left over until the residue left in the flask has evaporated the reaction mixture is reached. 55 united distillate several times with water, diluted In this case, you can use the water from the separating caustic soda solution and then again with the water device or let the separator run off, wash and finally dry, which makes the and discard until the distillate gave some azeotropic butyl iodide product. This butyl iodide product Mixture contains. weighed 881.5 g and was found to consist of a

The reaction products are recovered from the reaction mixture by conventional 60 mixture of butyl iodide and butyl chloride. While there were 22.5 percent by weight of the latter rend of the reaction, the products were contained in the all-compound. The yield was 96.5% of the common boil under reflux and theory, based on the inorganic used, is allowed to distill off only in the final stages. This iodide.
Distillate is often an azeotropic mixture from the 65th

organic halide product, the alcohol reaction example 2

participants and water. This distillate separates. The procedure of Example 1 was repeated

generally in an upper aqueous layer and fetches, but with concentrated aqueous hydrochloric acid

(specific gravity 1.16) was used instead of gaseous hydrogen chloride. In addition, the Dean and Stark attachment was modified in the device so that the lower layer of the azeotropic distillate was returned to the reaction flask and the water was removed periodically. Butanol (222 g), sodium iodide (150 g) and hydrochloric acid (100 cm ³ ) were added to the flask and heated to reflux temperature with constant stirring. The reaction mixture was kept at reflux temperature until no more water distilled off, the water being removed from the modified Dean-Stark attachment from time to time during the course of the reaction. The temperature rose from 96 to 111 ° C during this stage and the reaction time was 4 hours. The product mixture of butanol and butyl iodide was purified as in Example 1, yielding 204.4 g of butyl iodide product contaminated with 6.8 weight percent butyl chloride. The yield almost corresponded to the theoretical yield based on the inorganic iodide used.

Example 3

The procedure of Example 2 was repeated using butanol (889 g), sodium iodide (600 g, 98.75% purity) and concentrated aqueous hydrochloric acid (400 cm ³ , specific gravity 1.16). The reaction time was increased to 9 hours.

The product mixture of butanol and butyl iodide was purified as in Example 1, resulting in 632 g Butyl iodide product contaminated with a trace of butyl chloride.

Example 4

The procedure of Example 2 was repeated, except that 93% pure sodium iodide was used Instead, the same amount of 98.75% pure sodium iodide was used. The reaction time was increased to 19 hours.

The product mixture of butanol and butyl iodide was purified as in Example 1, whereby the theoretical yield of butyl iodide based on the sodium iodide used.

Example 5

In the apparatus used in Example 2 Allyl alcohol (174 g), sodium iodide (150 g, 96.2 ° / _o pure) and concentrated aqueous hydrochloric acid (400cm ^3, specific gravity 1.16) was introduced. The temperature of the reaction mixture was raised to the reflux temperature and refluxed for 2 hours with constant stirring. After 2 hours, an azeotropic mixture of allyl iodide, allyl alcohol and water was slowly distilled off over the next 5 hours. The distillate was collected, washed once with an equal volume of water and then dried.

The yield of the product mixture of allyl alcohol and allyl iodide was 146.5 g and it was found a yield of 50.6 g of allyl iodide.

Example 6

The procedure of Example 2 was repeated using sec-butyl alcohol (222 g), sodium iodide (150 g, 96.2% purity) and concentrated aqueous hydrochloric acid (100 cm ³ , specific gravity 1.16). The reaction time was 6 hours. The resulting product mixture of sec-butyl iodide and sec-butyl alcohol was washed with water and then dried, resulting in a yield of 133.7 g of sec-butyl iodide contaminated with 6.9 g of sec-butyl chloride.

Example 7

Octadecyl alcohol (270.5 g) and sodium iodide (150 g) were poured into a tube equipped with a stirrer, a hydrogen chloride gas inlet tube, a thermometer and one set up or arranged for the distillation Introduced flask equipped with a cooler. The reaction mixture was heated to 80 ° C, and the device was then purged with a stream of nitrogen. Then it became hydrogen chloride gas

ao passed through the reaction mixture in the course of the reaction. The temperature was gradually increased while I ¹ It hours at 125 ° C and then held for 3 hours at 125 ± 3 ° C. In the course of the reaction, water was distilled off.

The reaction products were washed with hot water (55 to 6O ⁰ C), then with hot dilute caustic soda solution and finally again with hot water, whereby 308 g Octadecyljodid were obtained.

Example 8

It was a reaction mixture containing [2-ethyl] hexanol (130 g), sodium iodide (150 g) and concentrated aqueous hydrochloric acid (100 cm ³ , specific gravity 1.16) in a with a stirrer, a thermometer and a introduced for the distillation equipped or arranged condenser provided flask. The reaction mixture was heated to 112 ° C. with stirring, at which temperature water began to distill off. The reaction was continued for 7 ^x / ₄ hours during which time a total of 100 cm ^{3 of} water was collected. The reaction products gave 173.5 g of [2-ethyl] hexyl iodide.

Claims (3)

Patent claims: 1. Process for the production of organic iodides, characterized in that that one alkali or ammonium iodides with monovalent, primary or secondary alkyl or Alkenyl alcohols which have up to 20 carbon atoms and, if appropriate, are subject to the reaction conditions have inert substituents in the presence of gaseous hydrogen chloride and an inert liquid reaction medium, at 50 to 250 ° C, the weight ratio of water present during the reaction to hydrogen chloride always at no more than 6: 1. 2. The method according to claim 1, characterized in that there is used an excess of alcohol. 3. The method according to claim 1 and 2, characterized in that instead of gaseous Hydrogen chloride aqueous hydrochloric acid is used. 809 638/1713 11. 68 ι Bundesdruckerei Berlin