DE1217951B - Process for the preparation of alkyltin halide mixtures with a high proportion of dialkyltin dihalides - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C07f

German class: 12 ο - 26/03

Number: 1217 951

File number: D 45397IV b / 12 ο

Filing date: September 12, 1964

Opening day: June 2, 1966

The technical production of alkyltin halides nowadays essentially takes place according to two processes, both of which use tin tetrachloride as their starting material. One method is called Alkylating agent a Grignard compound and an aluminum alkyl compound applied to the other. In order to achieve good results, both procedures are carried out in such a way that one starts with the corresponding tetraalkyltin produces. This is then in a further reaction with tin tetrachloride ίο co-proportioned.

These methods are not entirely satisfactory because they are relatively complicated and costly to carry out is. There is therefore a need for a simplified process. The optimal solution is in it too see if

1. the desired organotin compound in a one-step process instead of a three-step process as before can be obtained;

2. an organometallic alkylating not ER- ^ao is conducive;

3. The cheaper metallic tin can be used as the starting material instead of tin tetrachloride can;

4. the process without highly flammable solvents that can be recovered at expense can be carried out.

Although there are some known processes in which metallic tin with alkyl halides directly to Alkyltin halides is implemented. These direct syntheses can only be achieved with particularly reactive ones Alkyl halides. Direct syntheses with higher alkyl chloride homologues leading to a technical usable yield are not known.

In connection with Example 1, an experiment is described in which tin is added with octyl chloride of magnesium as a catalyst is converted by a known method. After a reaction time of 5 hours, only 11.1% of the tin had, namely below mainly formation of inorganic tin compounds.

For the production of heat and light stabilizers for plastics, those of organotin compounds derived from higher alkyl homologues are of great importance, since they are a much smaller Exhibit toxicity as the methyl, ethyl, propyl and butyl tin compounds and as physiological harmless stabilizers can be used.

It has now been found that alkyltin halides under the conditions described at the beginning as optimal for the preparation of
Alkyl tin halide mixtures with high
Share of dialkyltin dihalides

Applicant:

German Advance Production G. m. B. H.,

Lautern (Odenw.), Nibelungenstr. 4th

Named as inventor:

Dr. Wolfgang Jasching, Koenigsbrunn;

Dr. Volker Franzen, Heidelberg

can be produced in good yield. The invention relates to a method for production of alkyltin halide mixtures with a high content of dialkyltin dihalides by reaction of tin with alkyl halides at elevated temperature in the presence of catalysts, which thereby is characterized in that arsenic or antimony trihalides are used as the catalyst in amounts of 1 to 8 mol percent, based on the tin used, and optionally additionally a dialkyltin dihalide, its Alkyl groups correspond to those of the alkyltin halides to be prepared, used.

The conversion is achieved in a single process step and corresponds to the reaction equation:

2 RX + Sn = R ₂ SnX ₂

(R = alkyl; X = halogen).

In this process, dialkyltin dihalide is always obtained as the main product. Next to it arises some monoalkyltin trihalide and little trialkyltin monohalide.

The metal halide catalysts which can be used according to the _{invention are: AsCl 3 , AsBr 3} , AsJ ₃ , SbCl ₃ , SbBr ₃ and SbJ ₃ .

It has been shown that the reaction can be accelerated in some cases, if in addition to the metal halides mentioned, a dialkyltin halide is added to the reaction mixture as a secondary catalyst, whose alkyl groups are preferably identical to those of the reaction product, in the concentration of 2 to 6 mol percent of the tin used.

For a rapid course of the reaction, it has also proven to be advantageous to use an excess of the reaction carry out of alkyl halide. The MoI

609 577/468

The ratio of tin to alkyl halide is generally 1 in 3.0 to 7. Is less reactive Starting out from alkyl halides, especially the higher alkyl chlorides, it can be advantageous to use these one add more reactive alkyl halide. The amount of this additive can be far below the stoichiometrically required amount. Suitable are, for example, mixtures of tin, alkyl chloride, alkyl iodide in a molar ratio of 1 to 3 to 7 to 0.1 to 0.4 or tin, alkyl chloride, alkyl bromide in a molar ratio of 1 to 3 to 6 to 0.2 to 1.3.

The addition of a solvent is not necessary to carry out the process according to the invention. In the case of particularly reactive alkyl halides, a solvent can optionally be used as a diluent be added if you want to reduce the reaction rate.

Another advantage of the process is that that it is largely independent of the shape and grain size of the tin used. It's not just possible with the finest tin powder, so-called tin grinding, but also with coarser tin powder or tin foil and even perform with tin shavings.

It has proven advantageous to carry out the reaction with the exclusion of moisture.

The reaction time is surprisingly short even when using the alkyl chlorides. With these it amounts to depending on the type and amount of additives used and depending on the reaction temperature, generally between 45 minutes and 6 hours. In the more reactive alkyl halides, e.g. B. the bromides, is the reaction time sometimes even shorter.

The reaction is generally carried out at temperatures between 100 and 200.degree. These limits however, in individual cases it can also or fall below.

The work-up of the reaction mixture and purification of the alkyltin halides can be carried out according to known methods Methods, e.g. B. by means of distillation, take place »

In the work-up, the alkyl halide used in excess can be almost completely removed by distillation regain. Likewise, additives can optionally be added during the reaction of alkyl chlorides Recovering alkyl iodide from the reaction mixture by distillation; like numerous attempts have shown that 50 to 80% of the alkyl iodide remains unused in the reaction.

The monoalkyltin trihalides obtained as a by-product are also valuable intermediates.

Compared to the previously customary Grignard synthesis, the new process has the advantage that it is a significantly less time and equipment required. A significant advance is also see that the cheaper alkyl chlorides, especially those with more than 4 carbon atoms, can be used for direct synthesis.

example 1

A mixture of.

18.0 g tin, finely powdered

(Grain maximum 6 to 25 μ),
150.0 g n-octyl chloride,
7.6 g n-octyl iodide,
6.0 g of antimony (Iir) iodide

was in a vessel with a water separator with stirring and reflux for 70 minutes to about Heated to 180 ° C. The clear reaction solution, which no longer contained any tin, was then distilled. 91.6 g of excess octyl chloride and 5.4 g of unused ethyl iodide were recovered. The distillation residue of 68.0 g contained 41.2 g of pure dioctyltin dichloride (65.5% of theory), 10.5 g of pure monooctyltin trichloride (20% of theory), traces of trioctyltin monochloride and

ίο some tin (II) chloride.

A comparative experiment without the catalyst according to the invention gave the following:

A mixture of

18.0 g tin, finely powdered

(Maximum grain size 6 to 25 μ), 150.0 g n-octyl chloride,
7.6 grams of n-octyl iodide

was heated to about 180 ° C. in a vessel with a water separator while stirring and refluxing. To No tin had been converted for 8 hours.

In addition, the following comparative experiment was carried out according to a known method in which magnesium in

The presence of an alcohol and an ether acts catalytically.

A mixture of Tin, finely powdered 18.0 g (Grain maximum 6 to 25 μ), n-octyl chloride, 67.0 g n-octyl iodide, 4.3 g n-octanol, 2.7 g Diethylene glycol diethyl ether, 12.0 g

0.18 g of magnesium powder

was heated for 5 hours at about 18O ⁰ C in a vessel with stirring and reflux. After this reaction time, 16.0 g of unused tin and 1.5 g of tin (II) chloride were present in the reaction mixture. So only 11.1% tin reacted, some of which was used to form undesirable inorganic tin compounds.

Example 2

A mixture of

18.0 g tin, finely powdered (maximum grain size 6 to 25 "μ),

150.0 g n-octyl chloride,
7.6 g n-octyl iodide,
1.8 g. Antkaon (III) chloride

was heated in an apparatus with water separator under reflux at about 180 ⁰ C. Here, the tin was consumed within ₂ hours to 6V to a residue of 0.3 g. After the excess n-octyl chloride and n-octyl iodide had been distilled off, a residue of 48.0 g (Sn content: 28.64%) remained. This consisted mainly of dioctyltin dichloride and monooctyltin trichloride. After AbdestiUieren of Monoocrylzinntrichlorids C was hydrolyzed with 2N NaQH at 100 ^0th This gave 28.3 g of dioctyltin oxide (Sn content: found 33 * 05%; calculated 32.85%). The monooctyltin trichloride fraction was also saponified and gave 8.9 g of octylstannonic acid (Sn content: found 44.2%; calculated 44.9%).

A mixture of

18.0 g tin, finely powdered

(Grain maximum 6 to 26 μ),
150.0 g n-octyl chloride,
7.6 g n-octyl iodide,
1.8 g antimony (III) chloride,
2.0 g of dioctyl zinc dichloride

was heated in an apparatus equipped with water under stirring and reflux at about 18O ⁰ C. The tin was consumed within 4 hours except for a residue of 0.4 g. After the excess octyl chloride and octyl iodide and the monooctyl tin trichloride had been distilled off, a residue of 47.8 g remained, which contained 38.0 g of pure dioctyl tin dichloride; after deduction of 2.0 g of dioctyl zinc dichloride, which were used as secondary catalyst, this corresponds to a yield of 57.0% of theory.

^ox y ^d (tin content: found 32.85%).

33.3%; calculated

Example*

A mixture of

18.0 g tin, finely powdered

(Grain maximum 6 to 25 μ),
150.0 g n-octyl chloride,
7.6 g n-octyl iodide,
1.8 g antimony (III) chloride,
2.5 g of antimony (III) iodide

was heated in an apparatus with Wasserabscherfer with stirring and reflux for about 18O ⁰ C In this case, the tin used within 2 hours was completely consumed after AbdestÄeren the excess octyl chloride and Octyljodids and the Monooctylzinntrichlorids em residue of 49.0 g of crude Dioctylzmndichlörid remained. When this residue was saponified, 31.4 g of dioctyltin oxide (tin content: found 33.0%; calculated 32.85%) were obtained in sodium hydroxide solution, corresponding to a yield of 57.5% of theory.

Example 5
A mixture of each

18.0 g tin, finely powdered

(Grain maximum 6 to 25 μ),
190.0 g n-octyl bromide,
4.0 g of antimony (Iir) iodide

was stirring

15th

Example 6

^{A voice from}

18.0 g tin, finely powdered

(Grain maximum 6 to 25 μ),
113.0 g octyl chloride,
³ ^ ^g O ^ct y ^lb romid,
⁶ > ° § Antimony (ni) iodide

was in a vessel Mt water separator with stirring and reflux for 45 minutes to about Heated to 180 ° C. After this time the tin was completely consumed. When working up the reaction mixture as in the previous examples occurred, 30.8 g of pure dioctyltin oxide were obtained.

Example?

^25th

³ °

35

a) heated to 190 C. After _{two and a} half hours all the tin powder had dissolved;

b) heated to 202 ° C. After 20 minutes it came in handy all tin powder gone into solution.

The clear reaction solution of batch b) was filtered off from the tin residue (0.1 g). From the filtrate the excess octyl bromide and the by-product were obtained by vacuum distillation Separated monooctyltin tribromide. The liquid still residue (68.5 g) consisted essentially from dioctyltin dibromide and some tin (II) bromide dissolved in it.

When this residue was saponified with 2N NaOH, 33.6 g (61.5% of theory) of dioctyltin-Ein were obtained Mixture of

18.0 g tin, finely powdered

(Grain maximum 6 to 25 μ),
179.0 g decyl chloride,
12.0 g decyl iodide,
6.0 g of antimony (III) iodide

was heated to 190 ° C with stirring for 4 hours. With the _{exception of a residue of 19 g, the} tin _{used was consumed after this time} . _{After the} reaction mixture had been filtered, the filtrate was distilled in vacuo in order to separate off excess decyl chloride, unused _{decyl iodide and the monodecyltin} trichloride formed as a by-product. 33.0 g of crude didecyl chloride _dichloride (tin content: found 26.1%; calculated 25%) were obtained as the distillation residue

Example 8

A mixture of

18.0 g tin, finely powdered

(Grain maximum 6 to 25 μ),
211.0 g lauryl chloride,
13.5 _g lauryl iodide,
6.0 g of antimony (III) iodide

was heated with stirring for 4 hours at 21O ⁰ C. After this time, 14.5 g of tin had been consumed. _{Bd the Aufarbe} itung that as was done in the previous examples, and subsequent saponification of the _ro hen Dilaurylzinndichlorids 23.5 g were Dilaurylzinnoxyd (tin content: found 24.8%; calculated 25.1%) was obtained.

example

_from

12.0 g tin, finely powdered

(Grain maximum 6 to 25 μ),
81.2 g n-hexyl chloride,

4.6 g n-hexyl iodide,

2.6 g of antimony (III) iodide

was shaken in a bomb tube at 180 ^° C. for 6 hours. 2.0 g of tin remained unused. Working up, which was carried out in the manner already described, gave 11.0 g of pure dihexyltin oxide (tin content: found 38.9%; calculated 39.0%).

Example 10
A mixture of

18.0 g tin powder (maximum grain size 6 to 25 μ),
167.0 g n-hexyl bromide,
4.0 g of antimony (Tn) iodide

Eg game 12

A mixture of

12.0 g tin, finely powdered

(Grain maximum 6 to 25 μ),
93.0 g n-butyl bromide,

3.9 g n-butyl iodide,
2.66 g of antimony (III) iodide

was heated in a vessel with reflux condenser while ίο 5 hours at 102 ⁰ C. 6.5 g (54.2%) of tin were converted here.

The same experiment was carried out without the addition of antimony iodide. After 5 hours of cooking Of the 12.0 g of tin, 11.9 g were still unused.

was stirred in a vessel with a reflux condenser and water separator for half a period Heated to 156 ° C for an hour. The clear reaction solution was nitrated from the tin residue (0.1 g). The FiI kicked was worked up as in Example 4. When the crude dihexyltin dibromide was saponified, it was obtained 37.5 g of dihexyltin oxide (57.5% of theory).

Example 13

B is ρ ie 1 11
A mixture of

18.0 g tin, finely powdered

(Grain maximum 6 to 25 μ),
45.0 g, 4-dichloro-2-butene,

200.0 g of diethylene glycol diethyl ether
(dried over sodium),
4.0 g of antimony (ni) iodide

was heated to 95 ° C. for 3 hours with stirring. 16.7 g of tin were converted. After filtration the reaction mixture was distilled. At first, dichlorobutene that had not been consumed was used as a preliminary fraction and diethylene glycol diethyl ether, then 33.6 g of the pure reaction product at 82 to 83 ° C / 0.05 Torr (Tin content: 24.7%; chlorine content: 31.5%) over.

A mixture of

18.0 g tin, finely powdered

(Grain maximum 6 to 25 μ),
150.0 g n-octyl chloride,
7.6 g n-octyl iodide,
2.5 g arsenic (Iir) bromide

was cooked in a vessel with water at about 18O ⁰ C with stirring under reflux. After hours, the tin was completely converted. In the work-up, which was carried out as in the other examples, 31.1 g of pure dioctyltin oxide were obtained.

Claims (1)

Claim: Process for the preparation of alkyltin halide mixtures with a high content of dialkyltin dihalides by reacting tin with alkyl halides at elevated temperature in the presence of catalysts, characterized in that that the catalyst used is arsenic or antimony trihalides in amounts of 1 to 8 mol percent, based on the tin used, and optionally additionally a dialkyltin dihalide, the alkyl groups of which are those of the ones to be prepared Alkyl tin halides are used. 609 577/468 5. 66 © Bundesdruckerei Berlin