DE1167345B - Process for stabilizing organotin hydrides - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: C07f

German class: 12 ο -26/03

Number:
File number:
Registration date:
Display day:

St 17092 IVb / 12 ο

November 8, 1960

April 9, 1964

For the preparation of organotin _{hydrides of the general formulas R 3} SnH, R ₂ SnH ₂ and RSnH ₃ (R = alkyl or aryl), several processes have become known to date. Metal compounds, ζ. Β. (CH ₃ ) ₃ SnNa or (C ₆ H ₅ ) ₃ SnLi, reacted with NH ₄ Cl or NH ₄ Br to give the corresponding hydrogen compounds. However, these reactions are complicated to carry out. The yields reach a maximum of 33% of theory, but they are usually much lower. The attempts to obtain organotin hydrides from the corresponding halides in ethereal solution by reduction with lithium aluminum hydride were more successful. A number of substances of the general formula R «SnH _{4 - re} (n = 1, 2, 3) were produced in this way on a laboratory scale with satisfactory yields. Carrying out this reaction on a larger scale, however, stands in the way of the laborious work-up required, all of the by-products of which are also worthless, and the high price of the lithium aluminum hydride. Use of the cheaper alkali or alkaline earth metal hydrides led, if at all, to conversion only under the application of pressure and higher temperatures. Under such conditions, however, the desired reaction products are decomposable.

Recently it has been proposed to prepare alkyltin hydrides using the corresponding Halides with the help of complexly bound and thus made more soluble sodium hydride to reduce.

It has also been proposed to use sodium hydride to reduce alkyl tin halides and to add a small amount of boron or aluminum alkyl compound as a catalyst. With this in mind with NaH (commercially available product), Bortriäthyl and triethyltin at 65 to 70 ⁰ C carried out in a high boiling mineral oil mixture gave, after distillation at 33 torr but only 37 ° / ₀ of theory of Triäthylzinnhydrid, deviated again Zinntetraäthyl and a dark-colored distillation residue. (In this and the above case, the hydride formed at least partially decomposed under the reaction conditions.) Recently, it has become possible to prepare organotin hydrides by reducing organotin halides with dialkylaluminum hydrides under mild conditions. The organotin hydrides produced can be isolated in the usual way of working up after hydrolysis of the organoaluminum compound, but it is often advantageous to distill them off directly from the reaction mixture. Also organotin hydrides produced in this way. are often fickle and methods of stabilizing
Organotin hydrides

Applicant:

Study Society Coal m. B. H.,

Mülheim / Ruhr, Kaiser-Wilhelm-Platz 2

Named as the inventor:

Dr. Wilhelm Paul Neumann, Giessen,

Dipl.-Chem. Dr. Horst Niermann,

Cologne-Stammheim

decompose even at 0 ⁰ C over the course of several days under tin deposition and hydrogen.

It has now been found that traces of aluminum halogen compounds, which have been entrained in the steam during distillation, greatly accelerate this decomposition. Free the organotin hydrides from the aluminum compounds by shaking them out with a little water or better sodium bicarbonate solution, so their persistence increases considerably, so that they are generally kept for weeks (under Exclusion of air).

The invention relates to a method for stabilizing organotin hydrides, which thereby is characterized in that to remove the instability causing aluminum halogen compounds this in a manner known per se by treatment with a little water or preferably sodium bicarbonate solutions removed.

Example 1

A distilled triethyltin hydride containing small amounts of entrained diethylaluminum chloride is, after distillation, added dropwise with a little water or, better, NaHCO ₃ solution, the resulting turbidity (aluminum hydroxide) is filtered off, dried and distilled again. Bp ₁₂ = 47 ^° C. The tin content is then 57.4% (calculated for C ₆ H ₁₆ Sn: 57.4%), the yield 51.5 g = 83% of theory.

Example 2

In 34.5 g (0.4 mol) of diethyl aluminum hydride, powdered diethyl tin dichloride (49.6 g = 0.2 mol) was added in small portions in a stream of argon. The mixture soon becomes completely clear

409 558/461

Claims (1)

3 4 Stir. After the reaction has ended, hydride is distilled afterwards the resulting diethyltin dihydride in vacuo, _{R SnC] + R A1H} ^ _{R SnH + R A1C} ,
decomposes entrained traces of diethylaluminum chloride with a few drops of water or better and isolated by direct distillation from the NaHCOs solution, dry and filtered. Yield 5 reaction mixture, intensely with 10 ecm one 31.8 g = 89% of theory. The tin content is saturated aqueous sodium bicarbonate solution. 66.4% (calculated for C ₄ H ₁₂ Sn: 66.4%), the product shakes. In this way, entrained diethyl is chlorine free. aluminum chloride destroyed. After separating the water The organic phase is dried with the 13th layer ίο some sodium sulfate. The triethyltin hydride, its 34.3 g (0.1 mol) of diphenyltin dichloride, dissolved in decomposition, otherwise becomes clear after 2 to 3 days, 200 cc of dry dibutyl ether, are added at 0 ⁰ C for months after the stabilization unchanged or something below it gradually into the solution of durable. 17.5 g (0.2MoI) diethyl aluminum hydride in 50 ecm claim "
Dibutyl ether. The completely clear reaction mixture is 15 stirred for some time at room temperature and process for stabilizing organotin then carefully with the mixture of 12.5 ecm hydrides, characterized in that Dioxane and 12.5 ecm of water decomposed. The fancy that one can remove the instability Al (OH) _{3 is} removed by filtration and the resulting aluminum halogen compounds are sucked off Ether in a vacuum and the diphenyl-20 is distilled in a manner known per se by treatment with tin dihydride. little water or preferably sodium carbonate B e i s ρ i e 1 4 solutions removed. 100 g of triethyltin hydride, produced in known older patents considered: Way from triethyl tin chloride and diethyl aluminum- 35 German patent no. 1 117 577. 409 558/461 3.64 © Bundesdruckerei Berlin