DE2648107B1 - Process for the preparation of diorganotin dihalides - Google Patents

Description

R ³

R ⁴

SnHaI,

(I)

R ¹

R ³

C = C

R ²

R ⁴

(Π)

The invention relates to a process for the preparation of certain diorganotin dihalides, which are an important Represent starting material for organotin stabilizers.

The known syntheses of diorganotin dihalides are based on reactions of tin halides with organometallic compounds of aluminum or magnesium, the Wurtz process, the Direct synthesis from organo halides and tin and hydrostannization.

According to a reaction in which it is assumed that the hydrostannation _{takes place via intermediate H 2} SnCb, diorganotin dihalides of the formula

(ROCOCH ₂ CH ₂ ) _{2 SnCl 2}

by converting tin, hydrochloric acid and carbonylactivated olefins in polar organic solvents obtained, and in certain cases the olefin itself can serve as a solvent.

However, the latter method has a number of disadvantages. So occur when using the olefin as a solvent, side reactions (polymerization) occur to a considerable extent. If you lead the reaction in polar organic solvents, e.g. B. ethers, through, is the desired after the reaction Product; depending on the type and amount of the solvent in whole or in part, together with all by-products in solution.

Accordingly, the cleaning operations and the isolation of the product can be very expensive will. Depending on the olefin used, products can arise that clump together in this way of working

10

20th

where R ¹ to R ^{4 have} the same meaning as in formula I, characterized in that the reaction is carried out in water at 10 ° to 50 ° C.

2. The method according to claim 1, characterized in that the reaction is carried out with the addition of a Carries out phase transfers.

35

40

45

50

55

60

65 tend. The recovery of the solvents by distillation is uneconomical.

All previously known hydrostannation of carbon-carbon double bonds proceed in the same way as this process exclusively in organic media (see e.g. W. P. N e u m a η η, Die org. Chemie of tin, Ferd. Enke-Verlag, Stuttgart 1967, chap. 9, DBP 12 14 237 and DT-OS 19 63 569).

The invention relates to a process for the preparation of diorganotin dihalides of the formula

in which R ¹ , R ² , R ³ and R ^{4 are} hydrogen or an alkyl group, where R ¹ and / or R ^{3 is} -CO-alkyl, -COOH, -COO-alkyl or -COCl, from tin, HCl and / or HBr and an olefin of the formula

R ¹

R ²

HC-C

R ³

R ⁴

-SnHaI ₂

in which R ¹ , R ² , R ³ and R ⁴ denote hydrogen or an alkyl group, where R ¹ and / or R ^{3 is} CO-alkyl, -COOH, -COO-alkyl or -COCl, from tin, HCL and / or HBr and an olefin of the formula

R ¹

C = C

R ²

R ⁴

which is characterized in that the reaction is carried out in water at 10-50 ° C.

It is surprising that, according to the invention, the hydrostannification can also be carried out in an aqueous medium leaves.

A further embodiment of the method according to the invention is characterized in that the Implementation carried out with the addition of a phase transfer.

Activated olefins of the formula II are, for. B. acrylic acids and their esters and halides and vinyl alkyl ketones.

The methyl, ethyl and butyl esters are preferred Acrylic, methacrylic and crotonic acids, acrylic acid chloride and methyl vinyl ketone.

In the process according to the invention for the preparation of the compound of the formula I, it is not necessary Use excess olefin as a solvent, so that polymerization and other disadvantages from the outset be avoided. If an excess of hydrohalic acid is used, it remains after the reaction has ended no olefin back. The desired product precipitates while the by-products are in excess as well Are hydrogen halide in the aqueous phase. The separation of the product is easy, z. B. by filtration or centrifugation, perform. Moisture residues can in the usual way, such as through Air drying or vacuum drying. So you get a pure and in most cases free-flowing product. The remaining water phase can with all the impurities it contains can be used several times after an appropriate concentration of hydrogen halide.

Another advantage of the process according to the invention is that the hydrogen halide acids need not be used as anhydrous gas, but can also be used as aqueous solutions are. The use of a phase transfer, such as tetrabutylammonium iodide, speeds up the reaction.

25th

30th

The compounds of the formula I prepared by the process according to the invention can be per se known way with mercaptocarboxylic acids and their esters, thioalcoholates, alkylcarboxylic acid salts, maleic acid salts, Maleic acid half-esters and their salts, xanthates, thiocarboxylic acids, dithiocarboxylic acids or convert alkali sulfides into stabilizers or stabilizer components for PVC (see e.g. A. K. Sawyer, Organotin Compounds, Vol. 2, 1971, pp. 297-508).

example 1

29.7 g (0.25 mol) of tin powder, 50 g (0.5 mol) of ethyl acrylate and 1 mol of HCl in the form of concentrated aqueous hydrochloric acid are at room temperature in Stirred in the presence of about 0.1 mol% tetrabutylammonium iodide as a phase transfer. After 3-4 hours the tin reacted without developing hydrogen. A white suspension is formed. This is via a Sucked off the frit, briefly pressed it onto filter paper and dried at about 80 Torr. The white one that is easy to spread Powder has the following analytical data (values calculated in brackets for

(C ₂ H ₅ OCOCH ₂ CHz) ₂ SnCl ₂ ):

C: 31.23 (30.65)%; H: 4.74 (4.63)%; Cl: 19.02 (18.10)%; Sn: 30.85 (30.29)%.

The melting point is 83-85 ° C, the IR spectrum is identical to a product, which from ethereal Solution represented by means of gaseous hydrochloric acid and has been recrystallized several times. Yield 70g.

Example 2

The residual aqueous phase from Example 1 is restored to its original state with gaseous HCl Brought hydrochloric acid content and again with 29.9 g (0.25. Mol) coarser tin (grain size about 1 mm) and 50 g (0.5 mol) of ethyl acrylate reacted under otherwise identical conditions. Result as in example 1.

Example 3

29.7 g (0.25 mol) of tin powder, 50 g (0.5 mol) of ethyl acrylate and 172 g (1 mol) of 47% HBr are at room temperature (approx. 20 ^° C.) and atmospheric pressure in the presence of 0.1 Mol% tetrabutylammonium iodide stirred.

After 5-8 hours the tin has reacted without evolution of hydrogen. The light-colored suspension will be over filtered through a suction filter. The filtrate consists only of an aqueous phase. The IR spectrum of the filtered off crystalline product in the range between 625 and 4000 wave numbers is similar to that of the

(C ₂ H ₅ OCO -CH ₂ CH ₂ -I ₂ SnCl ₂ .

The melting range is 94-100 ° C. Yield 90 g. The elemental analysis shows the following values; values calculated in brackets for

(C ₂ H ₅ OCO - CH ₂ CH ₂ J ₂ SnBr ₂ :

C 24.28 (24.97)%; H 3.66 (3.74)%; Sn 24.65 (24.70)%; Br 33.41 (33.25)%.

Example 4

To a mixture of 39.2 g (0.1 mol) (C ₂ H ₅ OCOCH ₂ CH ₂ ) 2SnCl ₂

and 18.6 g (0.2 mol) of aniline in 100 ml of a hydrocarbon mixture the boiling point 80-110 ° C one drips

60

65 40.8 g (0.2 mol) isooctyl thioglycolate. After heating to about 85 ° C. for one hour, the mixture is allowed to cool and the aniline hydrochloride is filtered off. The filtrate is washed with water and freed from solvent by vacuum distillation. 697 g are obtained

(C ₂ H ₅ OCOCH ₂ CH ₂ ) ₂ Sn (SCH ₂ COO - i - C ₈ Hi ₇ ) ₂
as a residue.

Example 5

29.7 g (0.25 mol) tin powder, 43 g (0.5 mol) acrylic acid methyl ester and 1 mole of HCl in the form of concentrated aqueous hydrochloric acid are at room temperature touched. Approx. 0.1 mol of tetrabutylammonium iodide serves as phase transfer. After about 3 hours one will form light gray suspension that brightens to white after an additional hour.

It is then suctioned off through a frit and the solid is dried at about 80 torr. The filtrate consists only of an aqueous phase. The melting point of the white, free-flowing powder is 130 to 133 ° C. The Analysis data show the following result (values calculated in brackets for

(CH ₃ OCOCH ₂ CH ₂ ) ₂ SnCl ₂ ):

C: 25.55 (26.39)%
H: 4.03 (3.85)%
Cl: 20.52 (19.52)%
Sn: 33.20 (32.64)%

Yield: 56 g.

Example 6

29.7 g (0.25 mol) of tin powder, 64 g (0.5 mol) of isobutyl acrylate and 101 g (1 mol) of 36% strength aqueous hydrochloric acid are in the presence of about 0.1 mol% of tetrabutylammonium iodide at room temperature touched. The tin has reacted after stirring for about 12 hours. A crystalline one is isolated white solid which, after drying at approx. 80 torr and room temperature, melts at 45 to 50 ° C. That so received

(iso - C ₄ H ₉ OCOCH ₂ CH ₂ ) ₂ SnCl ₂

shows the following analysis data (values calculated in brackets for

(iso - C4H ₉ OCOCH ₂ CH ₂ ) ₂ SnCl2):

C: 37.56 (37.52)%
H: 5.79 (5.81)%
Cl: 16.76 (15.86)%
Sn: 26.25 (26.51)%

Yield: 70 g.

Example 7

11.9 g (0.1 mol) of tin powder, 20 g (0.2 mol) of ethyl acrylate and 0.4 mol of HCl in the form aqueous, concentrated hydrochloric acid are stirred at room temperature. Triethanolamine in the amount of approx. 5 mol% serves as phase transfer. The tin has reacted after 3 to 4 hours; you get a white one Suspension. The white solid is separated off by suction through a frit. The yield at

(C ₂ H ₂ OCOCH ₂ CH ₂ ) ₂ SnCl ₂
after drying is approx. 69%.

5

Example 8 A clear, oily liquid remains as the residue

59.4 g (0.5 mol) tin powder, 128 g (IMol) acrylic acid (yield 67%). This shows the following analysis data (in

n-butyl ester and 2 mol of HCl in the form of aqueous, brackets calculated values for

concentrated hydrochloric acid in the presence of approx., _{n u} ^^^^ u ^

0.1 mol% tetrabutylammonium iodide ^{as phase transfer 5 (n} "UH _{9 OCOCH 2} C

fer stirred at room temperature. After 12 hours C: 38.7 (37.52)%

The tin has dissolved by stirring. There are 2 phases .. - H: 6.08 (5.81)%

before, of which the organic in the rotary evaporator .- Ch. 16.23 (15.86)% ■ '

is freed from slight volatile impurities. ^ Sn: 25.32 (26.51)%.

Claims (1)

Patent claims: 1. Process for the preparation of diorganotin dihalides of the formula R ¹ R ² HC-C-