Org. Synth. 1956, 36, 86
DOI: 10.15227/orgsyn.036.0086
TETRAETHYLTIN
[Tin, tetraethyl-]
Submitted by G. J. M. Van Der Kerk and J. G. A. Luijten
1.
Checked by M. S. Newman and L. L. Wood.
1. Procedure
A 2-l. three-necked flask is fitted with a reflux condenser (Note 1), a stirrer (Note 2), and a dropping funnel. The flask is suspended in a steam cone, which can also be used as a cooling bath. In the flask is placed 50 g. (2.05 g. atoms) of fine magnesium turnings (Note 3). In the dropping funnel is first introduced 5 ml. of a solution of 250 g. (175 ml., 2.3 moles) of ethyl bromide in 500 ml. of absolute ether. Three drops of bromine is mixed with the 5 ml., and the mixture is added to the magnesium. The Grignard reaction which starts at once (Note 4) is maintained by gradually adding the remainder of the ethyl bromide-ether solution. When the spontaneous reaction subsides, the mixture is heated gently under reflux with stirring for 30 minutes.
The flask is then cooled in ice, and in the course of about 20 minutes 83 g. of tin tetrachloride (37 ml., 0.32 mole) is added with vigorous stirring (Note 5). The mixture is heated at the reflux temperature for 1 hour, after which the condenser is set for distillation. During 1.5 hours the ether is removed by distillation while the flask is heated by an ample supply of steam (Note 6) and (Note 7).
The flask is again cooled in ice, the collected ether is returned to the reaction mixture, and the latter is decomposed by slowly adding first 85 ml. of ice water, then 400 ml. of ice-cold 10% hydrochloric acid. After stirring for some minutes, the contents of the flask are transferred to a separatory funnel. The layers are separated, and the ether layer is filtered through a folded filter and dried with calcium chloride (Note 8).
The ether is removed by distillation, and the crude tetraethyltin is distilled under water-pump vacuum, using a water bath for heating. The yield of tetraethyltin boiling at 63–65° /12 mm. is 67–72 g. (89–96%), n25D 1.4693–1.4699, d254 1.1916 (Note 9).
2. Notes
1.
A wide condenser must be employed to permit an ample reflux of
ether.
3.
The submitters have carried out this preparation on a three-fold scale with comparable yields.
4.
In general
bromine starts Grignard reactions more quickly than the usually employed
iodine.
5.
For adding the
tin tetrachloride it is advisable to use a dropping funnel which contains no
ether vapor, since the latter gives troublesome formation of solid etherate.
6.
The stirrer must be stopped at the beginning of the distillation or it will break, for the contents of the flask turn into a solid mass.
7.
Removal of the
ether is necessary to permit raising the reaction temperature. The temperature at the center of the mass reaches 60–65°. During the 1.5 hours of distillation, about
200 ml. of ether is collected, the remainder being firmly bound as etherates.
8.
To obtain a product free from traces of triethyltin halide the dried ethereal solution is treated with dry
ammonia, and the precipitate formed is removed by filtration.
9.
The submitters report that the same yields in terms of percentages are obtained if the procedure is applied to the preparation of
tetra-n-propyltin and
tetra-n-butyltin.
3. Discussion
Tetraethyltin has been prepared from
tin-sodium alloy and
ethyl iodide;
2 from
tin-sodium-zinc alloy and
ethyl bromide;
3,4 from
tin tetrachloride and
ethylmagnesium bromide;
5,6,7,8 or
triethylaluminum;
9 from
tin-magnesium alloy and
ethyl bromide or chloride;
10,11,12 and from
stannous chloride and
ethyllithium.
13 The method described is essentially that of Pfeiffer and Schnurmann.
5
This preparation is referenced from:
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
ethyl bromide or chloride
calcium chloride (10043-52-4)
hydrochloric acid (7647-01-0)
ammonia (7664-41-7)
ether (60-29-7)
magnesium,
magnesium turnings (7439-95-4)
bromine (7726-95-6)
Ethyl bromide (74-96-4)
stannous chloride
iodine (7553-56-2)
ethylmagnesium bromide (925-90-6)
tin tetrachloride (7646-78-8)
Ethyl iodide (75-03-6)
Tetraethyltin,
Tin, tetraethyl- (597-64-8)
tin-sodium
tin-sodium-zinc
triethylaluminum (97-93-8)
tin-magnesium
ethyllithium
tetra-n-propyltin (2176-98-9)
tetra-n-butyltin (1461-25-2)
Copyright © 1921-, Organic Syntheses, Inc. All Rights Reserved