Triorganotin oxides, preparation

Organotin alkoxides and phenoxides can be prepared from the reaction of an alkali metal alkoxide or phenoxide with the appropriate organotin halide. Triorganotin alkoxides and phenoxides are available from the reaction of bis(triorganotin) oxides with alcohols or phenols or the corresponding carbonates, and the amides R Sn(NR"2)4 react with alcohols to give the corresponding alkoxides. 

Triorganotin hydroxides and oxides are usually prepared by the hydrolysis of the corresponding chlorides under alkaline conditions. A recent patent reports the formation of trialkyl-, dialkyl-, and monoalkyl-tin oxides by passing an alcohol in the gas phase over tin powder in the presence of a Lewis acid at 200-400 °C,9 for example ... 

Branching at the a-carbon atom appears to confer enough steric hindrance to inhibit dehydration of the hydroxide. Tricyclohexyltin hydroxide, which is used as an acaricide under the name of Plictran, is stable up to about 125 °C when it loses water to give the oxide.3 Tri-t-butyltin hydroxide can be prepared from tris(di-t-butyltin oxide) as shown in Scheme 12-1, and loses water to give bis(tri-t-butyltin) oxide only when it is heated for several horns under vacuum at 200 °C. The properties of some triorganotin hydroxides and oxides are given in Table 12-1.15... 

The sodium halide which is formed in these reactions is very finely divided, and may be difficult to filter off.2 A more convenient way of preparing the triorganotin alkoxides and phenoxides is by the azeotropic dehydration of a mixture of the bis(trialkyltin) oxide and alcohol or phenol in a solvent such as benzene or toluene.4... 

The triorganotin mixed oxides sxjmmarized in Table I8I are prepared by methods from the following scheme. 

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