Trimethyltin chloride

Trimethyltin chloride is an organotin compound with the formula (CH3)3SnCl. It is a white solid that is highly toxic and malodorous. It is susceptible to hydrolysis.

Synthesis
Trimethyltin chloride can be prepared by the redistribution reaction of tetramethyltin with tin tetrachloride.
 * SnCl4 + 3 Sn(CH3)4 → 4 (CH3)3SnCl

This redistribution reaction is typically performed with no solvent because high temperatures are required and purification is simplified.

A second route to (CH3)3SnCl involves treating the corresponding hydroxide or oxide (in the following reaction, trimethyltin hydroxide (CH3)3SnOH) with a halogenating agent such as hydrogen chloride or thionyl chloride (SOCl2):
 * (CH3)3SnOH + HCl → (CH3)3SnCl + H2O

Uses
Trimethyltin chloride is used as a source of the trimethylstannyl group ((CH3)3Sn\s). For example, it is a precursor to vinyltrimethylstannane ((CH3)3SnCH\dCH2) and indenyltrimethylstanane (CH3)3SnC9H7 (see Transition metal indenyl complex):
 * CH2\dCHMgBr + (CH3)3SnCl → (CH3)3SnCH\dCH2 + MgBrCl
 * LiC9H7 + (CH3)3SnCl → (CH3)3SnC9H7 + LiCl

An example of an organolithium reagent reacting with (CH3)3SnCl to form a tin-carbon bond is:
 * LiCH(Si(CH3)3)(Ge(CH3)3) + (CH3)3SnCl → (CH3)3SnCH(Si(CH3)3)(Ge(CH3)3) + LiCl

Organotin compounds derived from Me3SnCl are useful in organic synthesis, especially in radical chain reactions. (CH3)3SnCl is a precursor to compounds used in PVC stabilization. Reduction of trimethyltin chloride with sodium gives hexamethylditin:
 * 2 Na + 2 (CH3)3SnCl → (CH3)3Sn\sSn(CH3)3 + 2 NaCl