a higher moleculsr weight alcohol containing from 12 to 20 carbon atoms as the alcohol component of the aforementioned ester r 39 coor 34 in this instance the alcohol r 34 oh would not be removed during the transesterification but rather is isolated together with the final organotin product the alcohol serves as a lubricant or processing acid in the stabilized halogenated polymer composition once the acid or ester has been added the aqueous phase of the reaction mixture is removed and discarded following removal of the aqueous phase the reaction mixture is heated to 100 u00b0 180 u00b0 c to effect the esterification or transesterification reaction if the by product is water or a volatile alcohol boiling below about 120 u00b0 c the by product is continuously removed during the reaction using a suitable distillation apparatus to minimize overheating and the accompanying product decomposition the final portion of water is preferably removed under a reduced pressure that is usually equivalent to 10 100 mm of mercury once all of the water or alcohol has been removed the final liquid organotin compound remains in the reaction vessel it may be necessary to filter the product to remove small amounts of solid materials the products obtained using the present method are useful for the same applications as other mono and diorganotin compounds containing tin sulfur bonds the present compounds are particularly effective heat stabilizers for vinyl chloride polymers and other high molecular weight halogen containing polymers the compounds are conventionally employed for this purpose at concentrations of from 0 1 to 10 by weight organotin derivatives of mercaptoalcohol esters may also find use as antioxidants for a variety of materials the following examples demonstrate preferred embodiments of the present method and as such.