Process for recovery of organotin esters from reaction mixtures containing the same and re-use of the recovered organotin compounds

Abstract

A process which comprises extracting 1,3-diacyloxy-1,1,3,3-tetra(hydrocarbyl) distannoxane from a mixture containing 1,3-diacyloxy-1,1,3,3-tetra(hydrocarbyl)distannoxane, a sucrose-6-ester, and polar aprotic solvent, which process comprises the steps of: (a) contacting said mixture, in the presence of a small amount of water, with an organic solvent that is substantially immiscible with water to form thereby an extraction mixture, wherein the amount of water employed is sufficient to cause efficient partitioning of said 1,3-diacyloxy-1,1,3,3-tetra(hydrocarbyl)distannoxane from a first phase comprising said polar aprotic solvent into second phase comprising said organic solvent; (b) agitating the extraction mixture for a period of time and at a temperature sufficient to form thereby a two-phase mixture wherein the preponderance of the 1,3-diacyloxy-1,1,3,3-tetra(hydrocabyl)distannoxane in the extraction mixture is contained in said second phase and essentially all of the sucrose-6-ester in the extraction mixture is contained in said first phase; and (c) separating said first phase from said second phase.

Dependencies are inferred from the claim text.