Method for the preparation of pure carboxyethyl germanium sesquioxide

Abstract

A synthetic method for generating pure carboxyethyl germanium sesquioxide in the absence of toxic impurities. In the method germanium dioxide and metallic germanium are not used as starting materials. The method involves steps which ensure (a) absence of any residual germanium tetrachloride to ensure none is available to form germanium dioxide, (b) removal of any germanium dioxide, (c) removal of any germanium tetrachloride later produced from any germanium dioxide and (d) final removal of any germanium dioxide. In an alternative method, intermediate TPA is prepared by direct precipitation from a concentrated solution with a halogenated solvent preferably dichloromethane when poured into a non-polar alkyl solvent preferably hexane at ambient temperature and then converted to carboxyethyl germanium sesquioxide.

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