A low-cost method for preparing 2-chloro-5-(β-D-glucopyranoglucose-1-yl)-4'-ethoxydiphenylmethane

Abstract

This invention discloses a low-cost method for preparing 2-chloropyranose-1-yl)-4''-ethoxydiphenylmethane, belonging to the field of pharmaceutical synthesis technology. The method uses a hemiacetal compound of formula I as a substrate, and in an organic solvent, under the action of a heterogeneous solid acid catalyst with a water content of less than 2.0% and polymethylhydrosiloxane with specific parameters, a reduction reaction occurs at -20°C to 25°C, highly selectively preparing the compound of configuration II. This invention ingeniously utilizes the spatial confinement effect formed by the matching of the micropores of the dehydrated solid acid and the macromolecular reducing agent, achieving a breakthrough increase in the diastereomeric excess percentage of the target product to an extremely high level. Simultaneously, it completely eliminates the constraints of the traditional -78°C cryogenic conditions, significantly reducing reagent costs. The catalyst can be easily recovered and reused through solid-liquid separation, and no fluorine- or boron-containing waste liquid is generated, making it highly promising for industrial application.

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