End-to-end continuous flow synthesis and purification of diphenhydramine hydrochloride featuring atom economy, in-line separation, and flow of molten ammonium salts

A continuous end-to-end synthesis and purification of diphenhydramine hydrochloride featuring atom economy and waste minimization is described. Combining a 1 : 1 molar ratio of the two starting material streams (chlorodiphenylmethane and N,N-dimethylaminoethanol) in the absence of additional solvent...

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Bibliographic Details
Main Authors: Snead, David R., Jamison, Timothy F.
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Language:en_US
Published: Royal Society of Chemistry 2014
Online Access:http://hdl.handle.net/1721.1/87078
https://orcid.org/0000-0002-8601-7799
Description
Summary:A continuous end-to-end synthesis and purification of diphenhydramine hydrochloride featuring atom economy and waste minimization is described. Combining a 1 : 1 molar ratio of the two starting material streams (chlorodiphenylmethane and N,N-dimethylaminoethanol) in the absence of additional solvent at high temperature gives the target compound directly as a molten salt (ionic liquid above 168 °C) in high yield. This represents the first example of continuous active pharmaceutical ingredient (API) production in this manner. Six of the twelve principles of green chemistry as defined by the American Chemical Society are achieved, most prominently waste minimization and atom economy.