Methods of chemical synthesis and purification of diaminophenothiazinium compounds including methylthioninium chloride (MTC): methods of treatment of a tauopathy condition comprising the use of thioninium compounds

Claude Michel Wischik (Inventor), Janet Elizabeth Rickard (Inventor), Charles Robert Harrington (Inventor), David Horsley (Inventor), John Mervyn David Storey (Inventor), Colin Marshall (Inventor), James Peter Sinclair (Inventor)

Research output: Patent


This invention pertains generally to the field of chemical synthesis and purification, and more specifically to methods of synthesizing and purifying certain 3,7-diaminophenothiazin-5-ium compounds (referred to herein as "diaminophenothiazinium compounds") including Methythioninium Chloride (MTC) (also known as Methylene Blue). In one embodiment, the method comprises the steps of, in order: nitrosylation (NOS); nitrosyl reduction (NR); thiosulfonic acid formation (TSAF); oxidative coupling (OC); Cr(VI) reduction (CR); isolation and purification of zwitterionic intermediate (IAPOZI); ring closure (RC); chloride salt formation (CSF); one of: sulphide treatment (ST); dimethyldithiocarbamate treatment (DT); carbonate treatment (CT); ethylenediaminetetraacetic acid treatment (EDTAT); organic extraction (OE); and recrystallisation (RX). The present invention also pertains to the resulting (high purity) compounds, compositions comprising them (e.g., tablets, capsules), and their use in methods of inactivating pathogens, and methods of medical treatment and diagnosis, etc., for example, for tauopathies, Alzheimer's disease (AD), skin cancer, melanoma, viral diseases, bacterial diseases, or protozoal diseases.
Original languageEnglish
Patent numberUS7,737,138
Publication statusPublished - 15 Jun 2010


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