The invention provides compounds having the general formula I: and pharmaceutically acceptable salts thereof, wherein the variables R.sup.1, R.sup.2, R.sup.3, R.sup.4, subscipt m and n, have the meaning as described herein, and compositions containing such compounds and methods for using such compounds and compositions.

The invention provides compounds having the general formula I: and pharmaceutically acceptable salts thereof, wherein the variables R.sup.1, R.sup.2, R.sup.3, R.sup.4, subscipt m and n, have the meaning as described herein, and compositions containing such compounds and methods for using such compounds and compositions.

A process for the preparation of diaminophenothiazinium compounds is described, which allows achieving quickly and effectively a high degree of purity of the same.

A process for the preparation of diaminophenothiazinium compounds is described, which allows achieving quickly and effectively a high degree of purity of the same.

The present disclosure provides phenothiazine derivative compounds and salts thereof, compositions comprising these compounds, and methods of using these compounds in a variety of applications, such as treatment or suppression of diseases associated with decreased mitochondrial function resulting in diminished ATP production and/or oxidative stress and/or lipid peroxidation.

The present disclosure provides phenothiazine derivative compounds and salts thereof, compositions comprising these compounds, and methods of using these compounds in a variety of applications, such as treatment or suppression of diseases associated with decreased mitochondrial function resulting in diminished ATP production and/or oxidative stress and/or lipid peroxidation.

The present invention pertains generally to the field of chemical synthesis, and more particularly to methods for the chemical synthesis of a thiosulfonic acid of Formula (1) by a step of periodate mediated oxidative coupling of a thiosulfonic acid of Formula (2) with an aniline of Formula (3), as described herein. The present invention also relates to such methods which incorporate one or more additional (subsequent and/or preceding) steps, for example, to prepare compounds of Formula (5) from compounds of Formula (1); to prepare compounds of Formula (6) from compounds of Formula (5); and to prepare compounds of Formula (2) from compounds of Formula (4), as described herein.

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Disclosed are methods of synthesis and/or purification of certain 3,7-diamino-phenothiazin-5-ium compounds (diaminophenothiazinium compounds) including Methylthioninium Chloride (MTC) (Methylene Blue), and the resulting high purity characterized by a purity greater than 98%, and very low levels of heavy metals and organic impurities Azure A, B, C and MVB. Also disclosed are methods of treatment of a tauopathy or methemoglobinemia in a patient in need thereof, comprising administering to the patient a therapeutically effective amount of the high-purity diaminophenothiazinium compound.

Disclosed are methods of synthesis and/or purification of certain 3,7-diamino-phenothiazin-5-ium compounds (diaminophenothiazinium compounds) including Methylthioninium Chloride (MTC) (Methylene Blue), and the resulting high purity characterized by a purity greater than 98%, and very low levels of heavy metals and organic impurities Azure A, B, C and MVB. Also disclosed are methods of treatment of a tauopathy or methemoglobinemia in a patient in need thereof, comprising administering to the patient a therapeutically effective amount of the high-purity diaminophenothiazinium compound.

This disclosure pertains generally to the field of chemical synthesis and purification, and more specifically to methods of synthesizing and purifying certain 3,7 diamino-phenothiazin-5-ium compounds (referred to herein as diaminophenothiaziniumcompounds) 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). Also disclosed 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.