This invention 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 "diaminophenothiazinium compounds") including Methylthioninium Chloride (MTC) (also known as Methylene Blue). In one embodiment, the method comprises the steps of, in order: a thiosulfonic acid formation (TSAF) as illustrated below, wherein the reaction is carried out in the presence of a thiosulfate and an oxidizing agent that is or comprises persulfate an oxidative coupling (OC); and a ring closure (RC). The resulting compounds and compositions comprising them (e.g., tablets, capsules) are useful in methods of medical treatment and diagnosis, etc., for example, tauopathies, or Alzheimer's disease (AD).
这项发明通常涉及
化学合成和纯化领域,更具体地涉及合成和纯化某些3,7-二
氨基苯并
噻嗪-5-ium化合物(以下简称为"二
氨基苯并
噻嗪化合物"),包括
氯化甲
硫蓝(
MTC)(又称
亚甲蓝)。在一种实施例中,该方法包括按顺序进行以下步骤:如下图所示的
硫代
磺酸形成(
TSAF)步骤,其中在
硫代
硫酸盐和氧化剂的存在下进行反应,该氧化剂是或包含过
硫酸盐;氧化偶联(OC);和环闭合(RC)。所得的化合物和包含它们的组合物(例如,片剂、胶囊)在医疗治疗和诊断等方法中具有用途,例如对于tau病变或阿尔茨海默病(AD)。