- NOVEL IMPROVED METHOD FOR SYNTHESIZING DIAMINOPHENOTHIAZINE COMPOUNDS
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The present invention relates to chemical synthesis and purification. Specifically, the present invention relates to a novel and improved method of synthesizing high purity diaminophenothiazine compounds of Formula I, specifically Methylene Blue and its pharmaceutically acceptable salt or hydrates thereof. The present invention relates to an improved method of synthesizing Methylene Blue compound of higher purities than those achievable by using known methods of synthesis as per the requirements of the international pharmacopoeias like USP and EP.
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Paragraph 00212-00213
(2020/12/30)
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- A preparation method of methylene blue
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The invention discloses a preparation method of methylene blue, and belongs to the technical field of intermediate synthesis in fine chemical engineering. The preparation method comprises the following steps: in a condensed hydrochloric acid solution, carrying out nitrosation reactions between sodium nitrite and N,N-dimethylaniline so as to obtain an intermediate namely p-nitroso-N,N-dimethylaniline; subjecting p-nitroso-N,N-dimethylaniline to hydrogenation reduction to prepare p-amino-N,N-dimethylaniline; oxidizing p-amino-N,N-dimethylaniline, then adding sodium thiosulfate to carry out addition reactions to prepare 2-amino-5-dimethylaminophenyl thiosulfonic acid, adding N,N-dimethylaniline into 2-amino-5-dimethylaminophenyl thiosulfonic acid to carry out oxidative condensation reactions to generate bis(4-dimethylaminophenyl) thiosulfonic acid; and making bis(4-dimethylaminophenyl) thiosulfonic acid carry out ring-closing reactions to obtain methylene blue. The provided preparation method has the advantages of high product purity, simple technology flow, low manufacture cost, suitability for industrial production, easily-available raw materials, and little pollution to the environment.
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Paragraph 0015; 0031; 0047; 0063; 0064; 0074; 0075; 0085
(2018/04/02)
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- SYNTHESIS OF A THIOSULFONIC ACID BY A STEP OF PERIODATE MEDIATED OXIDATIVE COUPLING OF A THIOSULFONIC ACID WITH AN ANILINE
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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 For
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Page/Page column 39; 40
(2018/07/29)
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- METHODS OF CHEMICAL SYNTHESIS OF DIAMINOPHENOTHIAZINIUM COMPOUNDS INCLUDING METHYLTHIONINIUM CHLORIDE (MTC)
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Methods of synthesizing and purifying certain 3,7-diamino-phenothiazin-5-ium compounds (referred to herein as "diaminophenothiazinium compounds") including Methythioninium Chloride (MTC) (also known as Methylene Blue) are provided.
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- METHODS OF CHEMICAL SYNTHESIS OF DIAMINOPHENOTHIAZINIUM COMPOUNDS INVOLVING THE USE OF PERSULFATE OXIDANTS
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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 compound
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Page/Page column 59
(2010/12/17)
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- METHODS OF CHEMICAL SYNTHESIS AND PURIFICATION OF DIAMINOPHENOTHIAZINIUM COMPOUNDS INCLUDING METHYLTHIONINIUM CHLORIDE (MTC)
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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 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.
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Page/Page column 68-75
(2010/10/20)
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