Methyl violet 6B
Methyl violet 6B (Pentamethylparosanilinium chloride, 4-[[4-(dimethylamino)phenyl]-(4-methyliminocyclohexa-2,5-dien-1-ylidene)methyl]-N,N-dimethylaniline hydrochloride) is a violet triarylmethane dye from the group of cationic dyes and an essential component of C.I. Basic Violet 1 (trivial name methyl violet). The compound is sometimes equated with methyl violet in the literature. Methyl violets are mixtures of tetramethyl (2B), pentamethyl (6B) and hexamethyl (10B) pararosanilins.[2] SynthesisTo produce methyl violet 6B, N,N-dimethylaniline is oxidized with atmospheric oxygen and copper sulfate as a catalyst, using phenol and large amounts of salt as a diluent. The central carbon atom of the dye is provided by the oxidation of a methyl group of N,N-dimethylaniline to formaldehyde.[3] In this process, a reaction product is obtained that contains the tetra- to hexamethylated compounds in addition to the pentamethylated compound. References
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