m-Crosol purple

meta-Cresol, also known as 3-methylphenol, is an organic compound with the chemical formula CH₃C₆H₄(OH). It is a colorless to pale yellow, viscous liquid with a characteristic phenolic odor. As an important industrial chemical, m-cresol is primarily used as an intermediate in the production of a variety of other compounds.
🏭⚗️ Production
m-Cresol is traditionally obtained from coal tar, a by-product of the coking process used in coal processing. Coal tar contains a mixture of phenol and its isomers, including cresols.
Industrial production methods include:
• The Cymene–Cresol Process: In this method, toluene is alkylated with propylene to form isomers of cymene, which are then oxidatively dealkylated, similar to the cumene process used in phenol production.
• Carbonylation Process: A mixture of methallyl chloride and acetylene is carbonylated in the presence of nickel carbonyl, producing m-cresol as a by-product.
🧪 Applications
m-Cresol is a versatile precursor in organic synthesis, used in the production of:
• Pesticides such as fenitrothion and fenthion
• Synthetic Vitamin E, through methylation to form 2,3,6-trimethylphenol
• Antiseptics, including amylmetacresol
• Solvents for Polymers: m-Cresol is particularly effective in casting conductive films of polyaniline, enhancing its electrical properties through a process known as secondary doping.
• Pharmaceutical Preservatives, such as in some insulin formulations
Natural Occurrence
m-Cresol naturally occurs in several biological and environmental contexts:
• It is found in the temporal gland secretions of male African elephants (Loxodonta africana) during musth.
• It is a constituent of tobacco smoke.
• It is released in defensive secretions by the ant Colobopsis saundersi during autothysis (self-sacrifice mechanism for colony defense).