3methyl1Hindole

3-methyl-1H-indole, commonly called 3-methylindole or skatole, is an aromatic heterocycle in the indole family. Its structure features a benzene ring fused to a five-membered nitrogen-containing pyrrole ring, with a methyl substituent at the 3-position. The formula is C9H9N and the molecular weight is about 131.17 g/mol.

Skatole has a strong, distinctive odor that is often described as fecal or animalic at higher concentrations. It occurs naturally in feces and in small amounts in some animal secretions and foods. The compound is formed in nature by bacterial metabolism of tryptophan in the gut and can also arise during the decomposition of organic matter. Because of its potent odor, skatole is notable in discussions of olfaction, animal waste, and fragrance science.

Synthesis and production of 3-methylindole can be achieved by methylation or directed alkylation at the C-3 position of indole using appropriate reagents; multiple synthetic routes are described in the chemical literature. In addition to laboratory synthesis, trace quantities can be produced as byproducts in processes involving tryptophan-containing materials.

In fragrance and flavor contexts, skatole is used in very small quantities to impart depth and animalic character to compositions, acting as a base or modifier note. Safety considerations for handling include standard precautions for volatile organic compounds: avoid inhalation of vapors and minimize skin or eye contact.