cymene

Cymene is the common name for any of three isomeric methyl isopropylbenzenes with the molecular formula C10H14. The isomers are o-cymene (1-methyl-2-(propan-2-yl)benzene), m-cymene (1-methyl-3-(propan-2-yl)benzene), and p-cymene (1-methyl-4-(propan-2-yl)benzene). Each consists of a benzene ring bearing a methyl group and an isopropyl group in different relative positions.

Natural occurrence and production: Cymenes occur in trace amounts in various plant essential oils, with p-cymene being a common constituent of cumin and thyme oils. They are also produced synthetically and sold as isomeric mixtures or as individual isomers for industrial use and research. In industry, cymenes may be separated into the distinct isomers through distillation and other purification steps.

Physical and chemical properties: Cymenes are colorless to pale-yellow liquids at room temperature and have an aromatic odor. They are insoluble in water and soluble in organic solvents. They are flammable and should be stored away from heat sources and oxidizers. As aromatic hydrocarbons, they can undergo typical reactions of alkylbenzenes, such as electrophilic substitution, and can be used as precursors in the synthesis of other fragrance or flavor compounds.

Applications and safety: In addition to their role as fragrance and flavor ingredients, cymenes serve as chemical intermediates in the synthesis of various intermediates and aroma compounds. They should be handled with standard hydrocarbon safety precautions to avoid inhalation, skin contact, or fire hazards.