Isobutylbenzene is an organic chemical compound with the chemical formula C${10}$H${14}$. It is an aromatic hydrocarbon, consisting of a benzene ring substituted with an isobutyl group. It is primarily known for its role as a key intermediate in the synthesis of various pharmaceutical compounds, most notably ibuprofen.
Properties
- Chemical Formula: C${10}$H${14}$
- Molar Mass: 134.22 g/mol
- Appearance: Colorless liquid
- Density: 0.853 g/mL (at 25 °C)
- Boiling Point: 171-172 °C (340-342 °F)
- Melting Point: -51 °C (-60 °F)
- Solubility: Insoluble in water; soluble in organic solvents such as ethanol, diethyl ether, and benzene.
- CAS Number: 538-93-2
Isobutylbenzene is a volatile organic compound (VOC) with a characteristic aromatic odor. Its structure features a benzene ring directly attached to an isobutyl group, which is a branched four-carbon alkyl chain.
Synthesis
Isobutylbenzene can be synthesized through several methods, including:- Friedel-Crafts Alkylation: This is a common industrial method where benzene reacts with isobutyl chloride (or isobutyl alcohol in the presence of an acid catalyst) using a Lewis acid catalyst like aluminum chloride (AlCl$_3$).
- Reduction of Isobutyrophenone: The carbonyl group of isobutyrophenone can be reduced to a methylene group, for example, using a Wolff-Kishner reduction or a Clemmensen reduction.
Uses
The primary and most significant application of isobutylbenzene is as a crucial intermediate in the industrial synthesis of ibuprofen (isobutylphenylpropanoic acid), a widely used nonsteroidal anti-inflammatory drug (NSAID). The synthesis of ibuprofen typically involves the acylation of isobutylbenzene, followed by subsequent reactions to introduce the propanoic acid side chain.Besides its role in ibuprofen synthesis, isobutylbenzene may also be used:
- As a general intermediate in organic synthesis for creating other substituted aromatic compounds.
- As a research chemical in academic and industrial laboratories.