2,4-Di-tert-butylphenol (2,4-DTBP) is a white solid with a phenolic odour. It is primarily used as a raw material for the production of several commercially important antioxidants and phenolic benzotriazole-type UV absorbers. It also finds use as a starting material in the synthesis of agrochemicals, fragrances and catalysts (i.e. Jacobsen's catalyst).
The butylation of phenol is typically achieved by a Friedel-Crafts alkylation with isobutylene catalysed by a strong acid. These acids can be either liquids like triflic acid, or solid acids such as zeolites. The isobutylene can be generated in situ by the dehydration of tert-butyl alcohol or methyl tert-butyl ether, which being liquids are simpler to handle than the highly flammable isobutylene gas.[1]
2,4-DTBP is used in the production of antioxidants like tris(2,4-di-tert-butylphenyl)phosphite.