Investigation of the homogeneous destructive hydrogenation of butylphenols under hydrogen pressure

Summary

• 1. Homogeneous destructive hydrogenation of three isomeric butylphenols at 440° and high hydrogen pressures was investigated. The reaction rate decreased in the series o-n-butylphenol> p-n-butylphenol>p-sec-butylphenol. The difference in the rate of total conversion was determined predominantly by the stage in which there was thermal cleavage of the weakest bond of the alkyl group.

• 2. A rise in hydrogen pressure accelerated the process of homogeneous destructive hydrogenation of butylphenols.

• 3. The weakest bonds in n-butylphenols were apparently the β and γ C-C bonds in the alkyl chain; the same was true also for para sec-butylphenol.

• 4. Comparison of the results obtained led to the conclusion that depending on the increase in the number of carbon atoms in the side chain of the alkylphenol, thermal decomposition processes start to prevail to a greater extent over reactions leading to cleavage of the entire alkyl radical from the aromatic nucleus.