4-Isopropenylphenol Explained

4-Isopropenylphenol is an organic compound with the formula . The molecule consists of a 2-propenyl group (CH₂=C-CH₃) affixed to the 4 position of phenol. The compound is an intermediate in the production of bisphenol A (BPA), 2.7 Mkg/y of which are produced annually (2007). It is also generated by the recycling of o,p-BPA, a byproduct of the production of the p,p-isomer of BPA.^[1]

Synthesis and reactions

The high-temperature hydrolysis of BPA gives the title compound together with phenol:^[2]

The compound can also be produced by catalytic dehydrogenation of 4-isopropylphenol.^[3]

4-Isopropenylphenol undergoes O-protonation by sulfuric acid, giving the carbocation, which undergoes a variety of dimerization reactions.^[4]

References

1. 10.1021/ie030429+. 2004 . 43 . 5 . de Angelis . A. . Ingallina . P. . Perego . C. . Solid Acid Catalysts for Industrial Condensations of Ketones and Aldehydes with Aromatics . Industrial & Engineering Chemistry Research .
2. 10.1039/b313509h. Synthesis of p-isopropenylphenol in high-temperature water . 2004 . Hunter . Shawn E. . Felczak . Claire A. . Savage . Phillip E. . Green Chemistry . 6 . 4 . 222 .
3. 10.1021/jo01098a012. Preparation of Vinylphenols and Isopropenylphenols . 1958 . Corson . B. B. . Heintzelman . W. J. . Schwartzman . L. H. . Tiefenthal . H. E. . Lokken . R. J. . Nickels . J. E. . Atwood . G. R. . Pavlik . F. J. . The Journal of Organic Chemistry . 23 . 4 . 544–549 .
4. 10.1021/ol0493305. Generation and Synthetic Uses of Stable 4-[2-Isopropylidene]-phenol Carbocation from Bisphenol A . 2004 . Chen . Wei-Fu . Lin . Hsing-Yo . Dai . Shenghong A. . Organic Letters . 6 . 14 . 2341–2343 . 15228274 .