Acetophenone

Acetophenone is the organic compound with the formula C6H5C(O)CH3 (also represented by the pseudoelement symbols PhAc or BzMe). It is the simplest aromatic ketone. This colorless, viscous liquid is a precursor to useful resins and fragrances. Acetophenone is the organic compound with the formula C6H5C(O)CH3 (also represented by the pseudoelement symbols PhAc or BzMe). It is the simplest aromatic ketone. This colorless, viscous liquid is a precursor to useful resins and fragrances. Acetophenone is recovered as a by-product of the oxidation of ethylbenzene to ethylbenzene hydroperoxide. Ethylbenzene hydroperoxide is an intermediate in the commercial production of propylene oxide via the propylene oxide - styrene co-product process. Ethylbenzene hydroperoxide is primarily converted to 1-phenylethanol (α-methylbenzyl alcohol) in the process with a small amount of by-product acetophenone. Acetophenone is recovered or hydrogenated to 1-phenylethanol which is then dehydrated to produce styrene. Commercially significant resins are produced from treatment of acetophenone with formaldehyde and a base. The resulting copolymers are conventionally described with the formula n, resulting from aldol condensation. These substances are components of coatings and inks. Modified acetophenone-formaldehyde resins are produced by the hydrogenation of the aforementioned ketone-containing resins. The resulting polyol can be further crosslinked with diisocyanates. The modified resins are found in coatings, inks and adhesives. Acetophenone is an ingredient in fragrances that resemble almond, cherry, honeysuckle, jasmine, and strawberry. It is used in chewing gum. It is also listed as an approved excipient by the U.S. FDA. In instructional laboratories, acetophenone is converted to styrene in a two-step process that illustrates the reduction of carbonyls using hydride and the dehydration of alcohols: A similar two-step process is used industrially, but reduction step is performed by hydrogenation over a copper catalyst. Being prochiral, acetophenone is also a popular test substrate for asymmetric hydrogenation experiments. Acetophenone is used for the synthesis of many pharmaceuticals. A Mannich reaction with dimethylamine and formaldehyde gives β-dimethylaminopropiophenone. Using diethylamine instead gives the diethylamino analog.