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This latter cumene converts into cumene radical and feeds back into subsequent chain formations of cumene hydroperoxides. A pressure of 5 atm is used to ensure that the unstable peroxide is kept in liquid state. Cumene hydroperoxide undergoes a rearrangement reaction in an acidic medium (the Hock rearrangement) to give phenol and acetone. In ...
The oxidation of 2,4,6-tri-tert-butylphenol in the alkaline to the intensely blue-colored phenoxy radical can also occur with potassium ferricyanide. [1] [9] [6] The 2,4,6-tri-tert-butylphenoxy radical forms blue crystals on cooling to -70 °C which are stable at room temperature for several weeks and only gradually turn yellow. [9]
Acetophenone is formed as a byproduct of the cumene process, the industrial route for the synthesis of phenol and acetone.In the Hock rearrangement of isopropylbenzene hydroperoxide, migration of a methyl group rather than the phenyl group gives acetophenone and methanol as a result of an alternate rearrangement of the intermediate:
Cumene (isopropylbenzene) is an organic compound that contains a benzene ring with an isopropyl substituent. It is a constituent of crude oil and refined fuels. It is a flammable colorless liquid that has a boiling point of 152 °C.
Cumene hydroperoxide is the organic compound with the formula C 6 H 5 C(CH 3) 2 OOH; this oily liquid is classified as an organic hydroperoxide. [2] Products of decomposition of cumene hydroperoxide are methylstyrene, acetophenone, and 2-phenylpropan-2-ol. [3] It is produced by treatment of cumene with oxygen, an autoxidation.
After removal of the cancer, closure of the skin for patients with a decreased amount of skin laxity involves a split-thickness skin graft. A donor site is chosen and enough skin is removed so that the donor site can heal on its own. Only the epidermis and a partial amount of dermis is taken from the donor site which allows the donor site to heal.
Hydroquinone is used as a topical application in skin whitening to reduce the color of skin. It does not have the same predisposition to cause dermatitis as metol does. This is a prescription-only ingredient in some countries, including the member states of the European Union under Directives 76/768/EEC:1976. [23] [24]
Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer occurring in about three people per million members of the population. [1] It is also known as cutaneous APUDoma, primary neuroendocrine carcinoma of the skin, primary small cell carcinoma of the skin, and trabecular carcinoma of the skin. [2]