Бензофенон

Химические свойства

Benzophenone is a combustible, white, crystalline solid with a rose-like odor. soluble in ethanol, ether, chloroform and other organic solvents and monomers, insoluble in water. It is a free radical photoinitiator, mainly used in free radical UV curing systems, such as coatings, inks, adhesives, etc. It can be prepared in several ways, for example, by Friedel–Crafts reaction of benzene and benzoyl chloride with aluminum chloride, or of benzene and carbon tetrachloride, and oxidation of diphenylmethane.

Вхождение

Benzophenone has been found in various fruits, including Vitis vinifera L., black tea, cherimoya (Annona cherimola), mountain papaya (Carica pubescens), and soursop (Annona muricata L.).

Использование

Benzophenone is used as a synthetic intermediate for manufacture of pharmaceuticals and agricultural chemicals. It is also used as a photoinitiator in UV-curable printing inks, as a fragrance in perfumes, as a flavor enhancer in foods. Benzophenone can be added as a UV-absorbing agent to plastics, lacquers, and coatings at concentrations of 2–8%.

Определение

ChEBI: Benzophenone is the simplest member of the class of benzophenones, being formaldehyde in which both hydrogens are replaced by phenyl groups. It has a role as a photosensitizing agent and a plant metabolite.

Методы производства

Benzophenone is commercially synthesized by the atmospheric oxidation of diphenylmethane using a catalyst of copper naphthenate. Alternatively, it can be produced by a Friedel–Crafts acylation of benzene using either benzoyl chloride or phosgene in the presence of aluminum chloride .

Общее описание

Benzophenone(119-61-9) appears as white solid with a flowery odor. May float or sink in water. It is a widely used building block in organic chemistry, being the parent diarylketone.

Реакции воздуха и воды

Insoluble in water.

Профиль реактивности

Ketones, such as Benzophenone, are reactive with many acids and bases liberating heat and flammable gases (e.g., H2). The amount of heat may be sufficient to start a fire in the unreacted portion of the ketone. Ketones react with reducing agents such as hydrides, alkali metals, and nitrides to produce flammable gas (H2) and heat. Ketones are incompatible with isocyanates, aldehydes, cyanides, peroxides, and anhydrides. They react violently with aldehydes, HNO3, HNO3 + H2O2, and HClO4. Benzophenone can react with oxidizing materials.

Угроза здоровью

Ingestion causes gastrointestinal disturbances. Contact causes eye irritation and, if prolonged, irritation of skin.

Пожароопасность

Flash point data for Benzophenone are not available, but Benzophenone is probably combustible.

Контактные аллергены

Unsubstituted benzophenone is largely used in chemical applications. It acts as a marker for photoallergy to ketoprofen.

Профиль безопасности

Moderately toxic by ingestion andintraperitoneal routes. Combustible when heated.Incompatible with oxidizers. When heated todecomposition it emits acrid and irritating fumes.

Возможный контакт

Benzophenone is used in UV curing of inks and coatings; as an intermediate; as an odor fixative in fragrances, flavoring, soaps; in the manufacture of pharmaceuticals and insecticides; in organic syntheses.

Канцерогенность

Lifetime dermal carcinogenicity studies in mice and rabbits did not show any tumor excess in the treated animals. Female Swiss mice and New Zealand White rabbits of both sexes were treated dermally with 0, 5, 25, or 50% of benzophenone (0.02 mL) twice a week for 120 or 180 weeks. Weekly examination of the rabbits did not reveal any reduction in survival or appearance of tumors. Mice treated with benzophenone did not show any excess in the number of tumor-bearing animals or in total number of tumors compared to untreated control animals. Although three skin tumors were observed in the benzophenone- treated mice (one case of squamous cell carcinoma and two cases of squamous cell papilloma), there were also three tumors (one carcinoma and toe papillomas) observed in the control animals.

Метаболизм

Benzophenone's main metabolic pathway in the rabbit is by reduction to benzhydrol, which is excreted conjugated with glucuronic acid(Williams, 1959).

Растворимость в органика

Insoluble in water and glycerin, slightly soluble in Propylene glycol, 6% soluble in alcohol, soluble inmost perfume oils.

Перевозки

UN1224 Ketones, liquid, n.o.s., Hazard Class: 3; Labels: 3—Flammable liquid, Technical Name Required. UN3077 Environmentally hazardous substances, solid, n.o.s., Hazard class: 9; Labels: 9—Miscellaneous hazardous material, Technical Name Required.

Методы очистки

Crystallise it from MeOH, EtOH, cyclohexane, *benzene or pet ether, then dry in a current of warm air and store it over BaO or P2O5. It is also purified by zone melting and by sublimation [Itoh J Phys Chem 89 3949 1985, Naguib et al. J Am Chem Soc 108 128 1986, Gorman & Rodgers J Am Chem Soc 108 5074 1986, Ohamoto & Teranishi J Am Chem Soc 108 6378 1986, Naguib et al. J Phys Chem 91 3033 1987]. [Beilstein 7 III 2048, 7 IV 1357.]

Несовместимости

Oxidizing materials, such as dichromates and permanganates.