БЕНЗИЛБРОМИД химические свойства, назначение, производство
Химические свойства
Benzyl bromide is an aromatic compound in which the benzene ring substituted with a bromomethyl group, and is produced by the reaction of toluene with bromine in the presence of an oxidizing agent. It is a combustible, colorless to yellow liquid with a pleasant odor. insoluble in water and easily soluble in most organic solvents. Has a strong tearing effect and unpleasant pungent odor, minimum irritant concentration of 4 mg/m3, intolerable concentration of 50-60 mg/m3.
Использование
Benzyl bromide is widely useful in organic synthesis as a benzyl protecting group for alcohols and carboxylic acids. It is used in the preparation of foaming and frothing agents, quaternary ammonium compounds, peniclins, photographic chemicals, synthetic resins, dyes and plasticizers and esters. It is also involved in the synthesis of (E)-(2-Iodovinyl)benzene by reacting it with diiodomethane.
Определение
ChEBI: Benzyl bromide is a member of the class of benzyl bromides that is toluene substituted on the alpha-carbon with bromine. It has a role as a lachrymator.
Подготовка
Benzyl bromide is synthesized by toluene bromination. Toluene heated to 50°C, add bromine reaction, the reaction temperature of 75-80°C, reaction 6h, fractional distillation at atmospheric pressure to remove the fraction before 140°C, and then distillation under reduced pressure, collect 112-114°C(2.0kPa) fraction, to get benzyl bromide.
Общее описание
Benzyl bromide appears as a colorless liquid with an agreeable odor. Toxic by inhalation and by skin absorption. It is slightly soluble in water and denser than water (density 1.44 g / cm3 (Aldrich)). A lachrymator. Corrosive to metals and tissue.
Реакции воздуха и воды
Sensitive to exposure to light and moisture. Slightly soluble in water.
Профиль реактивности
Benzyl bromide reacts with water, alcohols, common metals (except nickel and lead), bases, amines and oxidizing agents. . Benzyl bromide stored over activated 4A molecular sieve burst a bottle due to condensation-polymerization reaction with generation of HBr gas, [Chem. Eng. News, 1979, 57(12), 74].
Опасность
Highly toxic. Corrosive to skin and tissue. A lachrymator.
Угроза здоровью
Inhalation causes irritation of nose and throat; severe exposure may cause pulmonary edema. Vapors cause severe eye irritation; liquid can burn eyes. Skin contact causes irritation. Ingestion causes irritation of mouth and stomach.
Химическая реактивность
Reactivity with Water Reacts slowly generating hydrogen bromide (hydrobromic acid); Reactivity with Common Materials: Decomposes rapidly in the presence of all common metals except nickel and lead, liberating heat and hydrogen bromide; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Rinse with sodium bicarbonate or lime solution; Polymerization: Polymerizes with evolution of heat and hydrogen bromide when in presence with all common metals except nickel and lead; Inhibitor of Polymerization: None.
Профиль безопасности
Intensely irritating and corrosiveto skin, eyes, and mucous membranes. Large doses causecentral nervous system depression. Mutation datareported. Reaction with molecular sieve produces toxichydrogen bromide gas.
Возможный контакт
It is used as a chemical intermediate;
in organic syntheses; as a foaming and frothing agent.
Перевозки
UN1737 Benzyl Bromide, Hazard class: 6.1;
Labels: 6.1—Poisonous materials, 8—Corrosive material.
Методы очистки
Wash benzyl chloride with conc H2SO4 (CARE), water, 10% Na2CO3 or NaHCO3 solution, and again with water. Dry it with CaCl2, Na2CO3 or MgSO4 and fractionally distil it in the dark, under reduced pressure. It has also been thoroughly degassed at 10-6 mm and redistilled in the dark. This gives material with max (MeCN): 226nm ( 8200) [Mohammed & Kosower J Am Chem Soc 93 2709 1971]. [Beilstein 5 IV 829.] Handle in a fume cupboard, extremely LACHRYMATORY.
Несовместимости
May form explosive mixture with air.
Contact with water forms hydrogen bromide and benzyl
alcohol. Incompatible with strong oxidizers, bases, magnesium.
Attacks metals, except nickel and lead, in the
presence of moisture.
Утилизация отходов
Pour into vermiculite, sodium
bicarbonate, or a sand-soda ash mixture and transfer to
paper boxes, then to an open incinerator. Alternatively, mix
Benzyl Bromide 417
with flammable solvent and spray into incinerator equipped
with after burner and alkali scrubber.
БЕНЗИЛБРОМИД препаратная продукция и сырье
сырьё
препарат