2-пентанона

Химические свойства

2-Pentanone has an ethereal, fruity odor.

Физические свойства

Clear, colorless, very flammable liquid with a characteristic, pungent odor. An odor threshold concentration of 20 ppb_v was determined by a triangular odor bag method (Nagata and Takeuchi, 1990). Cometto-Mu?iz et al. (2000) reported nasal pungency threshold concentration ranging from approximately 500 to 3,200 ppm.

Вхождение

Reported found in wood spirit; also present in Ananas sativus; a few banana species, grapevines and some citrus fruits. Also reported found in over 120 foods and beverages including fresh apple, papaya, fresh blackberry, vinegar, wheaten bread, other types of bread, Swiss cheese, Camembert cheese, cheddar cheese, other cheeses, white wine, unprocessed rice, water yam, apricot, orange juice, guava, grapes, pear, pineapple, strawberry, asparagus, carrot, celery, peas, tomato, butter, yogurt, cream, milk powder, buttermilk, boiled egg, caviar, raw fish, cooked chicken and beef, pork fat, pork liver, hop oil, beer, cognac, rum, bourbon whiskey, white wine, cocoa, coffee, roasted filberts and peanuts, peanut oil, potato chips, oat flakes, honey, soybean, passion fruit, plum, beans, mushroom, starfruit, trassi, mango, globe artichoke, rice, soursop, malt, loquat, endive, shrimp, crab, lamb’s lettuce and cape gooseberry.

Использование

2-Pentanone is used as a solvent for lacquers and surface coatings. It acts as a flavoring agent. It is also used as a solvent for cleaning and degreasing purpose. Further, it serves as an intermediate, paint additive and coating additive.

Определение

ChEBI: 2-Pentanone is a pentanone carrying an oxo substituent at position 2. It has a role as a plant metabolite. It is a methyl ketone and a pentanone.

Подготовка

2-Pentanone was Prepared by dry distillation of a mixture consisting of calcium acetate and calcium butyrate; also by oxidation of sodium or ammonium n-caproate with H2O2.

прикладной

2-Pentanone is a flavoring agent that is a clear liquid, colorless, with flowery odor. it is miscible in alcohol and ether and soluble in water. it is obtained by chemical synthesis. it is also termed methyl propyl ketone. Methyl propyl ketone (MPK) is used as a solvent, substitute for diethyl ketone, in organic synthesis.

Методы производства

MPK can be manufactured by oxidation of 2-pentanol, from ethylene and methyl acetoacetate, or by distillation of a mixture of calcium acetate and calcium butyrate. Commercial purity can be 90% MPK; however, some commercial materials are a mixture of MPK and diethylketone with small amounts of sec-amyl acetate.

Общее описание

A clear colorless liquid with the odor of fingernail polish. Flash point 45°F. Less dense than water and soluble in water. Hence floats on water. Density 0.809 g / cm3. Vapors heavier than air.

Реакции воздуха и воды

Highly flammable. Soluble in water.

Профиль реактивности

2-Pentanone is incompatible with oxidizing agents, strong bases and reducing agents. Reacts violently with bromine trifluoride .

Опасность

Flammable, dangerous fire risk, explosivelimits in air 1.6–8.2%. Eye irritant and affects pul-monary function.

Угроза здоровью

Exposure can cause irritation of eyes, nose and throat.

Пожароопасность

Flammable liquid; flash point (closed cup) 7°C (45°F); vapor density 3 (air = 1); vapor pressure 27 torr at 20°C (68°F); the vapor can travel a considerable distance to an ignition source and flash back; autoignition temperature 452°C (846°F); fire- extinguishing agent: “alcohol” foam; a water spray may be used to absorb the heat and flush the spill away from exposures. MPK forms an explosive mixture with air in the range 1.5–8.2% by volume of air. Heating with oxidizers can cause an explosion (U.S. EPA 1988).

Профиль безопасности

Moderately toxic by ingestion and intraperitoneal routes. Mildly toxic by skin contact and inhalation. Human systemic effects by inhalation: headache, nausea, irritation of the respiratory passages, eyes, and skin. A skin irritant. Mutation data reported. A hghly flammable liquid. A very dangerous fire hazard when exposed to heat or flame; can react vigorously with oxidzing materials. An explosion hazard in the form of vapor when exposed to heat or flame. To fight fue, use alcohol foam. Mxtures with bromine trifluoride may explode during evaporation. When heated to decomposition it emits acrid smoke and irritating fumes. See also KETONES

Возможный контакт

MPK is used as a solvent; as a synthetic food flavoring agent; and in organic synthesis; as a solvent replacement for diethyl ketone and acetone.

Экологическая судьба

Chemical/Physical. Atkinson et al. (2000) studied the gas-phase reaction of 2-pentanone with OH radicals in purified air at 25 °C and 740 mmHg. A relative rate constant of 4.56 x 10^-12 cm³/molecule·sec was calculated for this reaction. Reaction products identified by GC, FTIR, and atmospheric pressure ionization tandem mass spectroscopy were (with respective molar yields) were: formaldehyde, 1.03; acetaldehyde, 0.51; propanal, 0.19; 2,4-pentanedione, 0.12; and molecular weight 147 organic nitrates.
At an influent concentration of 1.0 g/L, treatment with GAC resulted in an effluent concentration of 305 mg/L. The adsorbability of the GAC was 139 mg/g carbon (Guisti et al., 1974).
Will not hydrolyze in water because 3-pentanone does not contain a hydrolyzable group.

Перевозки

UN1249 Methyl propyl ketone, Hazard Class: 3; Labels: 3-Flammable liquid.

Методы очистки

Purify the ketone by refluxing it with a little KMnO4, dry it with CaSO4 and distil it. It can be converted to its bisulfite addition compound by shaking with excess saturated aqueous NaHSO3 at room temperature, cooling to 0o, filtering, washing with diethyl ether and drying. Steam distillation of the adduct gives a distillate from which the ketone is recovered, washed with aqueous NaHCO3 and distilled water, dried (K2CO3) and fractionally distilled. [Waring & Garik J Am Chem Soc 78 5198 1956, Beilstein 1 IV 3271.]

Несовместимости

Ketones are incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides, nitrated amines, azo, diazo, azido compounds, carbamates, organic cyanates. Attacks some plastics

Утилизация отходов

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.