2-Pentanone

Description

MPK is a colorless to water-white liquid witha strong odor resembling acetone and ether. The odorthreshold is 7.7 ppm. Molecular weight = 86.15; Specificgravity (H2O:1) 5 0.81; Boiling point = 102℃; Freezing/Melting point 5 2 78℃; Vapor pressure 5 27 mmHg at20℃; Flash point = 7℃ (cc); Autoignition temperature 5452℃. Explosive limits: LEL 5 1.5%; UEL 5 8.2%.Hazard Identification (based on NFPA-704 M RatingSystem): Health 2, Flammability 3, Reactivity 0. Slightlysoluble in water; solubility 5 6%

Chemical properties

MPK is a colorless to water-white liquid with a strong odor resembling acetone and ether.

Chemical properties

2-Pentanone has an ethereal, fruity odor.

Physical properties

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.

Occurrence

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.

The Uses of 2-Pentanone

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.

Definition

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.

Preparation

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.

Production Methods

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.

What are the applications of Application

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.

Aroma threshold values

Detection: 70 ppb

Taste threshold values

Taste characteristics at 25 ppm: sweet, fruity and banana-like with a fermented nuance.

General Description

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.

Air & Water Reactions

Highly flammable. Soluble in water.

Reactivity Profile

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

Hazard

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

Health Hazard

Exposure can cause irritation of eyes, nose and throat.

Health Hazard

Inhalation of MPK vapors can cause narcosisand irritation of the eyes and respiratorytract. Chronic poisoning from this compoundis not known. Exposure to 1500 ppm wasseverely irritating to humans and 2000 ppmfor 4 hours was fatal to rats. In guinea pigs5000 ppm produced coma.

Fire Hazard

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).

Biochem/physiol Actions

Taste at 20 ppm

Safety Profile

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

Potential Exposure

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.

First aid

If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit.

Environmental Fate

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.

storage

Color Code—Red: Flammability Hazard: Store ina flammable liquid storage area or approved cabinet awayfrom ignition sources and corrosive and reactive materials.Prior to working with this chemical you should be trainedon its proper handling and storage. Before entering confinedspace where this chemical may be present, check to makesure that an explosive concentration does not exist. Methylpropyl ketone must be stored to avoid contact with oxidizers since violent reactions occur. Store in tightly closedcontainers in a cool, well-ventilated area away from heat,sparks, or flame. Sources of ignition, such as smoking andopen flames, are prohibited where methyl propyl ketone ishandled, used, or stored. Metal containers used in the transfer of 5 gallons or more of methyl propyl ketone should begrounded and bonded. Drums must be equipped with selfclosing valves, pressure vacuum bungs, and flame arresters.Use only nonsparking tools and equipment, especially whenopening and closing containers of methyl propyl ketone.Wherever methyl propyl ketone is used, handled, manufactured, or stored, use explosion-proof electrical equipmentand fittings.

Shipping

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

Purification Methods

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.]

Incompatibilities

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

Waste Disposal

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.