3-Pentanone

Description

Diethyl ketone is a colorless liquid with anacetone-like odor (smells like nail-polish remover). Odorthreshold 2.8 ppm. Molecular weight=86.15; Specificgravity (H2O:1)=0,81 at 25℃; Boiling point=101.6℃;Freezing/Melting point=242℃; Vapor pressure 535 mmHg at 25℃; Flash point=12.8℃ (oc); Autoignitiontemperature=452℃. Explosive limits: LEL=1.6%;UEL=6.4%. Hazard Identification (based on NFPA-704 MRating System): Health 1, Flammability 3, Reactivity 0.Moderately soluble in water.

Chemical Properties

3-Pentanone (also known as diethyl ketone) is a member of the class of compounds known as ketones. It is a colorless liquid ketone with an odor like that of acetone. It is soluble in about 25 parts water, but miscible with organic solvents.3-pentanone is an acetone and ethereal tasting compound and can be found in a number of food items such as strawberry guava, ceylon cinnamon, beech nut, and pak choy, which makes 3-pentanone a potential biomarker for the consumption of these food products.

Uses

Diethyl ketone is used as a solvent, inmedicine, and in organic synthesis.

Uses

3-Pentanone is mainly used as a solvent in paint and a precursor to vitamin E. It is used as a reagent to synthesize ethyl 2-cyano-3,3-diethylacrylate by Knoevenagel condensation. It also shows anticonvulsant effect in several types of mouse seizure models. It serves as an intermediate in the manufacture of pharmaceuticals.

Definition

ChEBI: Pentan-3-one is a pentanone that is pentane carrying an oxo group at position 3. It has been isolated from Triatoma brasiliensis and Triatoma infestans. It has a role as an animal metabolite.

General Description

3-Pentanone is a clear colorless liquid with an acetone-like odor. Flash point 55°F. Less dense than water. Vapors heavier than air.

Air & Water Reactions

Highly flammable. Slightly soluble in water

Reactivity Profile

3-Pentanone is incompatible with the following: Strong oxidizers, alkalis, mineral acids, (hydrogen peroxide + nitric acid) .

Health Hazard

Liquid causes eye burn. Vapor irritates eyes, nose and throat; can cause headache, dizziness, nausea, weakness, and loss of consciousness.

Toxicology

Diethyl ketone is a mild narcotic compoundas well as an irritant. Its acute toxicity is lessthan that of methyl propyl ketone. Exposureto 80,000 ppm for 4 hours was fatal to rats.
LD50 value, oral (rats): 2140 mg/kg.

Fire Hazard

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.

Flammability and Explosibility

Highly flammable

Safety Profile

Moderately toxic by routes. A skin and eye irritant. Mutation data reported. Dangerous fre hazard when exposed to heat or flame; can react vigorously with oxidzing materials. To fight fire, use alcohol foam, foam, CO2, dry chemical. Reacts with hydrogen peroxide + nitric acid to form a shockand heat sensitive explosive peroxide. When heated to decomposition it emits acrid smoke and irritating fumes. See also KETONES.

Synthesis

Ketonic decarboxylation route
3-Pentanone is produced by ketonic decarboxylation of propanoic acid using metal oxide catalysts:
2 CH3CH2CO2H → (CH3CH2)2CO + CO2 + H2O
in the laboratory, the reaction can be conducted in a tube furnace.
Other way to make 3-pentanone: Acetone + very strong base and then + methylating agent -> butanone. Butanone + very strong base, then + methylating agent -> mixture of 3-methylbutanone and 3-pentanone.
Synthesis of 3-pentanone from 1-propanol over CeO2–Fe2O3 catalysts
Vogel's Textbook of Practical Organic Chemistry

Synthesis

3-Pentanone's two synthesis methods : 1) from Propyl alcohol. 2) from Propionic acid.

Potential Exposure

Drug,Mutagen, Primary Irritant. This compound is used as a solvent; in organic synthesis and making medicines.

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.

Shipping

3-Pentanone requires a shipping label of“FLAMMABLE LIQUID.” It falls in Hazard Class 3 andPacking Group II.

Purification Methods

Dry it with anhydrous CaSO4 or CuSO4, and distil from P2O5 under N2 or under reduced pressure. Further purification is by conversion to the semicarbazone (recrystallise to constant m 139o, from EtOH) which, after drying in vacuo over CaCl2 and paraffin wax, is refluxed for 30minutes with excess oxalic acid, then steam distilled and salted out with K2CO3. Dry with Na2SO4 and distil [Cowan et al. J Chem Soc 171 1940]. [Beilstein 1 IV 3279.]

Incompatibilities

Violent reaction with oxidizers, causingfire and explosion hazard. Forms explosive mixture withair. Incompatible with strong acids, aliphatic amines.Attacks many plastics, rubber, and coatings. May accumulate static electrical charges, and may cause ignition of itsvapors.

Waste Disposal

Incineration; molten salt treatment.