Mesityl oxide Chemical Properties

Melting point:

−53 °C(lit.)

Boiling point:

129 °C(lit.)

Density 

0.858 g/mL at 25 °C(lit.)

vapor pressure 

10.5 hPa (20 °C)

refractive index 

n20/D 1.442(lit.)

FEMA 

3368 | 4-METHYL-3-PENTEN-2-ONE

Flash point:

87 °F

storage temp. 

Store below +30°C.

solubility 

30g/l

form 

Liquid, Free Of Suspended Matter

color 

Clear

Specific Gravity

0.86

Odor

Strong; peppermint; honeylike.

explosive limit

1.4-10.1%(V)

Odor Type

vegetable

Water Solubility 

28 G/L (20 ºC)

Merck 

14,5908

JECFA Number

1131

BRN 

1361550

Henry's Law Constant

(x 10^-6 atm?m³/mol): 4.01 at 20 °C (approximate - calculated from water solubility and vapor pressure)

Dielectric constant

15.4（20℃）

Exposure limits

TLV-TWA 60 mg/m³ (15 ppm) (ACGIH), 10-h TWA 40 mg/m³ (10 ppm) (NIOSH); STEL 100 mg/m³ (25 ppm); IDLH 5000 ppm.

Stability:

Light Sensitive

LogP

1.37 at 20℃

CAS DataBase Reference

141-79-7(CAS DataBase Reference)

NIST Chemistry Reference

3-Penten-2-one, 4-methyl-(141-79-7)

EPA Substance Registry System

Mesityl oxide (141-79-7)

Safety Information

Hazard Codes 

Xn

Risk Statements 

10-20/21/22-36/37/38

Safety Statements 

25

OEB

A

OEL

TWA: 10 ppm (40 mg/m3)

RIDADR 

UN 1229 3/PG 3

WGK Germany 

1

RTECS 

SB4200000

Autoignition Temperature

344 °C

TSCA 

Yes

HS Code 

2914 19 90

HazardClass 

3

PackingGroup 

III

Hazardous Substances Data

141-79-7(Hazardous Substances Data)

Toxicity

LD50 in mice (mg/kg): 710 ±85 intragastric; LC50 in mice (2 hr), rats (4 hr) (mg/m3): 10000 ±270, 9000 ±600 (Ismerov)

IDLA

1,400 ppm [10% LEL]

MSDS

• Language:English Provider:SigmaAldrich
• Language:English Provider:ACROS
• Language:English Provider:ALFA

Mesityl oxide Usage And Synthesis

Description

Mesity oxide(141-79-7) is a tri-functional intermediate of considerable utility in the synthesis of a number of different types of organic compounds, such as mesityl oxide can be hydrogenated to methyl isobutyl ketone and other flavor ingredients in foods, such as 4- methyl-pentanone. Mesityl oxide can be used as a solvent for resins, gums, nitrocellulose, oils, lacquers, and inks. It is also used as an insect repellant and used in ore flotation.

References

[1] Pradyot Patnaik, A Comprehensive Guide to the Hazardous Properties of Chemical Substances, 3rd Edition, 2007
[2] Klaus Weissermel, and Hans-Jürgen Arpe, Industrial Organic Chemistry, 3rd Edition, 1997
[3] George A. Burdock, Fenaroli’s Handbook of Flavor Ingredients, 4th Edition, 2001

Description

The commercial grade of 4-methyl-3-penten-2-one exhibits an unpleasant grassy-green or pungent, acrylic odor. The pure material has a pleasant, honey-like odor. This substance may be prepared by reacting acetone or diacetone alcohol with iodine or other dehydrating agent; by condensation of acetone over sulfonated polystyrene-divinylbenzene resin used as an ion exchange catalyst.

Chemical Properties

Mesityl oxide is a clear, pale yellow, or colorless liquid with a strong peppermint odor. The odor threshold is 0.05 ppm.

Physical properties

Clear, pale yellow liquid with a strong, peppermint, or honey-like odor. Experimentally determined detection and recognition odor threshold concentrations were 70 μg/m³ (17 ppb_v) and 200 μg/m³ (50 ppb_v), respectively (Hellman and Small, 1974).

Occurrence

Reported found in orange juice, baked potato, bell pepper, sauerkraut, tomato, crisp bread, parmesan cheese, milk, chicken fat, hop oil, rum, coffee, tea, peanut, passion fruit, mushroom, tamarind, prickly pear, buckwheat, basil, elder flower, rosemary, shrimp, nectarine, clam and maté

Uses

4-Methyl-4-penten-2-one is used to a small extent as an intermediate in synthesis. Most of it is converted to 4-methyl-2-pentanone by selective hydrogenation. Although 4-methyl-2- pentanone has excellent solvent properties for nitrocellulose, cellulose esters and ethers, copolymers of vinyl chloride – vinyl acetate and other synthetic resins, as well as natural and synthetic rubber, its use as a solvent is limited as a result of its toxicity and chemical instability. The fraction of 4-methyl-4-penten-2-one permitted in solvent systems has been set at 5 vol% (Rule 66 of the Los Angeles, California, Air Pollution Control District). Some of the numerous possible reactions that mesityl oxide may undergo have been used for the synthesis of products such as Budralazine, an antihypertensive agent.

Uses

Solvent for nitrocellulose, many gums and resins, particularly vinyl resins. In lacquers, varnishes and enamels. In making methyl isobutyl ketone.

Definition

ChEBI: 4-Methyl-3-penten-2-one, 9CI is an olefinic compound. It is functionally related to an acrylic acid.

Preparation

4-Methyl-4-penten-2-one is the precursor of methyl isobutyl ketone (see Section 2.2) and can be produced from acetone in a single- or a two-step process . Pure mesityl oxide is obtained by azeotropic distillation of the crude watercontaining product. Subsequent purification by removal of the accompanying impurities, such as mesitylene and phorone [504-20-1], is effected by distillation.

Synthesis Reference(s)

Tetrahedron Letters, 27, p. 3733, 1986 DOI: 10.1016/S0040-4039(00)83866-6

General Description

Mesityl oxide appears as a colorless, oily liquid with a pungent honey-like odor. Flash point 87 °F. Less dense than water and slightly soluble in water. Vapors heavier than air. Used in paint removers, as a solvent for plastics, and as an insect repellent.

Air & Water Reactions

Highly flammable. Slightly soluble in water

Reactivity Profile

Mixing MESITYL OXIDE in equal molar proportions with any of the following substances in a closed container caused the temperature and pressure to increase: 2-aminoethanol, chlorosulfonic acid, ethylene diamine, nitric acid, oleum, or sulfuric acid [NFPA 1991].

Hazard

Flammable, moderate fire risk. Toxic by ingestion, inhalation, and skin absorption. Eye and upper respiratory tract irritant, central nervous system impairment.

Health Hazard

Inhalation causes irritation of nose and throat, headache, dizziness, difficult breathing. Contact with liquid or concentrated vapor causes severe eye irritation. Liquid irritates skin. Ingestion causes irritation of mouth and stomach.

Health Hazard

Mesityl oxide is a moderately toxic substance, more toxic than the saturated ketones.Inhalation of its vapors can cause irritationto the eyes, skin, and mucous membranes. Inhumans, the irritation effect on the eyes andnose are reported to be 25 and 50 ppm. Athigh concentrations narcosis can result. Otherthan narcosis, prolonged exposure to highconcentrations can injure the lungs, liver, and kidney. A concentration of 2500 ppm waslethal to rats.
LD50 value, oral (rats): 1120 mg/kg.

Fire Hazard

Behavior in Fire: Vapor is heavier than air and may travel a considerable distance to a source of ignition and flash back.

Safety Profile

Poison by intraperitoneal route. Moderately toxic by ingestion. Mildly toxic by inhalation and skin contact. Human systemic effects by inhalation: conjunctiva irritation. This compound is highly irritating to all tissues on contact; its vapors also are irritating. High concentrations are narcotic. It is readdy absorbed through intact skin. Single exposures tend to indicate that ths ketone has greater acute and narcotic action than isophorone. It can have harmful effects upon the hdneys and liver, and may damage the eyes and lungs to a serious degree. Prolonged exposure can injure liver, kidneys, and lungs. It can cause opaque cornea, keratoconus, and extensive necrosis of cornea. Dangerous fire hazard when exposed to heat, sparks, or flame; can react with oxidzing materials. Reacts violently with 2-amino ethanol, chlorosulfonic acid, ethylene diamine, HNO3, oleum, H2SO4. An insect repellent. To fight fire, use alcohol foam, CO2, dry chemical. When heated to decomposition it emits acrid smoke and irritating fumes. See also KETONES.

Potential Exposure

Mesityl oxide is used as a solvent for cellulose esters and ethers and other resins in lacquers and inks. It is used in paint and varnish removers and as an insect repellent

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. Seekmedical attention immediately. If this chemical contactsthe skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove fromexposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. Give large quantities of water and induce vomiting. Do not make an unconscious person vomit.

storage

Color Code—Red: Flammability Hazard: Store in a flammable liquid storage area or approved cabinet away from ignition sources and corrosive and reactive materials. Mesityl oxide 1715 Prior to working with this chemical you should be trained on its proper handling and storage. Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in tightly closed containers in a cool, well-ventilated area away from oxidizers, strong acids. See incompatibilities above. Where possible, automatically pump liquid from drums or other storage containers to process containers.

Shipping

UN1229 Mesitly oxide, Hazard Class: 3; Labels: 3-Flammable liquid.

Purification Methods

Purify it by distillation, preferably in a vacuum or via the semicarbazone (m 165o) which is decomposed to pure ketone. The 2,4-dinitrophenylhydrazone (m 205-206o) crystallises from EtOH. [Johnson J Am Chem Soc 73 5888 1951, Johnson J Am Chem Soc 75 2720 1953, Erskine & Waight J Chem Soc 3425 1960, Beilstein 1 H 736, 1 I 382, 1 II 793, 1 III 2995, 1 IV 3471.]

Incompatibilities

May form explosive mixture with air. May be able to form explosive peroxides. May react violently with nitric acid; aliphatic amines; alkanolamines, 2- aminoethanol, ethylene diamine; chlorosulfonic acid; oleum (fuming sulfuric acid). Not compatible with oxidizers, strong acids; strong bases; reducing agents; halogens. Dissolves some forms of plastics, resins and rubber. Attacks copper.

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.

Mesityl oxide(141-79-7)Related Product Information

• Isovanillin
• Isoniazid
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• 3,5-Dimethyl-2-cyclohexen-1-one
• 2,6-DIMETHYLBENZOQUINONE
• (-)-VERBENONE
• 3-Methyl-2-cyclohexen-1-one
• 3-methylcyclopent-2-en-1-one
• Isophorone
• 2,5-DIPHENYL-P-BENZOQUINONE
• DUROQUINONE
• 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone
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• 2,3-Dimethoxy-5-methyl-p-benzoquinone
• THYMOQUINONE
• 4-Methyl-3-penten-2-one (phthalazin-1-yl)hydrazone
• TRIMESITYLPHOSPHINE