Acetal

Product Name:

Acetal

Synonyms:

1,1-DIETHOXYETHANE;1,1-DIETHOXYACETAL;ACETAL;ACETALDEHYDE DIETHYL ACETAL;DIETHYL ACETAL;FEMA 2002;ETHYLIDENE DIETHYL ETHER;Acetal~1,1-Diethoxyethane

CAS:

105-57-7

MF:

C6H14O2

MW:

118.17

EINECS:

203-310-6

Product Categories:

Pharmaceutical Intermediates

Mol File:

105-57-7.mol

Melting point 

-100 °C

Boiling point 

103 °C

density 

0.831 g/mL at 25 °C(lit.)

vapor density 

4.1 (vs air)

vapor pressure 

20 mm Hg ( 20 °C)

FEMA 

2002 | ACETAL

refractive index 

n20/D 1.379-1.383(lit.)

Fp 

-6 °F

storage temp. 

Refrigerator (+4°C) + Flammables area

solubility 

46g/l

form 

Liquid

color 

Clear colorless

explosive limit

1.6-10.4%(V)

Water Solubility 

46 g/L (25 ºC)

JECFA Number

941

Merck 

14,38

BRN 

1098310

Stability:

Stable. Highly flammable. May form peroxides in storage. Test for peroxides before use. Vapors may form an explosive mixture with air, and may travel to source of ignition and flash back. Vapors may spread along ground and collect in low or confined areas (sewers, basements, tanks).

InChIKey

DHKHKXVYLBGOIT-UHFFFAOYSA-N

CAS DataBase Reference

105-57-7(CAS DataBase Reference)

NIST Chemistry Reference

Ethane, 1,1-diethoxy-(105-57-7)

EPA Substance Registry System

Diethyl acetal (105-57-7)

Hazard Codes 

F,Xi

Risk Statements 

11-36/38

Safety Statements 

9-16-33

RIDADR 

UN 1088 3/PG 2

WGK Germany 

2

RTECS 

AB2800000

Autoignition Temperature

446 °F &_& 446 °F

TSCA 

Yes

HazardClass 

3

PackingGroup 

II

HS Code 

29110000

Hazardous Substances Data

105-57-7(Hazardous Substances Data)

Toxicity

LD50 orally in rats: 4.57 g/kg (Smyth)

Description

Acetal (full name: Acetaldehyde diethyl acetal/1,1-Diethoxyethane) is a major flavoring component of distilled beverages, especially malt whisky and sherry.
Acetaldehyde diethyl acetal is used as a flavoring agent to provide fruit, nut, rum, and whiskey flavors. It can react with diketene to form ethyl 5-ethoxy-3-oxohexanoate in the presence of titanium chloride. It can also be used to synthesize mixed acetal glycosides via transacetalation.

Synthesis

Acetaldehyde diethyl acetal can be obtained by the reaction between ethyl alcohol and acetaldehyde in the presence of anhydrous calcium chloride.

Description

Acetal is a clear, colourless, and extremely flammable liquid with an agreeable odour. The vapour is susceptible to cause flash fire. Acetal is sensitive to light and, on storage, may form peroxides. In fact, it has been reported to be susceptible to autoxidation and should, therefore, be classified as peroxidisable. Acetal is incompatible with strong oxidising agents and acids.

Chemical Properties

clear, colorless liquid

Chemical Properties

Acetal is a clear, colorless, and extremely fl ammable liquid with an agreeable odor. The vapor may cause fl ash fi re. Acetal is sensitive to light and on storage may form peroxides. In fact, it has been reported to be susceptible to autoxidation and should, therefore, be classifi ed as peroxidizable. Acetal is incompatible with strong oxidizing agents and acids.

Chemical Properties

Acetal, an aldehyde, is a clear, volatile liquid with an agreeable odor

Chemical Properties

Acetal.has.a.refreshing,.pleasant,.fruity-green.odor

Uses

Solvent; in synthetic perfumes such as jasmine; in organic syntheses.

Definition

A type of organic compound formed by addition of an alcohol to an aldehyde. Addition of one alcohol molecule gives a hemiacetal. Further addition yields the full acetal. Similar reactions occur with ketones to produce hemiketals and ketals.

Preparation

From.ethyl.alcohol.and.acetaldehyde.in.the.presence.of.anhydrous.calcium.chloride.or.small.amounts.of.mineral. acids.(HCl).

Aroma threshold values

Detection:.4.to.42.ppb

General Description

A clear colorless liquid with a pleasant odor. Boiling point 103-104°C. Flash point -5°F. Density 0.831 g / cm3. Slightly soluble in water. Vapors heavier than air. Moderately toxic and narcotc in high concentrations.

Air & Water Reactions

Highly flammable. Forms heat-sensitive explosive peroxides on contact with air. Slightly soluble in water.

Reactivity Profile

Acetal can react vigorously with oxidizing agents. Stable in base but readily decomposed by dilute acids. Forms heat-sensitive explosive peroxides on contact with air. Old samples have been known to explode when heated due to peroxide formation [Sax, 9th ed., 1996, p. 5].

Health Hazard

May irritate the upper respiratory tract. High concentrations act as a central nervous system depressant. Symptoms of exposure include headache, dizziness, drowsiness, abdominal pain, and nausea.

Health Hazard

Mild irritant to skin and eyes; acute toxicityof low order; narcotic at high concentrations;4-hour exposure to 4000 ppm lethal to mice;the oral LD50 value for mice is 3500 mg/kg.

Health Hazard

Exposures to acetal cause irritation to the eyes, skin, gastrointestinal tract, nausea, vomit- ing, and diarrhea. In high concentrations, acetal produces narcotic effects in workers.

Fire Hazard

Highly flammable; flash point (closed cup) -21°C (-6°F); vapor density 4.1 (air = 1), vapor heavier than air and can travel some distance to a source of ignition and flash back; autoignition temperature 230°C (446°F); vapor forms explosive mixtures with air, LEL and UEL values are 1.6% and 10.4% by volume in air, respectively (DOT Label: Flammable Liquid, UN 1088). .

Safety Profile

Moderately toxic by ingestion, inhalation, and intraperitoneal routes.A skin and eye irritant. A narcotic. Dangerous fire hazard when exposed to heat or flame; can react vigorously with oxidizing materials. Forms heat-sensitive explosive peroxides on contact with air. when heated to decomposition it emits acrid smoke and fumes. See also ETHERS and ALDEHYDES.

Potential Exposure

Used as a solvent; in synthetic perfumes, such as jasmine, cosmetics, flavors; in organic synthesis.

Shipping

UN1088 Acetal, Hazard Class: 3; Labels: 3-Flammable liquid. UN1988 Aldehydes, flammable, toxic, n.o.s., Hazard Class: 3; Labels: 3-Flammable liquid, 6.1-Poisonous materials, Technical Name Required

Purification Methods

Dry acetal over Na to remove alcohols and H2O, and to polymerise aldehydes, then fractionally distil. Or, treat it with alkaline H2O2 at 40-45o to remove aldehydes, then saturate with NaCl, separate, dry with K2CO3 and distil it from Na [Vogel J Chem Soc 616 1948]. [Beilstein 1 IV 3103.]

Incompatibilities

Aldehydes are frequently involved in self-condensation or polymerization reactions. These reactions are exothermic; they are often catalyzed by acid. Aldehydes are readily oxidized to give carboxylic acids. Flammable and/or toxic gases are generated by the combination of aldehydes with azo, diazo compounds, dithiocarbamates, nitrides, and strong reducing agents. Aldehydes can react with air to give first peroxo acids, and ultimately carboxylic acids. These autoxidation reactions are activated by light, catalyzed by salts of transition metals, and are autocatalytic (catalyzed by the products of the reaction). The addition of stabilizers (antioxidants) to shipments of aldehydes retards autoxidation. Presumed to form explosive peroxides on contact with air and light. May accumulate static electrical charges, and may cause ignition of its vapors.

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.

Preparation Products

(1R-cis)-3-(2,2-dibromoethenyl)-2,2-dimethylcyclopropane carboxylic acid-->n-Butyl vinyl ether-->2,2-Dibromo-2-cyanoacetamide-->Misoprostol-->WL 108477-->1R-trans-methyl caronaldehydate-->Chloroacetaldehyde diethyl acetal-->4-Fluoro-3-phenoxybenzaldehyde-->Mecillinam-->Dirithromycin-->Phenylpropyl aldehyde-->3-Chloropropionaldehyde diethylacetal-->CIS-4-HEPTENAL-->TRANS-2-HEXENAL-->FEMA 3378

Raw materials

Potassium carbonate-->Calcium chloride-->Acetaldehyde