Dimethoxymethane

Last updated
Dimethoxymethane
Dimethoxymethane-2D-skeletal.png
Dimethoxymethane-gauche-gauche-conformer-3D-balls.png
Names
Preferred IUPAC name
Dimethoxymethane
Other names
Formal

Formaldehyde dimethyl ether
Methylal
Dimethylformal (DMFL)
Formaldehyde dimethylacetal
Methoxymethyl methyl ether

Methylene dimethyl ether

Contents

Identifiers
3D model (JSmol)
1697025
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.003.378 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 203-714-2
100776
MeSH Dimethoxymethane
PubChem CID
RTECS number
  • PA8750000
UNII
UN number 1234
  • InChI=1S/C3H8O2/c1-4-3-5-2/h3H2,1-2H3 Yes check.svgY
    Key: NKDDWNXOKDWJAK-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C3H8O2/c1-4-3-5-2/h3H2,1-2H3
    Key: NKDDWNXOKDWJAK-UHFFFAOYAE
  • COCOC
Properties
C3H8O2
Molar mass 76.095 g·mol−1
AppearanceColorless liquid [1]
Odor Chloroform-like [1]
Density 0.8593 g cm−3 (at 20 °C) [1]
Melting point −105 °C (−157 °F; 168 K) [1] [2]
Boiling point 42 °C (108 °F; 315 K) [1] [2]
33% (20 °C) [3] [ clarification needed ]
Vapor pressure 330 mmHg (20 °C) [3]
−47.3·10−6 cm3/mol
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-exclam.svg
Danger
H225, H315, H319, H335
P210, P233, P240, P241, P242, P243, P261, P264, P271, P280, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P370+P378, P403+P233, P403+P235, P405, P501
Flash point −18 °C (0 °F; 255 K)
Explosive limits 2.2–13.8% [3]
Lethal dose or concentration (LD, LC):
5708 mg/kg (rabbit, oral) [4]
18000 ppm (mouse, 7 hr)
15000 ppm (rat)
18354 ppm (mouse, 7 hr) [4]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 1000 ppm (3100 mg/m3) [3]
REL (Recommended)
TWA 1000 ppm (3100 mg/m3) [3]
IDLH (Immediate danger)
2200 ppm [3]
Related compounds
Related Ethers
Dimethoxyethane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Dimethoxymethane, also called methylal, is a colorless flammable liquid with a low boiling point, low viscosity and excellent dissolving power. It has a chloroform-like odor and a pungent taste. It is the dimethyl acetal of formaldehyde. Dimethoxymethane is soluble in three parts water[ clarification needed ] and miscible with most common organic solvents.

Synthesis and structure

It can be manufactured by oxidation of methanol or by the reaction of formaldehyde with methanol. In aqueous acid, it is hydrolyzed back to formaldehyde and methanol.

Due to the anomeric effect, dimethoxymethane has a preference toward the gauche conformation with respect to each of the C–O bonds, instead of the anti conformation. Since there are two C–O bonds, the most stable conformation is gauche-gauche, which is around 7 kcal/mol more stable than the anti-anti conformation, while the gauche-anti and anti-gauche are intermediate in energy. [5] Since it is one of the smallest molecules exhibiting this effect, which has great interest in carbohydrate chemistry, dimethoxymethane is often used for theoretical studies of the anomeric effect.

Applications

Industrially, it is primarily used as a solvent and in the manufacture of perfumes, resins, adhesives, paint strippers and protective coatings. Another application is as a gasoline-additive for increasing octane number. Dimethoxymethane can also be used for blending with diesel. [6]

Reagent in organic synthesis

Another useful application of dimethoxymethane is to protect alcohols with a methoxymethyl (MOM) ether in organic synthesis. Dimethoxymethane can be activated with phosphorus pentoxide in dichloromethane or chloroform. [7] This method is preferred to the use of chloromethyl methyl ether (MOMCl). Phenols can also be MOM-protected using dimethoxymethane, p-toluenesulfonic acid. [8] Alternatively, MOMCl can be generated as a solution by treating dimethoxymethane with an acyl chloride in the presence of a Lewis acid catalyst like zinc bromide:

MeOCH2OMe + RC(=O)Cl → MeOCH2Cl + RC(=O)(OMe)).

Unlike the classical procedure, which uses formaldehyde and hydrogen chloride as starting materials, the highly carcinogenic side product bis(chloromethyl) ether is not generated. [9]

Related Research Articles

<span class="mw-page-title-main">Tetrahydrofuran</span> Cyclic chemical compound, (CH₂)₄O

Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water-miscible organic liquid with low viscosity. It is mainly used as a precursor to polymers. Being polar and having a wide liquid range, THF is a versatile solvent.

<span class="mw-page-title-main">Dichloromethane</span> Chemical compound

Dichloromethane is an organochlorine compound with the formula CH2Cl2. This colorless, volatile liquid with a chloroform-like, sweet odor is widely used as a solvent. Although it is not miscible with water, it is slightly polar, and miscible with many organic solvents.

<span class="mw-page-title-main">Methylamine</span> Organic chemical compound

Methylamine is an organic compound with a formula of CH3NH2. This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine.

Morpholine is an organic chemical compound having the chemical formula O(CH2CH2)2NH. This heterocycle features both amine and ether functional groups. Because of the amine, morpholine is a base; its conjugate acid is called morpholinium. For example, treating morpholine with hydrochloric acid makes the salt morpholinium chloride. It is a colorless liquid with a weak, ammonia- or fish-like odor. The naming of morpholine is attributed to Ludwig Knorr, who incorrectly believed it to be part of the structure of morphine.

<i>tert</i>-Butyl alcohol Chemical compound

tert-Butyl alcohol is the simplest tertiary alcohol, with a formula of (CH3)3COH (sometimes represented as t-BuOH). Its isomers are 1-butanol, isobutanol, and butan-2-ol. tert-Butyl alcohol is a colorless solid, which melts near room temperature and has a camphor-like odor. It is miscible with water, ethanol and diethyl ether.

<span class="mw-page-title-main">Dimethyl sulfate</span> Chemical compound

Dimethyl sulfate (DMS) is a chemical compound with formula (CH3O)2SO2. As the diester of methanol and sulfuric acid, its formula is often written as (CH3)2SO4 or Me2SO4, where CH3 or Me is methyl. Me2SO4 is mainly used as a methylating agent in organic synthesis.

<span class="mw-page-title-main">1-Propanol</span> Primary alcohol compound

1-Propanol is a primary alcohol with the formula CH3CH2CH2OH and sometimes represented as PrOH or n-PrOH. It is a colourless liquid and an isomer of 2-propanol. It is formed naturally in small amounts during many fermentation processes and used as a solvent in the pharmaceutical industry, mainly for resins and cellulose esters, and, sometimes, as a disinfecting agent.

Benzyl chloride, or α-chlorotoluene, is an organic compound with the formula C6H5CH2Cl. This colorless liquid is a reactive organochlorine compound that is a widely used chemical building block.

<span class="mw-page-title-main">Isoamyl alcohol</span> Chemical compound

Isoamyl alcohol is a colorless liquid with the formula C
5
H
12
O
, specifically (H3C–)2CH–CH2–CH2–OH. It is one of several isomers of amyl alcohol (pentanol). It is also known as isopentyl alcohol, isopentanol, or (in the IUPAC recommended nomenclature) 3-methyl-butan-1-ol. An obsolete name for it was isobutyl carbinol.

<span class="mw-page-title-main">2-Methoxyethanol</span> Chemical compound

2-Methoxyethanol, or methyl cellosolve, is an organic compound with formula C
3
H
8
O
2
that is used mainly as a solvent. It is a clear, colorless liquid with an ether-like odor. It is in a class of solvents known as glycol ethers which are notable for their ability to dissolve a variety of different types of chemical compounds and for their miscibility with water and other solvents. It can be formed by the nucleophilic attack of methanol on protonated ethylene oxide followed by proton transfer:

Chloroalkyl ethers are a class of organic compounds with the general structure R-O-(CH2)n-Cl, characterized as an ether connected to a chloromethyl group via an alkane chain.

The Blanc chloromethylation is the chemical reaction of aromatic rings with formaldehyde and hydrogen chloride to form chloromethyl arenes. The reaction is catalyzed by Lewis acids such as zinc chloride. The reaction was discovered by Gustave Louis Blanc (1872-1927) in 1923

<span class="mw-page-title-main">Propargyl alcohol</span> Chemical compound

Propargyl alcohol, or 2-propyn-1-ol, is an organic compound with the formula C3H4O. It is the simplest stable alcohol containing an alkyne functional group. Propargyl alcohol is a colorless viscous liquid that is miscible with water and most polar organic solvents.

<span class="mw-page-title-main">Nitroethane</span> Chemical compound

Nitroethane is an organic compound having the chemical formula C2H5NO2. Similar in many regards to nitromethane, nitroethane is an oily liquid at standard temperature and pressure. Pure nitroethane is colorless and has a fruity odor.

Tetramethyl orthosilicate (TMOS) is the chemical compound with the formula Si(OCH3)4. This molecule consists of four methoxy groups bonded to a silicon atom. The basic properties are similar to the more popular tetraethyl orthosilicate, which is usually preferred because the product of hydrolysis, ethanol, is less toxic than methanol.

<span class="mw-page-title-main">Chloromethyl methyl ether</span> Chemical compound

Chloromethyl methyl ether (CMME) is a compound with formula CH3OCH2Cl. A colorless liquid, it is a chloroalkyl ether. It is used as an alkylating agent. In organic synthesis, it is used for introducing the methoxymethyl ether (MOM) protecting group, and is thus often called MOM-Cl or MOM chloride. It also finds application as a chloromethylating agent in some variants of the Blanc chloromethylation.

<span class="mw-page-title-main">Bis(chloromethyl) ether</span> Chemical compound

Bis(chloromethyl) ether is an organic compound with the chemical formula (ClCH2)2O. It is a colourless liquid with an unpleasant suffocating odour and it is one of the chloroalkyl ethers. Bis(chloromethyl) ether was once produced on a large scale, but was found to be highly carcinogenic and thus such production has ceased.

<span class="mw-page-title-main">Chloroacetaldehyde</span> Chemical compound

Chloroacetaldehyde is an organic compound with the formula ClCH2CHO. Like some related compounds, it is highly electrophilic reagent and a potentially dangerous alkylating agent. The compound is not normally encountered in the anhydrous form, but rather as the hemiacetal (ClCH2CH(OH))2O.

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<span class="mw-page-title-main">Polyoxymethylene dimethyl ethers</span> Chemical compound

Polyoxymethylene dimethyl ethers (PODE or DMMn) are a class of chemical compounds with the molecular formula H3CO(CH2O)nCH3 where n is typically about 3 to 8.

References

  1. 1 2 3 4 5 Merck Index, 11th Edition, 5936
  2. 1 2 International Chemical Safety Card 1152
  3. 1 2 3 4 5 6 NIOSH Pocket Guide to Chemical Hazards. "#0396". National Institute for Occupational Safety and Health (NIOSH).
  4. 1 2 "Methylal". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  5. Carey, Francis A.; Sundberg, Richard J. (2007). Advanced organic chemistry (5th ed.). New York: Springer. ISBN   9780387448978. OCLC   154040953.
  6. Shrestha, Krishna P.; Eckart, Sven; Elbaz, Ayman M.; Giri, Binod R.; Fritsche, Chris; Seidel, Lars; Roberts, William L.; Krause, Hartmut; Mauss, Fabian (2020). "A comprehensive kinetic model for dimethyl ether and dimethoxymethane oxidation and NO interaction utilizing experimental laminar flame speed measurements at elevated pressure and temperature". Combustion and Flame. 218: 57–74. doi:10.1016/j.combustflame.2020.04.016. hdl: 10754/662921 .
  7. Wuts, P. G. M.; Greene, T.W. (2006). Greene's Protective Groups in Organic Synthesis. NY: J. Wiley. doi:10.1002/0470053488. ISBN   9780470053485.
  8. Yardley, John P.; Fletcher, Horace (1976). "Introduction of the Methoxymethyl Ether Protecting Group". Synthesis. 1976 (04): 244–244. doi:10.1055/s-1976-24000.
  9. Berliner, Martin; Belecki., Katherine (2007). "Synthesis of alpha-Halo Ethers from Symmetric Acetals and in situ Methoxymethylation of an Alcohol". Organic Syntheses. 84: 102. doi: 10.15227/orgsyn.084.0102 .