This MedLibrary.org supplementary page on Meta-chloroperoxybenzoic acid is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:
Related Sponsors
| Meta-Chloroperoxybenzoic acid | |
|---|---|
 |
|
 |
|
| IUPAC name | 3-chloroperoxybenzoic acid |
| Other names | meta-chloroperoxybenzoic acid;
m-chloroperoxybenzoic acid; meta-chloroperbenzoic acid; 3-chloroperbenzoic acid; mCPBA |
| Identifiers | |
| CAS number | [937-14-4] |
| RTECS number | SD9470000 |
| SMILES |
|
| Properties | |
| Molecular formula | C7H5ClO3 |
| Molar mass | 172.57 g/mol |
| Appearance | White powder |
| Melting point |
92 - 94 °C, decomposes |
| Acidity (pKa) | 7.57 |
| Hazards | |
| Main hazards | Oxidizing, corrosive |
| R-phrases | R7 R22 R34 |
| S-phrases | S17 S26 S36/37/39 S45 |
| Related compounds | |
| Related compounds | peroxyacetic acid; peroxybenzoic acid |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references |
|
meta-Chloroperoxybenzoic acid (mCPBA) is a peroxycarboxylic acid used widely as an oxidant in organic synthesis. mCPBA is often preferred to other peroxy acids because of its relative ease of handling. The main areas of use are the conversion of ketones to esters (Baeyer-Villiger oxidation), epoxidation of alkenes, oxidation of sulfides to sulfoxides and sulfones, and oxidation of amines to produce amine oxides.[1] mCPBA is a strong oxidizing agent that may cause fire upon contact with flammable material.
Contents |
Preparation
mCPBA can be prepared by reacting m-chlorobenzoyl chloride with hydrogen peroxide in the presence of magnesium sulfate, aqueous sodium hydroxide, and dioxane, followed by acidification.[2]
Availability and purity
As a pure substance, m-CPBA can be detonated by shock or by sparks. It is therefore sold commercially as a much more stable mixture that is less than 72% m-CPBA, with the balance made up of m-chlorobenzoic acid (10%) and water.[1] The peracid can be purified by washing the commercial material with a slightly basic buffer solution and then drying.[3] Peracids are generally slightly less acidic than their carboxylic acid counterparts, so one can extract the acid impurity by careful control of pH. The purified material is reasonably stable against decomposition if stored at low temperatures in a plastic container.
In reactions where the exact amount of m-CPBA must be controlled, a sample can be titrated to determine the exact amount of active oxidant.
Epoxidation example
The following reaction shows the reaction of cyclohexene with mCPBA to give an epoxide; the reaction mechanism is not shown. The epoxidation mechanism is concerted: the cis or trans geometry of the alkene starting material is retained in the epoxide ring of the product.
References
- ^ a b "3-Chloroperoxybenzoic acid". Organic Chemistry Portal.
- ^ Richard N. McDonald, Richard N. Steppel, and James E. Dorsey (1988). "m-Chloroperbenzoic Acid". Org. Synth.; Coll. Vol. 6: 276.
- ^ (1996) Purification of Laboratory Chemicals, 4th ed., Oxford: Butterworth-Heinemann, 145. ISBN 0750637617.
Wikipedia content modification information:
- This page was last modified on 28 August 2008, at 14:25.
Wikipedia Authorship and Review
Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.
Wikipedia Usage Guidelines
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Meta-chloroperoxybenzoic acid".
The URL for this specific entry is:
All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.