3-Chloroperoxybenzoic acid

Description

m-CPBA is a peroxycarboxylic acid that is commonly used as an oxidizing agent. It is usually available in <77% form because pure m-CPBA is shock sensitive (potentially explosive). It usually consists of ~10% m-chlorobenzoic acid and the remainder is H2O.

Chemical properties

White moist powder

The Uses of 3-Chloroperoxybenzoic acid

3-Chloroperoxybenzoic acid is a strong oxidizing agent used in the oxidation reactions such as aldehydes and ketones to esters (Bayer-Villiger-Oxidation), olefines to epoxides, sulfides to sulfoxides and sulfones, and amines to nitroalkanes, N-oxides.

The Uses of 3-Chloroperoxybenzoic acid

The SM (1 g, 3 mmol) was suspended in acetone (10 mL), cooled to 0 C, and treated portionwise with mCPBA (2.59 g, 15 mmol). The suspension became a clear solution after stirring at 0 C for 30 min. The reaction mixture was then allowed to warm up slowly to RT and was stirred for 5 h. Saturated aq NaHCO3 (50 mL) was added to give a mixture with pH 8. The resulting mixture was extracted with EtOAc (3 x 10 mL). The combined organics were washed with brine, dried (Na2SO4), and concentrated to provide crude product. [1 g]

The Uses of 3-Chloroperoxybenzoic acid

Effective oxidant for epoxidizing di-, tri-, and tetra-substituted olefins.

What are the applications of Application

3-Chloroperbenzoic acid is a reagent for the epoxidation of olefins

Definition

ChEBI: 3-chloroperbenzoic acid is a peroxy acid and a member of monochlorobenzenes.

Reactions

3-Chloroperoxybenzoic acid (MCPBA) is one of the most popular oxidation reagent in organic synthesis, because of its outstanding performance in terms of:
reactivity, combined with reducing the number of reaction steps in classical synthetic routes,
regio- and stereoselectivity,
protection of functional groups mostly not required,
high purity and yields.
Its literature covers a huge area of different syntheses and below reaction equations just can be a brief overview of its interesting applications:

Synthesis Reference(s)

Synthetic Communications, 19, p. 1271, 1989 DOI: 10.1080/00397918908054534

General Description

3-Chloroperoxybenzoic acid is sensitive to heat. Storage of 3-Chloroperoxybenzoic acid must be done so with stringent temperature control measures. It's explosion hazard is also mitigated by mixing the peroxide in a solvent slurry.

Reactivity Profile

May explode from heat, shock, friction or contamination. May ignite combustibles (wood, paper, oil, clothing, etc.). May be ignited by heat, sparks or flames.

Purification Methods

Recrystallise MCPBA from CH2Cl2 [Traylor & Mikztal J Am Chem Soc 109 2770 1987]. Peracid of 99+% purity can be obtained by washing commercial 85% material with phosphate buffer pH 7.5 and drying the residue under reduced pressure. Alternatively the peracid can be freed from m-chlorobenzoic acid by dissolving 50g/L of *benzene and washing with an aqueous solution buffered at pH 7.4 (NaH2PO4/NaOH) (5 x 100mL). The organic layer is dried over MgSO4 and carefully evaporated under vacuum. Necessary care should be taken in case of EXPLOSION. The solid is recrystallised twice from CH2Cl2/Et2O and stored at 0o in a plastic container as glass catalyses the decomposition of the peracid. The acid is assayed iodometrically. [Schwartz & Blumbrgs J Org Chem 29 1976 1964, Bortolini et al. J Org Chem 52 5093 1987, McDonald et al. Org Synth Coll Vol VI 276 1988, Beilstein 9 IV 972.]