Dibromoacetic acid

Dibromoacetic acid [631-64-1] (Br2CHCOOH), mol wt 217.8, C2H2Br202, mp 48°C, bp 232—234°C (decomposition), is soluble in water and ethyl alcohol. It is prepared by adding bromine to boiling acetic acid, or by oxidi2ing tribromoethene [598-16-3] with peracetic acid. 

Haloacetic acids dichloroacetic acid (zero) trichloroacetic acid (0.3 mg/L). Monochloroacetic acid, bromoacetic acid, and dibromoacetic acid are regulated with this group but have no MCLGs. 

CHBr2COOH (c). Pickering10 measured the heat of solution of dibromoacetic acid. 

Tritium in the acetyl moiety 175b has been obtained using, in a similar sequence of reactions, dibromoacetic acid and subsequent catalytic halogen-tritium exchange (equation 88). 

A reaction of dibromoacetic acid with different aldehydes promoted by Sml2, followed by an elimination reaction also promoted by samarium diiodide, affords ( > ,/l-unsaturalcd carboxylic acids with total stereoselectivity (Scheme 8).42 A mecha- (g) nism that involves chelation of the Sm(III) centre with the oxygen atom of the alcohol group through a six-membered chair-like transition state has been described. 

Monobromoacetic acid Dibromoacetic acid Bromochloroacetic acid Haloacetic acids (total) Dichloroacetonitrile 1,1 Dichloropropanone Chloropicrin Glyoxal Chloroform Bromoform... 

Formation of iodine is detected tens of picoseconds after the irradiation of CH2ICH2I or CF2ICF2I in acetonitrile solution. In a continuation of their work on 1,1-dihalo compounds, Phillips and his group have investigated the photochemical behaviour of 1,1-dibromoacetic acid. Irradiation provides evidence for the formation of the iso-dibromoacetic acid (120). This is akin to the observations with 1,1-diodomethane. The authors propose that this species (120) could exhibit carbenoid character. Laser flash photolysis of 1,2-dibro-moethane at 248 nm in water provides a source of bromine atoms. ""... 

A readily available formyl ester equivalent is ethyl dibromo- or dichloroacetate, or the free acid. For example xanthopterin, 2-aminopteridine-4,6(3/T,5/T)-dione, can be made in 65% yield via the intermediate dibromoacetamino compound, from 2,5,6-triaminopyrimidin-4(3//)-one and dibromoacetic acid.82... 

The tendency for -bromination is so strong that treating fatty acids with bromine in presence of halogen carriers (S, P, or I2) in a bomb tube leads to a ,a -dibromo acids dibromoacetic acid, for instance, is obtained from glacial acetic acid and bromine in the presence of sulfur at 150°.568... 

The decarboxylation affords dibromoacetic acid, but in the presence of bromine the end-product is tribromoacetic acid since bromine has no effect on the rate of reaction, and since dibromoacetic acid is not brominated under the reaction conditions, the carbanion mechanism is conclusively proved for this case. 

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