Bromoacetic acid

  • Bromoethane acid
  • Monobromoacetic

White to pale yellow solid with a pungent odor

Fixed

1.93 g · cm -3

46-49 ° C

208 ° C

15,8 Pa ( 25 ° C)

2.89 (25 ° C)

Soluble in water ( 93.8 g · l -1)

1.4804 ( 50 ° C)

Risk

  • 50 mg · kg -1 ( LD50, rat, oral)
  • 59.9 mg · kg -1 ( LD50, Rabbit, transdermal)

Template: Infobox chemical / molecular formula search available

Bromoacetic acid (also monobromoacetic acid ) is a derivative of acetic acid in which a hydrogen atom of the methyl group is replaced by a bromine atom. Their salts are referred to as (mono) Bromacetate.

Representation

The presentation takes place by reaction of chloroacetic acid with potassium bromide ( nucleophilic substitution):

Properties

Bromoacetic acid forms colorless crystals with a pungent odor, melting 46-49 ° C and dissolve easily in water, ethanol, diethyl ether and other organic solvents. The aqueous solution is strongly acidic, much stronger acid than acetic acid. The reason for this is to stabilize the anion by means of the right electronegative bromine atom: It acts electron withdrawing and distributed ( delocalized ), the negative charge of the anion throughout the molecule. The anion is formed therefore lighter than the corresponding anion of acetic acid. In aqueous solution of bromoacetic acid forms with water to form hydronium ions and anions bromoacetate.

Use

Bromoacetic acid is the starting material for various syntheses, such as pesticides or drugs. Direct application was bromoacetic acid as a food preservative. This application, however, is now illegal in most states. Bromoacetic acid is strong alkylating and has an inhibitory effect on enzymes with SH, OH or NH 2 groups in the active site. They came earlier mainly in sweet French wines. In the 1980s there were in the Federal Republic of Germany a scandal because of the prohibited use of bromoacetic acid as a preservative in beer.

Volatile esters of bromoacetic acids are used as tear gas. They are irritating to the respiratory system and the eyes and can be harmful for it. At higher concentrations, they are caustic and may cause permanent damage to the eyes. They may not be used by children and are therefore prohibited as a joke article (see Bedarfsgegenständeverordnung ).

Safety

Bromoacetic acid and its solutions are highly caustic and toxic.

CAS registry number PubChem Vapor pressure Dangerous Substances Directive (67/548/EEC) CRC Handbook of Chemistry and Physics
148019
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