Ethyl bromoacetate

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Ethyl bromoacetate
Skeletal formula of ethyl bromoacetate
Ball-and-stick model of ethyl bromoacetate
Identifiers
CAS number 105-36-2 YesY
PubChem 7748
ChemSpider 7462 YesY
ChEMBL CHEMBL1085948 YesY
RTECS number AF6000000
Jmol-3D images Image 1
Properties
Molecular formula C4H7BrO2
Molar mass 167.00 g mol−1
Appearance Colorless to yellow liquid[1]
Density 1.51 g/cm3
Melting point −38 °C (−36 °F; 235 K)[1]
Boiling point 158 °C (316 °F; 431 K)[1]
Solubility in water Insoluble
Hazards
EU classification Very toxic (T+), Powerful lachrymator, Extremely harmful,
R-phrases R26/27/28
S-phrases (S1/2), S7/9, S26, S45
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 4: Very short exposure could cause death or major residual injury. E.g., VX gas Reactivity code 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g., fluorine Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point 47 °C (117 °F; 320 K)[1]
Related compounds
Other anions Ethyl acetoacetate
Ethyl iodoacetate
Related esters Methyl bromoacetate
Related compounds Pepper spray
Chloropicrin
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Ethyl 2-bromoacetate is the chemical compound with the formula CH2BrCO2C2H5. It is the ethyl ester of bromoacetic acid and is prepared in two steps from acetic acid.[2] It is a lachrymator and has a fruity, pungent odor.[3] It is also a highly toxic alkylating agent and may be fatal if inhaled.

Applications[edit]

In World War I, ethyl bromoacetate was used as a lachrymatory agent and tear gas agent for chemical warfare under the German code Weisskreuz (White Cross), and later as odorant or warning agent in odorless, toxic gases. It is listed by the World Health Organization as a riot control agent, and was first employed for that purpose by French police in 1912.[4] The French may have employed gas grenades of this substance in 1914 during World War I. The German army then used this attack to justify their subsequent employment of chemical weapons in 1915.[5]

In organic synthesis, it is a versatile alkylating agent. Its major application involves the Reformatsky reaction, wherein it reacts with zinc to form a zinc enolate. The resulting BrZnCH2CO2Et condenses with carbonyl compounds to give a β-hydroxy-esters.

It is also the starting point for the preparation of several other reagents. For example, the related Wittig reagent (prepared by reaction with triphenylphosphine) is commonly used to prepare alpha,beta-unsaturated esters from carbonyl compounds such as benzaldehyde:[6]

Ethyl bromoacetate as the starting point for a Wittig reaction sequence


References[edit]

  1. ^ a b c d Chemicalland properties database
  2. ^ Natelson, S.; Gottfried, S. (1955), "Ethyl Bromoacetate", Org. Synth. ; Coll. Vol. 3: 381 
  3. ^ Criswell, DW; McClure, FL; Schaefer, R; Brower, KR (1980). "War gases as olfactory probes". Science 210 (4468): 425–6. doi:10.1126/science.6968976. PMID 6968976. 
  4. ^ Public health response to biological and chemical weapons, Chapter 3, Biological and Chemical agents, WHO Guidance]
  5. ^ Heller, Charles E. (September 1984). "Chemical Warfare in World War I: The American Experience, 1917-1918". Combat Studies Institute. Retrieved 2007-08-02. 
  6. ^ A student lab procedure for the Wittig sequence shown, only using the related methyl ester.

External links[edit]