Ethyl bromoacetate

Ethyl bromoacetate
Names
Preferred IUPAC name
Ethyl bromoacetate
Other names
Ethyl 2-bromoacetate
Bromoacetic acid, ethyl ester
Antol
Ethoxycarbonylmethyl bromide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.002.992
RTECS number AF6000000
UNII
Properties
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]
Insoluble
-82.8·10−6 cm3/mol
Hazards
Very toxic (T+), Powerful lachrymator, Extremely harmful,
R-phrases (outdated) R26/27/28
S-phrases (outdated) (S1/2), S7/9, S26, S45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
0
4
3
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 otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Ethyl 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

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]

References

  1. 1 2 3 4 Chemicalland properties database
  2. ↑ Natelson, S.; Gottfried, S. (1955). "Ethyl Bromoacetate". Org. Synth.; Coll. Vol., 3, p. 381
  3. ↑ Criswell, DW; McClure, FL; Schaefer, R; Brower, KR (1980). "War gases as olfactory probes". Science. 210 (4468): 425–6. PMID 6968976. doi:10.1126/science.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.
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