Alkyl nitrites

Alkyl nitrites are a group of chemical compounds based upon the molecular structure R-ONO. Formally they are alkyl esters of nitrous acid. They are distinct from nitro compounds (R-NO2).

This article is about alkyl nitrites as a laboratory reagent. For their use in medicine and as a recreational drug, see Poppers.
alkyl nitrites

The first few members of the series are volatile liquids; methyl nitrite and ethyl nitrite are gaseous at room temperature and pressure. The compounds have a distinctive fruity odor. Another frequently encountered nitrite is amyl nitrite (3-methylbutyl nitrite).

Alkyl nitrites were initially, and largely still are, used as medications and chemical reagents, a practice which began in the late 19th century. In their use as medicine, they are often inhaled for relief of angina and other heart-related symptoms of disease. However, when referred to as "poppers", alkyl nitrites represent recreational drugs.

Synthesis and properties
Addiction experts in psychiatry, chemistry, pharmacology, forensic science, epidemiology, and the police and legal services engaged in delphic analysis regarding 20 popular recreational drugs. Alkyl nitrites were ranked 20th social and physical harm, and 18th in dependence.[1]

Organic nitrites are prepared from alcohols and sodium nitrite in sulfuric acid solution. They decompose slowly on standing, the decomposition products being oxides of nitrogen, water, the alcohol, and polymerization products of the aldehyde.[2] They are also prone to undergo homolytic cleavage to form alkyl radicals, the nitrite C–O bond being very weak (on the order of 40–50 kcal ⋅ mol−1).

Reactions

An isolated but classic example of the use of alkyl nitrites can be found in Woodward and Doering's quinine total synthesis:[10]

for which they proposed this reaction mechanism:

Medical use

Antidote to cyanide poisoning

Amyl nitrite is used medically as an antidote to cyanide poisoning,[11] The light alkyl nitrites cause the formation of methemoglobin wherein, as an effective antidote to cyanide poisoning, the methemoglobin combines with the cyanide to form nontoxic cyanmethemoglobin. First responders typically carry a cyanide poison kit containing amyl nitrite.

References
  1. Nutt, D; King, LA; Saulsbury, W; Blakemore, C (24 March 2007). "Development of a rational scale to assess the harm of drugs of potential misuse". Lancet. 369 (9566): 1047–53. doi:10.1016/s0140-6736(07)60464-4. PMID 17382831.
  2. n-butyl nitrite Organic Syntheses, Coll. Vol. 2, p.108 (1943); Vol. 16, p.7 (1936). http://www.orgsynth.org/orgsyn/prep.asp?prep=cv2p0108 Link
  3. Chemoselective Nitration of Phenols with tert-Butyl Nitrite in Solution and on Solid Support Organic Letters, Coll. Vol 11, p.4172-4175 (2009)
  4. Chemoselective Nitration of Aromatic Sulfonamides with tert-Butyl Nitrite Chemical Communications, doi:10.1039/C2CC37481A
  5. Cupferron Organic Syntheses, Coll. Vol. 1, p.177 (1941); Vol. 4, p.19 (1925) Link
  6. 2-Pyrrolidinemethanol, α,α-diphenyl-, (±)- Organic Syntheses, Coll. Vol. 6, p.542 (1988); Vol. 58, p.113 (1978) Link
  7. Dimethylglyoxime Organic Syntheses, Coll. Vol. 2, p.204 (1943); Vol. 10, p.22 (1930) Link
  8. Glyoxylyl chloride, phenyl-, oxime Organic Syntheses, Coll. Vol. 3, p.191 (1955); Vol. 24, p.25 (1944) Link
  9. [Benzeneacetonitrile, α-(1,1-dimethylethoxy)carbonylcarbonyl]oxy]imino]-] Organic Syntheses, Coll. Vol. 6, p.199 (1988); Vol. 59, p.95 (1979) Link
  10. The Total Synthesis of Quinine R. B. Woodward and W. E. Doering J. Am. Chem. Soc.; 1945; 67(5) pp 860 - 874; doi:10.1021/ja01221a051
  11. "Amyl Nitrite". Medsafe. New Zealand Medicines and Medical Devices Safety Authority. 2000-05-18. Archived from the original on 2006-11-11. Retrieved 2007-03-15.
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