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.
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.
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, 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

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. They are also prone to undergo homolytic cleavage to form alkyl radicals, the nitrite C-O bond being very weak.

Reactions

An isolated but classic example of the use of alkyl nitrites can be found in Woodward and Doering's quinine total synthesis:
for which they proposed this reaction mechanism:

Medical use

Antidote to cyanide poisoning

Amyl nitrite is used medically as an antidote to cyanide poisoning, 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.