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Alkyl nitrite

Inorganic chemistry, alkyl nitrites are a group of organic compounds based upon the molecular structure R−O−N=O, where R represents an alkyl group. Formally they are alkyl estersofnitrous acid. They are distinct from nitro compounds (R−NO₂).

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[edit]

Organic nitrites are prepared from alcohols and sodium nitriteinsulfuric acid solution. They decompose slowly on standing, the decomposition products being oxidesofnitrogen, water, the alcohol, and polymerization products of the aldehyde.^[1] 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[edit]

• tert-Butyl nitrite has been shown to be an effective reagent for the selective nitration of phenols^[2] and aryl sulfonamides^[3]
• n-Butyl nitrite and ammonia convert phenylhydroxylamine to its nitrosamine derivative cupferron.^[4] Likewise pyrrolidine is a substrate for ethyl nitrite.^[5]
• Alkyl nitrites are also used in the formation of oximes with the stronger carbon acids and acid or base catalysis for example in the reaction of 2-butanone, ethyl nitrite and hydrochloric acid forming the oxime,^[6] the similar reaction with phenacyl chloride,^[7] or the reaction of phenylacetonitrile with methyl nitrite and sodium hydroxide.^[8]

An isolated but classic example of the use of alkyl nitrites can be found in Woodward and Doering's quinine total synthesis:^[9]

for which they proposed this reaction mechanism:

References[edit]

External links[edit]

• Media related to Alkyl nitrites at Wikimedia Commons