What Is Amyl Nitrite?
Amyl nitrite is an organic compound, an ester of nitrite, with the molecular formula C5H11NO2. While amyl nitrite typically refers to a group of isomeric nitrite esters, this section focuses on both n-amyl nitrite and isoamyl nitrite, each having a molecular weight of 117.15.
1. N-Amyl Nitrite (N-Pentyl Nitrite)
n-Amyl nitrite, or Pentyl Nitrite, is a clear yellowish liquid at room temperature, with a boiling point of 104-105 °C. It has a sweet smell and a density of 0.836 g/mL. This compound decomposes upon contact with water, is practically insoluble (solubility 3.97 g/L), but is miscible with organic solvents like ethanol, ether, and chloroform. Its CAS registration number is 463-04-7.
2. Isoamyl Nitrite (Isopentyl Nitrite)
Isoamyl nitrite, also known as Isopentyl nitrite, is a clear yellowish liquid with a fruity odor and a density of 0.875 g/mL. It boils at 99 °C and is practically insoluble in water, but miscible with chloroform, ethanol, and ether. The flash point of isoamyl nitrite is 3 °C.
Uses of Amyl Nitrite
Isoamyl nitrite is used in cardiac medications for conditions like angina pectoris and as an antidote for cyanide poisoning. It is also used as an inhalant due to its vaporizing tendency and sometimes as an antidote for hydrogen sulfide poisoning. A small amount can be absorbed onto a piece of cloth and inhaled to alleviate seizures immediately.
Principle of Amyl Nitrite
The principles of amyl nitrite are rooted in its chemical properties. Amyl nitrite is synthesized through the esterification of amyl alcohol with nitric acid. It’s used in organic chemistry for diazotization of primary amines and N-nitrosation of secondary amines. A typical application is in the Sandmeyer reaction, involving halogen substitution in aromatic rings.
2. Principle of Cyanide Detoxification by Isoamyl Nitrite
Isoamyl nitrite works in cyanide detoxification by oxidizing the Fe2+ in hemoglobin to Fe3+ methemoglobin. This inhibits the binding of cyanide to cytochrome oxidase. Additionally, when administered with sodium thiosulfate, it helps convert cyanogen to thiocyanate, aiding detoxification.
Types of Amyl Nitrite
Both n-amyl nitrite and isoamyl nitrite are sold under the name amyl nitrite. However, they can be distinguished in chemical reagents by their aliases or CAS registry numbers. Drugs labeled as amyl nitrite predominantly contain isoamyl nitrite.