The chemical compound amyl nitrite (or isoamyl nitrite) is a nitrite with chemical formula C5H11·ONO. It has a characteristic penetrating odour, and produces marked effects on the system when its vapour is inhaled. It acts as a vasodilator (expanding blood vessels and thus lowering blood pressure) and finds applications in medicine in the treatment of heart disease such as angina. It is one form of the recreational drug called poppers (see that article for information on its recreational use). The effects of amyl nitrite are thought to be due to the action of nitric oxide in the body.
Physical effects include headache, the face flushing, decrease in blood pressure, increase in pulse, dizziness and relaxation of involuntary muscles, especially the blood vessel walls and the anal sphincter. There are no withdrawal symptoms. Overdose symptoms include nausea, vomiting, badly decreased blood pressure and respiration, fainting, cold skin and possible circulatory collapse and death.
Amyl nitrite is a yellow-coloured liquid of specific gravity 0.877, boiling at about 95 to 96 degrees Celsius. It is insoluble in water, but dissolves readily in alcohol, ether, glacial acetic acid, chloroform, and benzene. It is prepared by passing nitrous fumes (from starch and concentrated nitric acid) into warm isoamyl alcohol, or by distilling a mixture of 26 parts of potassium nitrite in 15 parts of water with 30 parts of isoamyl alcohol in 30 parts of sulphuric acid. On heating with methyl alcohol, it is converted into isoamyl alcohol and methyl nitrite; a similar reaction takes place with ethyl alcohol, but the change is less complete. It is readily decomposed by nascent hydrogen, with the formation of ammonia and isoamyl alcohol; and on hydrolysis with caustic potash it forms potassium nitrite and isoamyl alcohol. When the liquid is dropped onto fused caustic potash, it forms potassium valerate.
