What Is Isobutyl Nitrite?
Isobutyl nitrite, a nitrite ester formed from nitrous acid and isobutanol, has the chemical formula C4H9NO2. Its CAS No. is 542-56-3. This compound is a clear, colorless liquid at room temperature with a molecular weight of 103.12, a boiling point of 152.6 °F (67 °C), and a density of 0.87 g/mL. It is slightly soluble in water, but tends to decompose, and is miscible with organic solvents like ether and ethanol. Notably, it is highly flammable with a low flash point of -5.8 °F (-21 °C).
Uses of Isobutyl Nitrite
Isobutyl nitrite is primarily used as an additive in air fresheners and as a raw material in the production of carboxymethylcellulose, agricultural chemicals, pharmaceuticals, and plasticizers. It also serves as an antidote for cyanide poisoning and as a vasodilator. Recognized as a ‘rush drug’, its manufacture, import, sale, and other uses are strictly regulated, and permitted only for medical purposes and other non-harmful applications.
Principle of Isobutyl Nitrite
The chemical properties of isobutyl nitrite include its synthesis through the esterification reaction of nitrous acid and isobutanol, a common process for nitrite esters. It is hydrolyzed in the presence of a base, reverting to the original alcohol and nitrite. Highly flammable, it decomposes in water and upon heating, produces nitrogen oxides (NOx). It should not be mixed with acids or oxides due to the risk of dangerous reactions.
2. Principle of Cyanide Detoxification With Isobutyl Nitrite
Isobutyl nitrite aids in cyanide detoxification by oxidizing the Fe2+ in heme iron to Fe3+ methemoglobin, which binds with cyanide ions (CN-) to form cyanomethemoglobin. This process prevents cyanide from binding to cytochrome oxidase and causing harm. Additionally, administering sodium thiosulfate helps convert dissociated cyanide to thiocyanate, further aiding detoxification.
Types of Isobutyl Nitrite
Isobutyl nitrite is a designated drug, strictly regulated for possession and use, and currently only sold as a synthetic organic chemical reagent for research and development. Regulations restrict its use to the diagnosis, treatment, or prevention of disease and other non-harmful purposes. It is available in 25 mL, 100 mL, and 500 mL volumes and must be stored at 32-50°F (0-10°C), away from light, moisture, and heat to prevent decomposition.