What is Hexamine?

Hexamine is an organic, heterocyclic chemical compound. Heterocyclic organic compounds are composed of at least one atom of carbon bound to at least one other element, such as oxygen or sulfur. The atoms are arranged in a ring structure. Hexamine goes by several other names, including methenamine, urotropine, and hexamethylenetetramine. Among other applications, hexamine is used as an antibiotic.

The reaction of formaldehyde and ammonia yields the crystalline hexamine. Its molecular formula is C₆H₁₂₄. Particles of hexamine tend to range in size from 80 to 800 micrometers; a strand of human hair is about 100 micrometers wide. It is soluble in water and in most organic substances, and it has a cage-like structure.

Medical professionals use hexamine as an antibiotic to treat urinary tract infections. The specific medication used is called methenamine hippurate. It is also used for the suppression of bacteruria in patients who have neurological diseases. In acidic urine, methenamine hydrolyzes into ammonia and formaldehyde, a nonspecific antibiotic. As this reaction is activated by acid in the urine, methenamine is often ineffective as an antibiotic in those whose urine is not acidic.

Hexamine is also the primary ingredient in Esbit® fuel tablets. These fuel tablets have a very high energy density, burn smokelessly, leave no ashes, and do not liquefy. They are traditionally used for cooking purposes by campers and military organizations. Esbit® fuel tablets are very lightweight and portable, but the heat they produce is difficult to control, and the fumes it produces are noxious. Some people are allergic to the compound, which can be absorbed through the skin.

Organic chemists use hexamine as a reagent in several chemical reactions. It is consumed in the formation of arenes, the conversion of benzyl halides to aldehydes, and the synthesis of amines from alkyl halides. Such reactions are quite complex and are often used for teaching purposes in organic chemistry courses. Often, they are used for purposes of chemical analysis to determine the identity of an unknown solute in a solution.

With its many purposes, hexamine is a very useful compound. For medical purposes, it is typically referred to as methenamine, while those who use it commercially refer to it by its usual name. Many United States and European drug companies produce and sell the compound for both medical and commercial uses. In addition to its common antibiotic and heating uses, it is also used in textile and rubber adhesives, in the photography industry, in the explosives industry, as a protein modifier, and in the production of deodorants and hair products.