Oxazolone is a chemical compound and

functional group In organic chemistry, a functional group is any substituent or moiety (chemistry), moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions r ...

, with the molecular formula C₃H₃NO₂. It was named in-line with the

Hantzsch–Widman nomenclature In organic chemistry, Hantzsch–Widman nomenclature, also called the extended Hantzsch–Widman system (named for Arthur Rudolf Hantzsch and ), is a type of systematic chemical nomenclature used for naming heterocyclic parent hydrides having no m ...

and is part of a large family of

oxazole Oxazole is the parent compound for a vast class of heterocyclic compound, heterocyclic aromatic organic compounds. These are azoles with an oxygen and a nitrogen separated by one carbon. Oxazoles are aromatic compounds but less so than the thiaz ...

based compounds. There are a total of 5

structural isomer In chemistry, a structural isomer (or constitutional isomer in the IUPAC nomenclature) of a compound is a compound that contains the same number and type of atoms, but with a different connectivity (i.e. arrangement of bonds) between them. The ...

s of oxazolone; 3 according to the location of the carbonyl group and 2 more according to the location of the double bond C=X (with X= N or C): *2-(3''H'')oxazolone *2-(5''H'')oxazolone *4-(5''H'')-oxazolone *5-(2''H'')-oxazolone *5-(4''H'')-oxazolone Oxazolones

The 4-oxazolone motif, which is also formally a

lactam A lactam is a Cyclic compound, cyclic amide, formally derived from an amino alkanoic acid through cyclization reactions. The term is a portmanteau of the words ''lactone'' + ''amide''. Nomenclature Greek_alphabet#Letters, Greek prefixes in alpha ...

, is present in a number of drugs (

fenozolone Fenozolone (Ordinator) was developed by Laboratoires Dausse in the 1960s and is a psychostimulant related to pemoline. See also * 4-Methylaminorex * Aminorex * Clominorex * Cyclazodone * Fluminorex * Pemoline * Thozalinone Thozalinone (Un ...

thozalinone Thozalinone (United States Adopted Name, USAN) (brand name Stimsen; former developmental code name CL-39808) is a psychostimulant that has been used as an antidepressant in Europe. It has also been clinical trial, trialed as an anorectic. Thozal ...

cyclazodone Cyclazodone is a centrally acting stimulant Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of drugs that increase alertness. They are used for various purposes, suc ...

reclazepam Reclazepam is a drug which is a benzodiazepine derivative. It has sedative and anxiolytic effects similar to those produced by other benzodiazepine derivatives, and has a short duration of action. See also *Benzodiazepine Benzodiazepines ...

etc.). Substituted 5-oxazolones may also be regarded as the cyclization products of ''N''-

acyl In chemistry, an acyl group is a moiety derived by the removal of one or more hydroxyl groups from an oxoacid, including inorganic acids. It contains a double-bonded oxygen atom and an organyl group () or hydrogen in the case of formyl grou ...

α-

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

s, making them

lactones Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated. Lactones are formed by lactonization, the intramolecular esterification of the corre ...

, and are sometimes referred to as azlactones.

References

{{reflist Oxazolones