In chemistry, ureas are a group of organic compounds that possess the general formula (R2N)2CO, where R can represent hydrogen, alkyl, aryl, or other substituents.Under suitable conditions, such as in the presence of heat, urea can undergo decomposition to yield isocyanate, a chemical species that contains a carbon-nitrogen-oxygen functional group.Ureas that contain N-H bonds, including urea itself, can be readily alkylated by aldehydes.