Urea is synthesized in the liver and is a nitrogen-containing metabolite excreted by mammals. This metabolic process is called urea cycle. Urea is the first organic compound obtained by artificial synthesis of inorganic substances.
Extended data
nature
Can react with acids to form salts. There is hydrolysis. The condensation reaction can be carried out at high temperature to produce biuret, biuret and cyanuric acid. Heat to 65438+/-060℃ for decomposition, and that generated ammonia gas is simultaneously convert into isocyanate. Because human urine contains this substance, it is named urea. Urea contains 46% nitrogen, which is the highest among solid nitrogen fertilizers.
Urea can be hydrolyzed to produce ammonia and carbon dioxide under the action of acid, alkali and enzyme (acid and alkali need to be heated). Unstable to heat, it will deamination into biuret when heated to 150~ 160℃. The reaction between copper sulfate and biuret is purple and can be used to identify urea. If heated rapidly, it will deamino and trimerize into a six-membered ring compound cyanuric acid. (Mechanism: first deamination to produce isocyanate (HN=C=O), and then trimerization. )
It can react with acetyl chloride or acetic anhydride to produce acetourea and diacetyl urea. Under the action of sodium ethoxide, it reacts with diethyl malonate to produce malonyl urea (also called barbituric acid, because it has certain acidity). Under the action of alkaline catalysts such as ammonia water, it can react with formaldehyde and condense to produce urea-formaldehyde resin.
Baidu encyclopedia-urea