Urea and Thiocarbamides

Urea can be considered as the product that the two hydroxyls of carbonic acid (HO CO OH) are substituted by two aminos. 

According to Waler, the synthetic reaction of urea is given by the following  

There exist automers of urea and thiocarbamide. The automers of urea and thiocarbamide can be seen as follows  

Thiocarbamide is an important reducing agent in chemical analysis. The reduction reaction of thiocarbamide can be expressed as follows  

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