The addition of acid will require from an hour to an hour and a half.
The stirring is then continued for half an hour longer without cooling; the mixture is allowed to stand over night in a separatory funnel; the lower layer of spent acid is drawn off; and the crude mononitrotoluene is weighed.
Slowly the temperature is raised to 110° C and keep at that temperature for 1 hour.
After nitration is complete the reaction flask is cooled to 80° C.
The trinitration in the laboratory is conveniently carried out without separating the 2,4-dinitrotoluene from the spent acid.
While the dinitration mixture is stirred actively at a temperature of about 90° C, 145 grams of fuming sulfuric acid (oleum containing 15% free sulfur trioxide) is added slowly by pouring from a beaker.
All the product is washed three or four times by agitating it vigorously with hot water under which it is melted.
After the last washing, the TNT is granulated by allowing it to cool slowly under hot water while the stirring is continued.
An efficient ruthenium-catalyzed synthesis of tri-substituted 1,3,5-triazinones from alcohols and guanylureas under mild conditions has been developed.
The scope of both the alcohols and guanylureas in the reaction is demonstrated.