METHOD OF PREPARING DINITROTOLUENE Russian patent published in 1998 - IPC

FIELD: chemical industry. SUBSTANCE: present invention describes method of nitration of toluene to prepare dinitrotoluene by liquid phase nitration reaction. Anhydrous nitric acid is reacted with toluene in reactor at reaction temperature ranging from 20 to 30 C during reaction period of at least 15 minutes at nitric acid to water to toluene molar ratio of 10:1 and 15:1. Said reaction is carried out without using sulfuric acid and any aprotic dipolar solvent throughout reaction period and without using any aprotic dipolar solvent to stop reaction for preparation of said dinitrotoluene in admixture of products free from nitrocresol impurity. Mixture of products is subsequently distilled in vacuum without using any aprotic dipolar solvent to remove unreacted nitric acid from said mixture of products to give dinitrotoluene. EFFECT: more efficient preparation method. 8 cl, 1 tbl