Process for the preparation of nitrated aromatics and mixtures thereof

Abstract

A process for the preparation of mononitroaromatics and dinitroaromatics, in which a hydrate melt of at least one metal nitrate M(NO 3 ) 3 is used as a nitrating medium, it being possible for M to be the metals Fe, Cr, Y, La, Ce, Al, Bi and In, and the metal nitrate having a water content of from 4 to 9 mol of water per M(NO 3 ) 3 , leads to simplifications of the process and improved yields.

1 . A process comprising:
 reacting a hydrate melt with an aromatic compound,   wherein:   the hydrate melt comprises at least one metal nitrate M(NO 3 ) 3 , which acts used as a nitrating medium;   M is a metal selected from the group consisting of Fe, Cr, Y, La, Ce, Al, Bi, and In; and   the at least one metal nitrate has a water content of from 4 to 9 mol of water per M(NO 3 ) 3 .   
     
     
         2 . The process of  claim 1 , wherein said process provides at least one of mononitrobenzene, mononitrotoluene, and dinitrotoluene. 
     
     
         3 . The process of  claim 1 , wherein the process is carried out in a temperature range from 30° C. to 200° C. 
     
     
         4 . The process of  claim 1 , wherein M is at least one selected from the group consisting of Fe, Cr, Bi and In. 
     
     
         5 . The process of  claim 1 , wherein the hydrate melt further comprises at least one additional component selected from the group consisting of nitric acid, a nitrate with a metal of higher valency, and a nitrate with a metal of lower valency. 
     
     
         6 . The process of  claim 1 , wherein the hydrate melt further comprises additional nitric acid added to the hydrate melt in the form of a 20 to 100% strength aqueous solution of HNO 3 , which is produced by reaction of the hydrate melt with gaseous or liquid nitrogen dioxide or by addition of at least one other acid. 
     
     
         7 . The process of  claim 1 , wherein nitration is affected by removing water of reaction during or after the reaction, and wherein a nitrate consumed is replenished by addition of at least one oxidant selected from the group consisting of nitric acid, NO, and NO 2  with or without addition of O 2 . 
     
     
         8 . The process of  claim 1 , wherein a content of TNT and a content of at least one nitrocresol in the reaction product are, in each case, less than 100 ppm. 
     
     
         9 . The process of  claim 1 , wherein nitration is affected by removing water of reaction during and after the reaction, and wherein a nitrate consumed is replenished by addition of at least one oxidant selected from the group consisting of nitric acid, NO, and NO 2 , with or without addition of O 2 .