Patent ID: 8183418

Claim:
A process for preparing 2,6-dihalo-3,5-dinitrotoluene comprising the sequential steps: a) preparing a reaction mixture by combining fuming nitric acid; sulfuric acid; oleum or SO3; and 2,6-dihalotoluene (III) wherein each Z is independently Cl or Br; wherein (i) the concentration of nitric acid is about 2.0 to about 2.3 moles per mole of 2,6-dihalotoluene; (ii) the concentration of SO3 is about 1 to about 3 moles per mole of 2,6-dihalotoluene; and (iii) the concentration of 2,6-dihalotoluene in the reaction mixture is between about 12 and about 24 weight percent; wherein the temperature of the reaction mixture does not exceed 120° C.; b) optionally, heating the reaction mixture at a temperature not to exceed about 120° C., then cooling the reaction mixture or allowing it to cool; c) allowing reaction to proceed to completion with stirring at a temperature between about −10° C. and about 70° C.; and d) isolating the product 2,6-dihalo-3,5-dinitrotoluene from the reaction mixture at a temperature between about 0° C. and about 40° C., wherein isolating the product is achieved by filtration of the reaction mixture without water quenching.