Patent ID: 8003831
Filing Date: 2011-08-23
Classification: C07C

Abstract:
1. A process for preparing a 1,3-dihalo-4,6-dinitrobenzene comprising: (a) admixing a 1,3-dihalobenzene, which is represented by the structure of the following Formula (III): wherein each X is independently Cl or Br, with fuming nitric acid having a density of 1.54, sulfuric acid, and SO 3 to form a reaction mixture that is characterized by (i) a concentration of nitric acid therein that is in the range of about 2.0 to about 2.3 moles per mole of 1,3-dihalobenzene; (ii) a concentration of SO 3 therein that is in the range of about 1 to about 3 moles per mole of 1,3-dihalobenzene; (iii) a concentration of 1,3-dihalobenzene therein that is in the range of about 12 to about 24 weight percent; and (iv) a temperature of up to about 10° C. to about 40° C.; and (b) stirring the reaction mixture at a temperature of about 100° C. to about 120° C. for at least about 15 minutes to form a 1,3-dihalo-4,6-dinitrobenzene product, and (c) cooling the reaction to a temperature at which the 1,3-dihalo-4,6-dinitrobenzene product crystallizes.