Back to results
US 2010/0160695 A1Published application
Process for the synthesis of dihalodinitrotoluene
AssigneeE. I. Du Pont de Nemours and Company
InventorJOACHIM C. RITTER
Life of this patent
Estimating the term…
Abstract
An improved process is provided for the preparation of 2,6-dihalo-3,5-dinitrotoluene by the nitration of 2,6-dihalotoluene. The direct isolation of highly pure 2,6-dihalo-3,5-dinitrotoluene is accomplished without a water or ice quench, by providing at least one equivalent of SO3 during the reaction, slow crystallization, and isolation of product from a cold crystal slurry.
Claims10
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.
12 more elements
Dependencies are inferred from the claim text.