Abstract:
Process for preparing dinitrotoluene by reacting toluene with concentrated nitric acid. The process reacts toluene with a large excess of concentrated nitric acid at selected conditions to produce a product which has substantially reduced by-product content.
Abstract:
Described herein is a continuous one pot process for the production of dinitrotoluene by: a) reacting toluene with concentrated nitric acid to produce a product mixture containing dinitrotoluene, unreacted nitric acid and water; b) then mixing the product mixture from step (a) with a substantially dehydrated molten nitrate salt; c) then adding additional nitric acid to the mixture of step (b); d) then separating nitric acid from the mixture from step c) in the form of a vapor to form a two phase liquid mixture; e) then separating the dinitrotoluene phase from the liquid hydrated salt phase; f) then treating the acid vapor from step d) and the hydrated salt-liquid phase of step (e) to separate and concentrate nitric acid for recycle to step (a); g) dehydrating the nitrate salt solution; and h) recycling the dehydrated nitrate salt to step (b).
Abstract:
A process for producing aromatic nitro compound which comprises nitrating an aromatic compound by blowing oxygen or air containing a nitrogen oxide and ozone into a solution or suspension thereof in an organohalogen solvent. The use of the oxygen or air containing a nitrogen oxide and ozone as the nitrating agent makes it possible to produce an aromatic nitro compound under mild conditions without using any inorganic acid and to remove various troubles accompanying the use of an inorganic acid in the conventional production process.
Abstract:
The invention provides a fluorinated aromatic sulfonic acid catalyst in which sulfonic acid groups and aryl groups substituted by fluorine atoms or fluoroalkyl groups are bound to a matrix selected from the group consisting of polysiloxane and inorganic base material. This catalyst can be produced by introducing sulfonic acid groups and aryl groups substituted by fluorine atoms or fluoroalkyl groups into the above-described matrix. This catalyst is used in various acid-catalyzed reactions such as esterification, acylation, nitration, alkylation, etherification, etc., particularly acid-catalyzed reactions in the presence of water to show a high acid catalysis activity. In addition, since this catalyst is solid, its handling is so easy that recovery and reuse thereof is easy.
Abstract:
Aromatic nitration reactions and, more specifically, a process for nitrating toluene to dinitrotoluene or benzene to mononitrobenzene. Since mononitrobenzene is useful in producing MDI and since dinitrotoluene is useful as an intermediate in producing TDI, new processes for the selective manufacture of these intermediates would be highly desirable to the polyisocyanate manufacturing community.
Abstract:
This invention relates to the nitration of benzene or toluene, and more specifically to such a reaction in a molten nitrate salt medium. The molten salt medium is selected from the group consisting of molten nitrate salts of sodium, potassium, lithium, and mixtures thereof. The reaction is conducted in the vapor phase at a reaction temperature of between about 150 DEG C and about 250 DEG C and at a reaction pressure of between about 100 mm of Hg and about one atmosphere for a reaction time not exceeding one hour.
Abstract:
A method of nitrating resorcinol which is selective for the production of the 4,6-dinitroresorcinol isomer. A resorcinol-based starting material is admixed with a nitrating solution from which substantially all nitrogen dioxide and nitrous has been removed. The nitrating solution contains white fuming nitric acid, a nitrosonium ion control agent such as urea, and, optionally, concentrated sulfuric acid. The 4,6-dinitroresorcinol isomer is provided in yields of about 65-85 % with minimal production of undesirable side products.