Process for the production of hydrazoaromatics using a multi-phase system
AssigneeAir Products and Chemicals, Inc.
InventorCharles G. Coe
Life of this patent
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Abstract
A process is disclosed for the catalytic hydrogenation of nitro-alkylbenzenes to hydrazo-alkylbenzenes wherein the reaction is conducted in a two phase solution wherein one phase constitutes an aqueous alkaline base and a second organic phase constitutes a solvent mixture having a first solvent component which is a solvent for the starting reactant and the alkaline base and a second solvent component which lowers the solvent mixture dielectric constant below 25 and which solvent component is a solvent for the reaction product.
Claims17
In a process for catalytically hydrogenating a compound of the formula:
- ##STR2## where R is a lower alkyl having one to six carbons, to its hydrazo derivative product in the presence of a hydrogen atmosphere, a metal hydrogenation catalyst, and an alkaline base in aqueous solution, the improvement for enhancing the selectivity and yield of the hydrazo derivative product which comprises utilizing a solvent mixture which is inert to hydrogenation in which one solvent component is capable of solubilizing the compound and at least a portion of the alkaline base and another solvent component which is effective for maintaining the dielectric constant of the solvent mixture below 25 and capable of solubilizing the hydrazo derivative product.
In a process for catalytically hydrogenating o-nitrotoluene to o-hydrazotoluene in the presence of a hydrogen atmosphere, a noble metal hydrogenation catalyst, a quinone and an alkali metal hydroxide in aqueous solution, the improvement comprising conducting the reaction in a solvent mixture of ethanol and tetrahydrofuran and separating the o-hydrazotoluene product from the solvent by filtration of the noble metal catalyst from the solvent and dilution of the solvent with water to precipitate the o-hydrazotoluene product for separation.
In a process for catalytically hydrogenating o-nitrotoluene to o-hydrazotoluene in the presence of a hydrogen atmosphere, a noble metal hydrogenation catalyst, a quinone and an alkali metal hydroxide in aqueous solution, the improvement comprising conducting the reaction in a solvent mixture of methanol and tetrahydrofuran and separating the o-hydrazotoluene product from the solvent by filtration of the noble metal catalyst from the solvent and dilution of the solvent with water to precipitate the o-hydrazotoluene product for separation.
Dependencies are inferred from the claim text.