New Process For the Preparation of 26 Dichloro-4 Nitrophenol

New Process For the Preparation of 26 Dichloro-4 Nitrophenol

The phenolic compound 26 dichloro-4 nitrophenol (also known as p-nitrophenol, p-nitrobenzene, and 2-chloro-4-nitrophenol) is a white to light yellow crystalline solid.26 dichloro-4 nitrophenol It is used in the manufacture of drugs, fungicides and dyes and to darken leather. Bioaccumulation of this compound rarely occurs in the aquatic environment. Several methods are available to remove this compound from wastewater. The most common is its degradation by nitrite-reducing bacteria. This method has been successfully used to treat wastewater from a tanning industry in Turkey, and it has also been applied to the removal of this compound in other industrialized countries. However, the application of this method has been limited by the availability of nitrite-reducing bacteria. The present invention relates to a novel process for the preparation of this compound which allows for the recovery of this substance in high yield and purity.

The new process for the preparation of this compound consists in practicing hydrogenation of dichloro-2,6-dichloro-4 nitrophenol at low temperature using a metal-based catalyst chosen from palladium and platinum in a solvent of diethylene glycol.26 dichloro-4 nitrophenol This hydrogenation reaction avoids loss of chlorine atoms by hydrodechlorination and prevents the formation of azo derivatives.

This synthesis process is performed in a reactor which comprises a first raw material storage tank group, a mixing kettle, a kettle-type reactor, a second raw material storage tank group, a tower-type reactor, and a distillation and purification tower.26 dichloro-4 nitrophenol The first raw material storage tank group is mixed with tetrachloroethylene and concentrated sulfuric acid, followed by a nitration reaction with nitric acid, and the resulting 2,6-dichloro-4-nitrophenol is subjected to reduction with hydrazine hydrate in the tower-type reactor. This reaction is conducted under a controlled atmosphere.

A chromatographic analysis of the reaction liquid reveals that the final product contains more than 99% of 2,6-dichloro-4-aminophenol.26 dichloro-4 nitrophenol The remaining traces are removed by distillation of the filtrate until a weight close to 460 g is reached. After addition of an equivalent quantity of water, a precipitate of 63 g of 2,6-dichloro-4-aminophenol is obtained, which after washing with water and drying represents a yield of 4.2%.

This newly developed method allows for the direct detection of halonitrophenols in environmental waters and wastewater, and is useful for the monitoring of potential disinfection byproducts in human sewage.26 dichloro-4 nitrophenol It can be used to assess the presence of these substances in drinking water and in surface and groundwater sources, as well as in wastewater. The method is simple, inexpensive, and easily applicable in laboratories. In addition, the sensitivity of this method is higher than that of other methods, making it suitable for real-time monitoring in industrial facilities. Moreover, it can detect the formation of halonitrophenols within hours. This is important because these compounds are emerging aromatic nitrogenous disinfection byproducts with high cytotoxicity and genotoxicity. This makes it necessary to control the formation of these halonitrophenols during UV disinfection processes in order to protect public health. This is especially true in arid regions where wastewater treatment plants are increasingly being used for the disinfection of drinking water.