O-nitrophenol
Structural formula
Chemical Name: O-nitrophenol
Other Names: 2-nitrophenol, O-hydroxynitrobenzene
Formula: C6H5NO3
Molecular weight: 139
CAS No.: 88-75-5
EINECS: 201-857-5
Transport number of dangerous goods: UN 1663
Specifications
1. Appearance: Light yellow crystal powder
2. Melting point: 43-47℃
3. Solubility: soluble in ethanol, ether, benzene, carbon disulfide, caustic soda and hot water, slightly soluble in cold water, volatile with steam.
Synthesis Method
1.Hydrolysis method: o-nitrochlorobenzene is hydrolyzed and acidified by sodium hydroxide solution. Add 1850-1950 l of 76-80 g / L sodium hydroxide solution into the hydrolysis pot, and then add 250 kg of fused o-nitrochlorobenzene. When it is heated to 140-150 ℃ and the pressure is about 0.45MPa, keep it for 2.5h, then raise it to 153-155 ℃ and the pressure is about 0.53mpa, and keep it for 3h. After the reaction, it was cooled to 60 ℃. Add 1000L water and 60L concentrated sulfuric acid into the crystallizer in advance, then press in the hydrolysate mentioned above, and slowly add sulfuric acid until Congo red test paper turns purple, then add ice to cool to 30 ℃, stir, filter, and shake off the mother liquor with centrifuge to obtain 210kg o-nitrophenol with content of about 90%. The yield is about 90%. Another preparation method is nitration of phenol into a mixture of o-nitrophenol and p-nitrophenol, and then distillation of o-nitrophenol with water vapor. The nitrification was carried out at 15-23 ℃ and the maximum temperature should not exceed 25 ℃.
2.Phenol nitration. Phenol is nitrated by nitric acid to form a mixture of o-nitrophenol and p-nitrophenol, and then separated by steam distillation.
Application
It can be used as the intermediate of organic synthesis such as medicine, dyestuff, rubber assistant and photosensitive material. It can also be used as a monochromatic pH indicator.
Storage method
Sealed store in a cool and ventilated warehouse. Keep away from fire and heat source. It should be stored separately from oxidant, reductant, alkali and edible chemicals, and mixed storage should be avoided. Explosion proof lighting and ventilation facilities are adopted. It is forbidden to use mechanical equipment and tools that are easy to produce sparks. The storage area should be equipped with suitable materials to contain the leakage, away from the heat source, spark and flame flammable and explosive areas.
Attentions
Closed operation to provide adequate local exhaust. Operators must be specially trained and strictly abide by the operating procedures. It is suggested that operators should wear self-priming filter type dust mask, chemical safety glasses, anti poison penetration work clothes and rubber gloves. Keep away from fire and heat source. No smoking in the workplace. Use explosion-proof ventilation system and equipment. Avoid dust. Avoid contact with oxidant, reducing agent and alkali. When carrying, it should be loaded and unloaded lightly to prevent the package and container from being damaged. Fire fighting equipment of corresponding variety and quantity and leakage emergency treatment equipment shall be provided. Empty containers may contain harmful substances.
