What Is Phenylhydrazine?
Phenylhydrazine is an organic compound classified as a hydrazine derivative.
Its chemical formula is C6H8N2, and one of the hydrogen atoms in the benzene ring is substituted with hydrazine (-NH-NH2).
Its molecular weight is 108.14, the melting point is 19.5℃, and the boiling point is 243.5℃ (decomposition). At room temperature, it is a colorless to yellow oily liquid or crystal, but turns dark red when exposed to air and light. Its density is 1.0978 g/cm3. The substance is slightly soluble in ethanol and acetone and insoluble in water.
Exposure to humans may cause contact dermatitis and acute hemolytic anemia, and adverse effects on the liver and kidneys have been reported. It should be handled with care.
Uses of Phenylhydrazine
Phenylhydrazine is mainly used as a synthetic intermediate for dyes, pharmaceuticals, agricultural chemicals, etc., as a reagent for the detection of sugars, aldehydes, and ketones, and for metal precipitation analysis.
In synthetic applications, it is often used as a synthetic intermediate, especially for indoles.
Principle of Phenylhydrazine
Phenylhydrazine is known to turn reddish brown when exposed to air or light. It is also a substance that forms 1/2 hydrates.
It is known to react with oxidants, especially lead dioxide. In storage, it is necessary to avoid mixing with these substances. In addition, carbon monoxide, carbon dioxide, and nitrogen oxides are produced during combustion.
Types of Phenylhydrazine
Phenylhydrazine is sold primarily as a reagent for research and development. It is available as a stand-alone product as well as in hydrochloride salt and other products.
Phenylhydrazine reagent products include 5g, 5g, 100g, 500g, 25mL, 100mL, 500mL and other volumes that are easy to handle in the laboratory. These reagent products can be stored at room temperature. It is available in glass containers, etc.
Phenylhydrazine hydrochloride is also available in 5g , 100g , 500g and other capacities, and is supplied in polyethylene bottles. This is sometimes handled as a reagent that requires refrigerated storage.
Other Information on Phenylhydrazine
1. Synthesis of Phenylhydrazine
The synthesis of phenylhydrazine is a two-step reaction. First, aniline is oxidized with sodium nitrite in the presence of hydrochloric acid. Phenylhydrazine can be produced by reducing the diazonium salt formed by this reaction.
In this case, sodium hydroxide and sodium sulfite are used for the reduction reaction. Tin (II) chloride can also be used as a reducing agent.
2. Chemical Reaction of Phenylhydrazine
Phenylhydrazine reacts with aldehydes and ketones to form phenylhydrazone and with α-ketol to form osazone. Therefore, this substance is sometimes used as a reagent for the detection of these substances.
In terms of synthetic chemistry, it is used as a synthetic raw material for heterocyclic compounds such as pyrazole and pyridazine, and is also a synthetic intermediate for various indoles. Fischer indole synthesis is one of the most famous reactions.
3. Safety and Regulatory Information on Phenylhydrazine
Phenylhydrazine is a toxic substance known to cause contact dermatitis, acute hemolytic anemia, and adverse effects on the liver and kidneys. It is also known to cause carcinogenesis and hereditary diseases.
Since there have been cases of poisoning and other industrial accidents in the past, it is a substance that must be handled safely and in compliance with laws and regulations.