Being bifunctional, with two amines, hydrazine is a key building block for the preparation of many heterocyclic compounds via condensation with a range of difunctional electrophiles. With 2,4-pentanedione, it condenses to give the 3,5-dimethylpyrazole. In the Einhorn-Brunner reaction hydrazines react with imides to give triazoles. Hydrazine is a convenient reductant because the by-products are typically nitrogen gas and water. Thus, it is used as an antioxidant, an oxygen scavenger, and a corrosion inhibitor in water boilers and heating systems. It is also used to reduce metal salts and oxides to the pure metals in electroless nickel plating and plutonium extraction from nuclear reactor waste. Hydrazine is an inorganic chemical compound with the formula N2H4. It is a colourless liquid with an ammonia-like odor and is derived from the same industrial chemistry processes that manufacture ammonia. However, hydrazine has physical properties that are more similar to those of water. The propanone azine is an intermediate in the Atofina-PCUK synthesis. Direct alkylation of hydrazines with alkyl halides in the presence of base affords alkyl-substituted hydrazines, but the reaction is typically inefficient due to poor control on level of substitution (same as in ordinary amines). The reduction of hydrazones to hydrazines present a clean way to produce 1,1-dialkylated hydrazines.
belongs to the class of inorganic compounds known as homogeneous other non-metal compounds. These are inorganic non-metallic compounds in which the largest atom belongs to the class of 'other non-metals'.
At least two mechanisms of action have been observed. One involves the direct binding of those hydrazines with a free amino group (hydrazine and 1,1-dimethylhydrazine) to key cellular molecules. Hydrazine reacts with alpha-keto acids such as vitamin B6 to form hydrazoines compounds. By binding to keto acids and forming hydrazones, hydrazine inhibits oxygen consumption with mitochondrial substrates in vitro. A second mechanism involves the generation of reactive species such as free radical intermediates or methyldiazonium ions as a result of metabolism. (6)
Metabolism
Hydrazines are likely to be more rapidly absorbed into the blood after ingestion or exposure to the skin than after inhalation. Once in the blood, they are probably carried to all the tissues of the body. Soon after exposure, the levels of hydrazines in the tissues fall since they are metabolised in several products such as acetyl-, diacetylhydrazine, pyruvate hydrazone, urea, and acyclic compound (1,4,5,6-tetrahydro-6-oxo-3-pyridazine carboxylic acid). However, these metabolites interacts with some important proteins and might be harmful to the body. Some studies showed that metabolites and unchanged hydrazine leave the body within one day.
Small amounts can also be found in the expired air. (6, 1)
Hydrazine is mainly used as a foaming agent in preparing polymer foams, but significant applications also include its uses as a precursor to polymerization catalysts and pharmaceuticals. Additionally, hydrazine is used in various rocket fuels and to prepare the gas precursors used in air bags. Exposure may occur from breathing contaminated air in or near a facility that makes, processes, or uses hydrazines, eating fish contaminated with hydrazines, drinking or swimming in water that has been contaminated with hydrazines, or touching soil contaminated with hydrazines, such as near some military bases or hazardous waste sites. Breathing cigarette smoke indirectly or using tobacco products may expose to small amounts of hydrazine or 1,1-dimethylhydrazine. (6)
Breathing hydrazines for short periods may cause coughing and irritation of the throat and lungs, convulsions, tremors, or seizures. Breathing hydrazines for long periods may cause liver and kidney damage, as well as serious effects on reproductive organs. Eating or drinking small amounts of hydrazines may cause nausea, vomiting, uncontrolled shaking, inflammation of the nerves, drowsiness, or coma. (6)
Symptoms
Hydrazine may cause corrosive burning sensations, confusion, convulsions, abdominal cramps, headache, unconsciousness, vomiting, weakness, shortness of breath, or sore throat and cough, depending on the route of exposure. (5)
Treatment
Induced emesis, gastric lavage, use of saline cathartics, or activated charcoal are commonly used to decrease the gastrointestinal absorption of hydrazines. In general, these treatments are most effective when used within a few hours after oral exposure. Following dermal or ocular exposures to hydrazines, all contaminated clothing should be removed, and contacted skin should be washed immediately with soap and water. Eyes that have come in contact with hydrazines should be flushed with copious amounts of water. Contact lenses should be removed prior to flushing with water. (6)
