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Isoniazid has a boxed warning for severe and sometimes fatal hepatitis, which is age-dependent at a rate of 0.3% in people 21 to 35 years old and over 2% in those over age 50. [ 16 ] [ 28 ] Symptoms suggestive of liver toxicity include nausea, vomiting, abdominal pain, dark urine, right upper quadrant pain, and loss of appetite. [ 16 ]
Hydrazine is an inorganic compound with the chemical formula N 2 H 4.It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour.Hydrazine is highly hazardous unless handled in solution as, for example, hydrazine hydrate (N 2 H 4 ·xH 2 O).
Ketazines are also important intermediates in the industrial production of hydrazine hydrate by the peroxide process. [3] In the presence of an oxidant, ammonia and ketones react to give hydrazine via ketazine: 2 Me(Et)C=O + 2 NH 3 + H 2 O 2 → Me(Et)C=NN=C(Et)Me + 2 H 2 O. The ketazine can be hydrolyzed to the hydrazine and regenerate the ketone:
Aerozine 50 is more stable than hydrazine alone, and has a higher density and boiling point than UDMH alone. Pure hydrazine has a higher performance than Aerozine 50, but an inconvenient freezing point of 2 °C. [3] A mix of hydrazine and UDMH has a far lower freezing point due to freezing-point depression.
Acetone hydrazone can be produced on large scale by reaction of acetone azine with hydrazine, a more convenient reaction than direct reaction of acetone and hydrazine. [3] Likewise, it is susceptible to disproportionation to revert to acetone azine and hydrazine, especially in the presence of water.
An applied example is a synthesis of sunitinib begins by mixing 5-fluoroisatin slowly into hydrazine hydrate. [9] After 4 hours at 110 °C, the indole ring structure has been broken into (2-amino-5-fluoro-phenyl)-acetic acid hydrazide with reduction of the ketone at the 3-position.
When derived from hydrazine itself, hydrazones condense with a second equivalent of a carbonyl to give azines: [11] R 2 C=N−NH 2 + R 2 C=O → R 2 C=N−N=CR 2 + H 2 O. Hydrazones are intermediates in the Wolff–Kishner reduction. Hydrazones are reactants in hydrazone iodination, the Shapiro reaction, and the Bamford–Stevens reaction to ...
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