Search results
Results from the WOW.Com Content Network
Phenylhydrazine was the first hydrazine derivative characterized, reported by Hermann Emil Fischer in 1875. [7] [8] He prepared it by reduction of a phenyl diazonium salt using sulfite salts. Fischer used phenylhydrazine to characterize sugars via formation of hydrazones known as osazones with the sugar aldehyde. He also demonstrated in this ...
Hydrazines (R 2 N−NR 2) are a class of chemical compounds with two nitrogen atoms linked via a covalent bond and which carry from one up to four alkyl or aryl substituents. . Hydrazines can be considered as derivatives of the inorganic hydrazine (H 2 N−NH 2), in which one or more hydrogen atoms have been replaced by hydrocarbon grou
Borsche–Drechsel cyclization is the central step in Borsche–Drechsel carbazole synthesis, where in the first step phenylhydrazine is condensed with cyclohexanone to form the cyclohexanone phenylhydrazone, and in the final step the resulting tetrahydrocarbazole is oxidized to carbazole itself.
The Fischer indole synthesis is a chemical reaction that produces the aromatic heterocycle indole from a (substituted) phenylhydrazine and an aldehyde or ketone under acidic conditions. [1] [2] The reaction was discovered in 1883 by Emil Fischer. Today antimigraine drugs of the triptan class are often synthesized by this method. The Fischer ...
Hydrazones are converted to azines when used in the preparation of 3,5-disubstituted 1H-pyrazoles, [11] a reaction also well known using hydrazine hydrate. [ 12 ] [ 13 ] With a transition metal catalyst , hydrazones can serve as organometallic reagent surrogates to react with various electrophiles.
Osazone formation was developed by Emil Fischer, [3] who used the reaction as a test to identify monosaccharides.. The formation of a pair of hydrazone functionalities involves both oxidation and condensation reactions. [4]
Some troops leave the battlefield injured. Others return from war with mental wounds. Yet many of the 2 million Iraq and Afghanistan veterans suffer from a condition the Defense Department refuses to acknowledge: Moral injury.
DNPH is a reagent in instructional laboratories on qualitative organic analysis. Brady's reagent or Borche's reagent, is prepared by dissolving DNPH in a solution containing methanol and some concentrated sulfuric acid.