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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 can also be synthesized by the Japp–Klingemann reaction via β-keto acids or β-keto-esters and aryl diazonium salts. Hydrazones are converted to azines when used in the preparation of 3,5-disubstituted 1 H - pyrazoles , [ 11 ] a reaction also well known using hydrazine hydrate .
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 ...
Acetaldehyde is a common electrophile in organic synthesis. [31] In addition reactions acetaldehyde is prochiral. It is used primarily as a source of the "CH 3 C + H(OH)" synthon in aldol reactions and related condensation reactions. [32] Grignard reagents and organolithium compounds react with MeCHO to give hydroxyethyl derivatives. [33]
This reaction is, overall, a condensation reaction as two molecules joining together with loss of water. Mechanistically, it is an example of addition-elimination reaction: nucleophilic addition of the -NH 2 group to the C=O carbonyl group, followed by the elimination of a H 2 O molecule: [3] X-ray structure of DNP-derived hydrazone of ...
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. [19] [20] The reaction was discovered in 1883 by Hermann Emil Fischer. The Fischer indole synthesis. The choice of acid catalyst is very important.
Phenylacetaldehyde is an aldehyde that consists of acetaldehyde bearing a phenyl substituent; the parent member of the phenylacetaldehyde class of compounds. It has a role as a human metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite and a mouse metabolite. It is an alpha-CH2-containing aldehyde and a member of ...
Phenylhydrazine and 2,4-dinitrophenylhydrazine had been used historically in analytical chemistry to detect and identify compounds with carbonyl groups. Phenylhydrazine was used to study the structure of carbohydrates, because the reaction of the sugar's aldehyde groups lead to well crystallizing phenylhydrazones or osazones.