Emil Fischer indole synthesis

First law of thermodynamics, 24 645-648 First limiting amino acid, 2 601 First-order irreversible chemical kinetics, 25 286-287, 292-293 First-principle approach, in particle size measurement, 13 153 First sale doctrine, 7 793 Fischer, Emil, 16 768 Fischer carbene reaction, 24 35-36 Fischer esterification, 10 499 Fischer formula, 4 697 Fischer-Indole synthesis, 9 288 Fischer lock and key hypothesis, 24 38 Fischer-Tropsch (FT) synthesis, 6 791, 827 12 431... 

There is no need to restrict our discussion to carbon and oxygen atoms. We shall finish this section with two useful reactions that use other elements. The most famous synthesis of indoles is a nineteenth century reaction discovered by Emil Fischer—the Fischer indole synthesis—and it would be a remarkable discovery even today. Reaction of phenylhydrazine with a ketone in slightly acidic solution gives an imine (Chapter 14) called a phenylhydrazone. 

You are about to see one of the great inventions of organic chemistry. It is a remarkable reaction, amazing in its mechanism, and it was discovered in 1883 by one of the greatest organic chemists of all, Emil Fischer. Fischer had earlier discovered phenylhydrazine (PhNHNH2) and, in its simplest form, the Fischer indole synthesis occurs when phenylhydrazine is heated in acidic solution with an aldehyde or ketone. 

Fischer indole synthesis. Emil Fischer discovered that pyruvic acid phenyl-liydiazone on being heated with zinc chloride loses ammonia with cyclization to... 

The Fischer indole synthesis has become the most popular method to prepare indole rings since its discovery in 1883 by Emil Fischer.In essence, the Fischer indole synthesis can be regarded as the cyclization of an arylhydrazone, prepared from an arylhydrazine, an aldehyde, or a ketone, by treatment with an acid catalyst or effected thermally to form the indole nucleus. The mechanism has been the subject of intensive investigations for over a century, and many intermediates have been isolated and characterized. By consensus from both theoretical and experimental evidence, the Fischer indole synthesis proceeds as shown below" ... 

The classic and most convenient synthesis of the indole moiety is that of Emil Fischer. Recent examples of its use for drug synthesis includes one preparation of the nonsteroidal antiinflammatory agent, indoxole (2). Reaction of ketone 1 with phenylhydrazine in acetic acid leads directly to indoxole (2). Alternately, anisoin (3) can be reacted... 

Emil Fischer (1852-1919), discovered phenylhydrazine as a PhD student in 1875, succeeded Hofmann at Berlin in 1900 where he built the then largest chemical institute in the world, and was awarded the Nobel prize in 1902. As well as his work on indoles, he laid the foundations of carbohydrate chemistry by completing the structure and synthesis of the main sugars. If only he hadn t also invented Fischer projections ... 

A logical beginning in the presentation of indole ring synthesis is with Emil Fischer and his indole synthesis, which has been in vogue since his discovery in 1883 [1] and subsequent exploration [2-5]. 

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