Indigo synthesis

When treated with alkaline hypochlorite solution anthranilic acid is obtained. This reaction, the first stage in the indigo synthesis, is the most important commercial outlet for phthalimide. 

Selenobiotin synthesis, 4, 968 Seleno indigo synthesis, 4, 959 Seleno indigoid dyes applications, 4, 971 Selenolane, octafiuoro-synthesis, 4, 967 Selenolane, tetrafiuoromethyl-synthesis, 4, 967 Selenolo[3,4-b]benzofuran, aryl-synthesis, 4, 1076... 

This simple indigo synthesis of Baeyer should not be omitted if o-nitrobenzaldehyde is available. 

Although the Sandmeyer indigo synthesis is no longer used, it is such an interesting example of the combined efforts of science and in-... 

The reaction product obtained from diphenylcarbodiimide and hydrogen cyanide is an intermediate in Sandmeyers indigo synthesis. HCN can also be eliminated from a-aminocarboxylic acid nitriles 589 to give l-cyano-N,N -disubstituted formamidines 590 and imines 591. ... 

Baeyer-Drewson indigo synthesis. Formation of indigos by an aldol addition of o-nitrobenzal-dehydes to acetone, pymvic acid, or acetaldehyde. Of interest mainly as a method of protecting o-nitro-benzaldehydes. 

Heumann-Pfleger indigo synthesis. Cycli-zation of phenylglycine to indoxyl followed by oxidation by air or oxidizing agents, such as ferric chloride, to yield indigo. 

Propose the mechanism of the Baeyer-Drewson indigo synthesis. 

The so-called second Hemnann indigo synthesis started from anthranilic acid rather than aniline, and gave substantially better yields. Anthranilic acid was accessible by oxidation of naphthalene to phthalic anhydride, after Hoogewerf and van Dorp had shown that Hofmann degradation of the halfamide of phthalic acid leads to the desired product. 

The mechanism of the oxidation with nitrobenzene in basic media is not certain. [144] It is interesting to note the similarity with the second indigo synthesis of Adolf von Baeyer cf. section 2.1.4). 

Ethylene chlorohydrin hydroxyethylating agent, indigo synthesis Ethylene chlorohydrin hydroxyethyiating agent, maionic acid synthesis... 

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