Isatogens reduction

In the more general area of amino acid chemistry, 14 new unnatural amino acids have been synthesized and explored for biological activity. The crystal structure of L-Trp has been determined and substances such as ninhydrin and isatin have been shown to oxidatively deaminate and decarboxylate a-amino adds to yield aldehydes and isatogen reduction products. The decarboxylation (Strecker d radation) of a-amino adds has been studied with benzil and with benzoin. Both the amino and carboxylic add groups have been induced to... 

Reductive cyclization of 2-nitrobenzil (69a) is reported to give the isatogen 7 la, via the intermediate hydroxylamino compound 69b.38 Little isatogen would be expected under these conditions in view of their... 

In 1906 Angeli and Angelico53 treated 78a with amyl nitrite under alkaline conditions. They isolated the oxime (84), which on treatment with chromic acid gave 79a. They claimed to have identified the isatogen by its reduction to the unstable indoxyl 82 (R = Ph), which has subsequently been shown to give dimeric compounds (Section III,B). 

The reduction of indolones is described together with the reduction of isatogens. The major products of reduction are indoxyls and diindoxyls. In some cases the indoxyls are oxidized by air to benzoxazines (Section III,B). Indolones are comparable with isatogens as oxidizing agents88... 

A detailed study of the polarographic reduction of isatogens and indolones has been published.152 The results further substantiate Scheme 10 and Section III,B. 

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