Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Nitration of indole-3-carboxylic esters, and , afforded 4-nitro derivatives, and . was regioselectively derived to , which contains substituents at 4- and 7-positions of indole nucleus similarly to teleocidins. ... , was regioselectively derived to , which contains substituents at 4- and 7- ...