Jones-Schmid indole synthesis

Indole Ring Synthesis From Natural Products to Drug Discovery, First Edition. Gordon W. Gribble. 2016 John Wiley Sons, Ltd. Published 2016 by John Wiley Sons, Ltd. 

A review of the chemistry of anthranilic acid by Wiklund and Bergman includes some of the chemistry in this chapter [40], 

4-CIPh, 4-BrPh, 4-OMePh, 2-thienyl, 2-naphthyl, 2-(6-MeO)naphthyl 

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An important variation of the Jones-Schmid indole synthesis is the base-mediated cyclization onto esters, which affords 3-hydroxyindoles (indoxyl tautomers) under mild conditions. Three case studies are shown in Scheme 2 (equations 1-3) [18-20]. This chemistry, like that in Table 1 (Entries 4-11), represents a powerful route to C-3 functionalized indoles. Kraus and coworkers use the steri-cally hindered phosphazine base, P -t-Bu, to prepare the 5,6-dihydroindolo[2,l-a]isoquinoline ring system (equation 4) [21]. Several derivatives display immunosuppressive activity. 

Scheme 2 Variations of the Jones-Schmid Indole Synthesis...

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