6-Ethoxy-2-phenylindole

Its structural determination had to wait for 25 years until 1998 (98H2481), when we reached the stage where we could apply suitable characteristic reactions found in 1-hydroxyindole chemistry to the synthesis of the authentic 6-ethoxy-2-phenylindole (148). 

A review of the indoledione-indole rearrangement has appeared. The photoirradiation of l-ethoxy-2-phenylindole in methanol has been shown to afford 3- and 6-ethoxy-2-phenylindoles. ... 

MeOH with a Hannovia UV lamp in 1973 (73TL2451). Monitoring with H NMR spectroscopy, only two among many products appeared to contain an ethoxy group. After several separations, 3-ethoxy-2-phenylindole (147, 12%), 2-phenylindole (149, 35%), and an unknown ethoxy-containing 2-phenylindole (unknown 148, 3%) were isolated (Scheme 23). 

Apparently, the isoxazolones (203) can exist in different tautomeric forms and these compounds are photochemically reactive and yield different products from the different tautomeric forms.Some of the reactions encountered are shown in Scheme 4. Sigmatropic migrations are used to explain the formation of the products 3-ethoxy-2-phenylindole and 6-ethoxy-2-phenylin-dole from irradiation of l-ethoxy-2-phenylindole in methanol. The de-ethoxylated compound 2-phenylindole is also formed. The photostability of the novel antibiotic (204) has been assessed. 

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