A simple substitution to possibly avoid phenol elimination

Several discussions on KP and other sites have focused on the unfeasibility of phenols as drugs because of their tendency to get glucuronidated, become more polar and get rapidly eliminated through the kidneys. So it seems helpful to know what one can do to a phenol in order to retain its electronic properties/steric properties but to prevent glucuronidation and elimination.

Just by chance I came across the following simple substitution: a phenol--->indole change, where the NH of the indole functions like the phenolic OH in hydrogen bonding situations but avoids the unfavourable glucuronidation. Certainly not a general solution, but a useful one that may work in some cases



Reference:
5-, 6-, 7- and 8-amino-2-(N,N-di-n-propylamino)-1,2,3,4-tetrahydronaphthalenes: centrally acting DA and 5-HT1A agonists
European Journal of Medicinal Chemistry, Volume 28, Issue 9, 1993, Pages 693-701
P Stjernlöf, T Elebring, B Andersson, A Svensson, K Svensson, A Ekman, A Carlsson and H Wikström