3-(8-Aza-bicyclo[3.2.1]oct-2-en-3-yl)-1H-indole → 3-(Indol-3-yl)-8-azabicyclo[3.2.1]octane

Participants

Reaction Steps

The 3-(indol-3-yl)-8-azabicyclo[3.2.1]oct-2-ene may be hydrogenated over a precious metal catalyst, such as palladium on carbon, to give the corresponding 3-(indol-3-yl)-8-azabicyclo[3.2.1]octane. For those compounds of the invention where the indole moiety is substituted with bromo, a hydrogenation catalyst such as sulfided platinum on carbon, platinum oxide, or a mixed catalyst system of sulfided platinum on carbon with platinum oxide is used to prevent hydrogenolysis of the bromo substituent during reduction of the octene double bond. The hydrogenation solvent may consist of a lower alkanol, such as methanol or ethanol, tetrahydrofuran, or a mixed solvent system of tetrahydrofuran and ethyl acetate. The hydrogenation may be performed at an initial hydrogen pressure of 20-80 p.s.i., preferably from 50-60 p.s.i., at 0-60° C., preferably at ambient temperature to 40° C., for 1 hour to 3 days. Additional charges of hydrogen may be required to drive the reaction to completion depending on the specific substrate. The compounds prepared in this manner are isolated by removal of the catalyst by filtration followed by concentration of the reaction solvent under reduced pressure. The product recovered may further purified by chromatography, or by recrystallization from a suitable solvent.

Provenance & Evidence