Synthesis of Some 5-Trimethylsilylindoles

5-Trimethylsilylindole has been synthesized starting from indole which was N-benzylated and brominated in the 5 position, metalated to 5-lithio-N-benzylindoline, and treated with trimethylchlorosilane to yield 5-trimethylsilyl-N-benzylindoline. Catalytic hydrogenolysis in the presence of acetic anhydride gave 5-trimethylsilyl-N-acetylindoline, which was hydrolyzed by KOH in diethylene glycol to 5-trimethylsilylindoline, which in turn was converted into 5-trimethylsilylindole by catalytic dehydrogenation in boiling xylene in the presence of palladium-charcoal. 5-Trimethylsilylgramines were synthesized. 5-Trimethylsilylgramine methiodide was converted into the nitrile by reaction with sodium cyanide and the latter was hydrolyzed to 5-trimethylsilylindole-3-acetic acid, or reduced to 5-trimethylsilyltryptamine.