Synthesis of 2,3-disubstituted indole on solid phase by the Fischer indole synthesis.

2,3-Disubstituted indoles were synthesized by solid-phase reaction using the Fischer indole synthesis. A "traceless" silicon linker was employed with the silicon-carbon bonding being cleaved with TFA. An oxygen atom was placed into the middle of the spacer/linker so as to enhance solid-phase synthesis by better solvation.

Synthesis of silicon traceless linker for solid-phase reaction.

The silicon linker is the foremost traceless linker used in solid-phase reactions. Hydrogen fluoride (HF) or trifluoroacetic aicd (TFA) can remove the silicon linker with the silicon atom being replaced by a hydrogen atom. In this experiment, the linkers 1c and 2d, which are the most useful in solid-phase reactions, were synthesized.