Novel Synthesis of Arylethynyl Heterocycles

Abstract

A new and simple synthesis of 2-arylethynylindole and 2-arylethynylpyrrole is described. N-Deprotection and subsequent base-catalyzed elimination of N-tosylheteroaryl benzyl ketones are the key steps of the process.

Key words

acetylenes - indole - pyrrole - elimination - tosyl protecting group

References

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9

Reverse phase analytical HPLC was performed on a Waters Alliance 2695 separation module using a Waters Xterra MS C₁₈ column (150 × 4.6 mm, 5 µm) and a Waters 996 PDA detector at 254 nm. The solvent system used was: A: TFA-H₂O, 0.045%, B: TFA-MeCN, 0.036%. A linear gradient from 50% B to 100% B over 15 minutes was used. The retention times of 1 and 3 were 9.1 and 8.4 min, respectively.