

FURAN RING TRANSFORMATION AS KEY STAGE IN THE SYNTHESIS OF 5H,12H-BENZO[4,5]IMIDAZO[1,2-a]PYRROLO[1,2-d]PYRAZINES

Abstract
We report the first synthesis of new condensed benzimidazole derivatives – 5H,12H-benzo[4,5]imidazo[1,2-a]pyrrolo[1,2-d]pyrazines, based on furan ring transformation in 1-[(5-alkylfuran-2-yl)methyl]- 2-(chloromethyl)benzimidazoles. Two routes are presented for the formation of pyrrolopyrazine system, with different order of steps for the introduction of amino group and opening of the furan ring.
Keywords
furan, pyrazine, pyrrole, pyrrolopyrazines, domino reaction, protolytic ring opening, recyclization.
Latvian Institute of Organic Synthesis - Aizkraukles iela, 21, Riga, LV-1006, Latvia - hgs@osi.lv