Synthesis and pharmacological evaluation of 5-carboxamide-substituted tetrahydrochromeno[7,8-d]imidazoles

Abstract A fast access to novel 5-carboxamide-substituted tetrahydrochromeno[7,8- d ]imidazoles 4 was developed using the readily available preclinical candidate BYK 405879 ( 1 ) as starting material. The 5-amino function was installed by the Curtius rearrangement of carboxylic acid 2 or by the Hofmann rearrangement of carboxamide 8 furnishing benzimidazole 3 as key intermediate. In the Ghosh Schild rat, some of the target compounds 10 – 14 showed noteworthy activity as potassium-competitive acid blockers.