The invention relates to benzimidazole compounds, pharmaceutically acceptable salts thereof and its pharmaceutical compositions for reducing/treating viral infections. The present invention also relates to synthesis of such benzimidazole compounds. The present invention further relates to compositions which comprise such benzimidazole compounds or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier, optionally in combination. The compounds of the invention are useful in reducing/treating viral infections particularly coronavirus infections caused by SARS-CoV, MERS-CoV and SARS-CoV-2.