| abstract |
Imidazo[4,5-b]pyridin-2-one derivatives of the formula (I) <IMAGE> (I) in which n is 2, 3 or 4, x is =CH- or =N-, R1 and R2, which may be the same or different, each represent hydrogen, halogen or (C1-4) alkoxy and either R3 is H or OH and R4 is H, or R3 and R4 together form a direct bond, their enantiomers and their addition salts with pharmaceutically acceptable acids are pharmacologically active, for example as antagonists to histamine and serotonin. |