Abstract: This invention is directed to 8-phenyl-purines of general formula ##STR1## wherein R.sub.1 is a hydrogen or halogen atom; an alkoxy group optionally substituted by alkylmercapto, alkylsulfinyl or alkylsulfonyl group; or an alkylmercapto, alkylsulfinyl or alkylsulfonyl group, whereby each alkyl moiety may contain from 1 to 3 carbon atoms, andR.sub.2 is an alkoxy group with from 1 to 3 carbon atoms, and their physiologically compatible acid addition salts. The compounds exhibit valuable pharmacological properties, particularly positive inotropic activity.