Abstract: This disclosure relates to a class of novel substituted alkylidene imidazole derivatives and pharmaceutically acceptable salts thereof. The disclosure further describes pharmaceutical compositions containing such compounds and to the use of such compounds and compositions as agents for selectively inhibiting the action of the enzyme thromboxane synthetase.

Abstract: Compounds of the general formula: ##STR1## and acid addition salts thereof; in which Ar and Ar.sup.1 which may be the same or different, each represent an aromatic radical which may be substituted one or more times by substituents selected from the following:halogen;lower alkyl;lower alkoxy;alkylenedioxy;aralkoxy;aryloxy;trihalomethyl;carboxy;carboxyalkyl;cyano;carboxamido;di-lower alkylamino;nitro; andlower alkyl sulphonylprovided that one of the groups Ar and Ar.sup.1 carries at least one alkoxy, alkylenedioxy, carboxy or carboxyalkyl substituent; andAlk.sup.1 and Alk.sup.2, which may be the same or different, each represent an alkylene group containing from 1 to 8 carbon atoms which may be substituted one or more times by lower alkyl;X and Y which may be the same or different represent oxygen, nitrogen or sulphur; and in which the imidazole ring may be substituted by one or more lower alkyl substituentshave antithrombotic activity.

Abstract: Compounds of the general formula: ##STR1## and acid addition salts thereof; in whichAr and Ar.sup.1 which may be the same or different, each represent an aromatic radical which may be substituted one or more times by substituents selected from the following:halogen;lower alkyl;lower alkoxy;alkylenedioxy;aralkoxy;aryloxy;trihalomethyl;carboxy;carboxyalkyl;cyano;carboxamido;di-lower alkylamino;nitro; andlower alkyl sulphonylprovided that one of the groups Ar and Ar.sup.1 carries at least one alkoxy, alkylenedioxy, carboxy or carboxyalkyl substituent; andAlk.sup.1 and Alk.sup.2, which may be the same or different, each represent an alkylene group containing from 1 to 8 carbon atoms which may be substituted one or more times by lower alkyl;X and Y which may be the same or different represent oxygen, nitrogen or sulphur; and in which the imidazole ring may be substituted by one or more lower alkyl substituentshave antithrombotic activitiy.