| abstract |
Compounds are presented of the formula <IMAGE> wherein R1 is selected from the group consisting of hydrogen, amino, halogen and nitro; R2 is selected from the group consisting of hydrogen, lower alkyl, carboxylic acids, esters and primary, secondary or tertiary amides thereof, alkylhydroxy, acylhydroxy-lower alkyl, amino-lower alkyl, alkylamino-lower alkyl, acylamino-lower alkyl and carboxaldehyde; and X is hydrogen or halogen and the pharmaceutically acceptable salts thereof. |