| abstract |
Compounds of general formula (I), wherein R1 and R2 are independently selected from the group consisting of hydrogen, chloro, bromo, nitro, cyano, trifluoromethyl, and R3 and R4 are independently selected from straight or branched lower (1-5 carbon atoms) alkyl groups, and including all optical isomers, provided that when R3 is methyl and R4 is tert.-butyl, then R1/R2 are not hydrogen/hydrogen, hydrogen/2'-trifluormethyl, 2'-chloro/3'-chloro, and when R3 is methyl and R1/R2 is hydrogen/3'-nitro, then R4 are not methyl, ethyl, propyl, iso-propyl, tert.-butyl, processes for their preparation, pharmaceutical preparations containing them and the use of the compounds in lowering the blood pressure. |