Abstract X(-R1)(-R2)(-R3)-R4 THEIR SALTS AND QUATERNARY AMMONIUM COMPOUNDS, AS WELL AS THEIR OPTICALLY ACTIVE ISOMERS OR DIASTEREOMERS WHEREIN R1 TO R4 REPRESENT HYDROGEN, HALOGEN, LOWER ALKYL, ARALKYL, PHENYL, HYDROXYL, LOWER ALKOXY, NITRO OR LOWER CARBOALKOXY, R5 AND R6 ARE HYDROGEN OR METHYL, R7 AND R8 ARE HYDROGEN, HALOGEN OR LOWER ALKOXY, X IS A HETEROCYCLIC RING SYSTEM, MONO- OR CONDENSED BICYCLIC, WITH 1-4 HETERO ATOMS, IN WHICH THE INDIVIDUAL RINGS HAVE 5 TO 6 MEMBERS AND CAN ALSO CONTAIN 1 OR MORE CARBONYL GROUPS, Y IS -CO- OR -CH(OH)-. THESE COMPOUNDS HAVE PHARMACOLOGICAL ACTIVITY IN THAT THEY INCREASE THE CORONARY BLOOD FLOW BY SIMULTANEOUSLY CAUSING DILATION OF THE CORONARIES AND AN INCREASE IN CONTRACTION STRENGTH. (R7,R8-PHENYL)-CH(-OH)-CH(-R6)-NH-CH2-CH(-R5)-Y- COMPOUNDS OF THE FORMULA