| abstract |
Compounds of the formula <IMAGE> wherein R1 is hydrogen, alkyl of 1 to 6 carbon atoms or phenyl(alkyl of 1 to 6 carbon atoms); R2 is hydrogen, alkyl of 1 to 4 carbon atoms or phenyl(alkyl of 1 to 6 carbon atoms); R3 is hydrogen or alkyl of 1 to 6 carbon atoms; n and m are each independently 0, 1 or 2, the sum of n and m being 1 or 2; X, Y and Z are each independently oxygen, sulfur, -NR4-, =CR5-, -CHR5-, <IMAGE> provided that only one of X, Y and Z is O, S <IMAGE> and one or two of X, Y and Z are -NR4-; R4 is hydrogen or alkyl of 1 to 4 carbon atoms; and R5 is hydrogen or, together with a vicinal radical R5, a phenyl ring, or when m and n are both 1, the dihydro form with its double bond in conjugation with the C-terminal carboxylic group; or a non-toxic, pharmacologically acceptable salt thereof. The compounds as well as their salts are useful as antihypertensives. |