Azabicyclooctane-carboxylic acids and pharmaceutical compositions containing them and antihypertensive use thereof

A compound having the formula ##STR17## in which A represents a vinylene or dimethylene radical,

• q is 0 or 1,
• R represents a lower alkyl radical which can carry an amino group,
• X represents --S-- or --NH--,
• R.sub.1 represents a hydrogen atom or a radical of formula ##STR18## R.sub.2 represents a hydroxyl or a lower alkoxy group, R.sub.3 represents a hydrogen atom, a straight or branched alkyl radical, a cycloalkylalkyl radical or a phenylalkyl radical each having no more than a total of 8 carbon atoms, or a radical of formula ##STR19## in which R.sub.4 is H, a lower alkyl radical or a (C.sub.3 to C.sub.6)-cycloalkyl radical,
• R.sub.5 is H, a (C.sub.3 to C.sub.6)-cycloalkyl radical or a (lower alkoxy)carbonyl radical, and
• p is 1 or 2,
• in their racemic form or as optical isomers or the salt thereof obtained with a therapeutically compatible organic or mineral base or the addition salt of the compound of formula (I) in which X is NH with a therapeutically compatible mineral or organic acid.