Piperazine-substituted aryl and aralkyl carboxylic acids useful for treating infirmaties caused by excess lipids or thrombocyte

A carboxylic acid compound of the formula:

• ##STR22## wherein A is a valency bond or a saturated branched or straight-chained lower alkylene chain having 1 to 3 carbon atoms,
• B is a valency bond, a saturated lower aliphatic chain having 1 to 3 carbon atoms or an unsaturated lower aliphatic chain having 2 or 3 carbon atoms, and
• R is a hydrogen atom, a straight-chained or branched alkyl group with 1 to 16 carbon atoms, a straight-chained or branched alkyl group with 1 to 3 carbon atoms substituted up to three times by substituents individually selected from the group consisting of hydroxyl, carboxyl, sulphonic acid, 3,5-di-tert-butyl-4-hydroxyphenoxy, phenoxy or phenoxy substituted by a substituent individually selected from the group consisting of C.sub.1 -C.sub.6 lower alkyl, C.sub.1 -C.sub.6 lower alkoxy, halogen, nitro, cyano, carboxyl or acetylamino residue;
• or
• R is a phenylalkyl group, or a 3,5-di-tert-butyl-4-hydroxyphenylalkyl group or a phenylalkyl group the phenyl part being substituted by a substituent individually selected from the group consisting of halogen, hydroxyl, C.sub.1 -C.sub.6 lower alkoxy, cyano, carboxyl, nitro, acetylamino residue, C.sub.1 -C.sub.6 lower alkyl or trifluoromethyl and wherein the alkyl part of which is saturated or unsaturated and has up to 4 carbon atoms;
• or R is a phenacyl group or a phenacyl group the phenyl part of which is substituted by halogen, hydroxyl or C.sub.1 -C.sub.6 lower alkyl;
• or
• R is 2-methyl-3-phenylpropionyl, 3-phenylpropionyl, cinnamoyl, phenacetyl, benzoyl, the phenyl group being the 3,5-di-tert-butyl-4-hydroxyphenyl group or being unsubstituted or substituted by a substituent individually selected from the group consisting of halogen, hydroxyl or C.sub.1 -C.sub.6 lower alkyl, or an acyl group derived from methane-sulphonic acid, benzenesulphonic acid or phenacylsulphonic acid;
• or
• R is a phenyl group or a phenyl group substituted by halogen, trifluoromethyl, phenyl, phenoxy, benzyloxy, 4-chlorobenzyl or 4-chlorophenoxy;
• with the proviso that when A is a valency bond, R cannot be hydrogen, methyl, ethyl, hydroxyethyl, benzyl or phenyl;
• and
• a physiologically acceptable salt, ester or amide thereof formed at the B-COOH carboxyl group, wherein the amides are simple or C.sub.1 -C.sub.6 lower alkyl or hydroxy lower amides and the esters are C.sub.1 -C.sub.6 lower alkyl, C.sub.2 -C.sub.12 di-lower alkyl, amino C.sub.1 -C.sub.6 lower alkyl or benzyl.