Piperazinophenyl- and piperazinophenyloxycarboxylic acid derivatives, and processes and intermediates for their preparation and pharmaceutical compositions comprising them

A process for preparing a compound corresponding to the formula I:

• ##STR20## wherein Z is oxygen or a methylene group,
• B is a phenyl or pyridyl radical, and
• R.sup.1 is hydrogen or a group forming a biolabile ester, or a physiologically acceptable acid addition salt thereof or a physiologically acceptable salt of an acid of formula I, said process comprising:
• hydrogenating a compound corresponding to formula IIa ##STR21## wherein Z and B have the foregoing meanings and R.sup.201 is an acid protective group, to form a compound corresponding to the formula III ##STR22## wherein Z, B and R.sup.201 have the foregoing meanings, and, provided the acid protective group R.sup.201 in the compound of formula III is not a desired group forming a biolabile ester, removing the acid protective group to liberate the acid of formula I, and
• if R.sup.1 is other than hydrogen, reacting the compound of formula III or acid of formula I obtained therefrom, or a reactive derivative thereof, with an alcohol corresponding to the formula IVa
• R.sup.101 --OH IVa
• wherein R.sup.101 has the meaning indicated for R.sup.1 with the exception of hydrogen, to form a compound corresponding to formula Ia ##STR23## wherein which Z, B and R.sup.101 have the foregoing meanings.