Fremgangsmater for fremstilling av verdifulle terapeutisk aktive piperidinderivater

The present invention is related to novel intermediates and processes which are useful in the preparation of certain antihistaminic piperidine derivatives of formula (I) wherein W represents -C(=O)- or -CH(OH)-; R 1 represents hydrogen or hydroxy; R 2 represents hydrogen; R 1 and R 2 taken together form a second bond between the carbon atoms bearing R 1 and R 2 ; n is an integer of from 1 to 5; m is an integer 0 or 1; R 3 is -COOH or -COOalkyl wherein the alkyl moiety has from 1 to 6 carbon atoms and is straight or branched; each of A is hydrogen or hydroxy; and pharmaceutically acceptable salts and individual optical isomers thereof, with the proviso that where R 1 and R 2 are taken together to form a second bond between the carbon atoms bearing R 1 and R 2 or where R 1 represented hydroxy, m is an integer 0.