Fremgangsmåte for fremstilling av antihistaminiske 4- difenylmetyl/difenylmetoksypiperidinderivater, nye mellomprodukter og anvendelse avdisse

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.