NOVEL INTERMEDIATES FOR THE PREPARATION OF ANTIHISTAMINIC 4-DIPHENYLMETHYL/DIPHENYLMETHOXY PIPERIDINE DERIVATIVES

The present invention is related to novel intermediates and processes which are useful in the preparation of certain antihistaminic piperidine derivatives of formula (I): (See formula I) wherein W represents -C(=O)- or -CH(OH)-; R1 represents hydrogen or hydroxy; R2 represents hydrogen; R1 and R2 taken together form a second bond between the carbon atoms bearing R1 and R2; n is an integer of from 1 to 5; m is an integer 0 or 1; R3 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 R1 and R2 are taken together to form a second bond between the carbon atoms bearing R1 and R2 or where R1 represented hydroxy, m is an integer 0.