Intermediates useful for the preparation of antihistaminic piperidine derivatives

The present invention is related to novel intermediates which are useful in the preparation of certain piperidine derivatives which are useful as antihistamines, antiallergy agents and bronchodilators [U.S. Pat. No. 4,254,129, Mar. 3, 1981, U.S. Pat. No. 4,254,130, Mar. 3, 1981, U.S. Pat. No. 4,285,958, Apr. 25, 1981 and U.S. Pat. No. 4,550,116, Oct. 29, 1985]. The present invention is related to a novel intermediates and processes which are useful in the preparation of certain antihistaminic piperidine derivatives of the formula whereinW represents -C( O)- or -CH(OH)-;Rrepresents hydrogen or hydroxy;Rrepresents hydrogen;Rand Rtaken together form a second bond between the carbon atoms bearing Rand R;n is an integer of from 1 to 5;m is an integer 0 or 1;Ris -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; andpharmaceutically acceptable salts and individual optical isomers thereof,with the proviso that where Rand Rare taken together to form a second bond between the carbon atoms bearing Rand Ror where Rrepresented hydroxy m is an integer 0.