Processes for the synthesis of levocetirizine and intermediates for use therein

摘要

The present invention provides a compound of formula (IV) wherein R is Cl, Br, NO2, OH or OR′, and R′ is alkyl, and its use in the synthesis of levocetirizine, including its use in the synthesis of (−)-1-[(4-chlorophenyl)-phenylmethyl]piperazine, an intermediate useful in the synthesis of levocetirizine. The present invention also provides compounds (II) and (III) which are useful in the synthesis of compound (IV).