Process for obtaining Cetirizine dihydrochloride

Process for the synthesis of cetirizine dihydrochloride, wherein (a) a solution of {2-[4-(±-phenyl-p-chlorobenzyl)piperazin-1-yl]}ethanol in 1-7 volumes, referred to the weight of {2-[4-(±-phenyl-p-chlorobenzyl)piperazin-1-yl]}ethanol, of an organic solvent having a boiling point higher than 90°C and being chosen from the group consisting of aliphatic, cycloalifatic or aromatic solvents is provided, whereafter (b) per equivalent of {2-[4-(±-phenyl-p-chlorobenzyl)piperazin-1-yl]}ethanol employed, 1-2 equivalents of a metal haloacetate or of haloacetic acid, as well as 3-7 equivalents of an alkaly metal hydroxyde are added to the solution as per (a), providing a reaction mixture, where 0,05-0,3 volumes, referred to the weight of {2-[4-(±-phenyl-p-chlorobenzyl)piperazin-1-yl]}ethanol employed, of water and 0,1-1,2 volumes, referred to the weight of {2-(4-(±-phenyl-p-chlorobenzyl)piperazin-1-yl]}ethanol employed, of a polar aprotic, water miscible solvent are added, keeping the internal temperature of the reaction mixture below 60°C, whereafter (c) the cetirizine base formed within the reaction mixture is converted into its dihydrochloride salt and isolated as such.