Abstract Alkylation of 1-ethoxycarbonylpiperazine with 4-fluorobenzyl bromide, 2-(4- fluorophenyl) ethyl bromide and 4, 4-bis (4-fluorophenyl) butyl bromide gave the carbamates IIa, IIb and IIf. Two further similar compounds (IIc, IId) were obtained by reactions of 1-(2- chloroethyl)-4-ethoxycarbonylpiperazine with 4-fluorophenol, and with 4-fluorothiophenol, respectively. Hydrolysis of carbamates IIa-f resulted in piperazine derivatives IIIa-f ...