A method for producing 1-[(substituted phenyl)phenylmethyl]piperazines
useful as intermediates for pharmaceuticals and the like, more
particularly, for example, to an intermediate for the production of
antiallergic pharmaceuticals. A 4-(tert-butoxycarbonyl)piperazine compound
of formula (1):
##STR1##
wherein X denotes a chlorine atom, a C1-C3 alkyl group or a C1-C3 alkoxy
group, and an optical isomer present therein.
