E'ii'ry-i\ I (1 S', S4-dihiibstituted piperaziiie derivatives, iii which The SI siilJhtitiieiita are 9,-i,. i- tiii: ietlios2. belizoyl or::, 4,. i-triniethosyt) eii~(~~-lnl~ yl aid the?;'siibstitiieiith are methyl, 2-(2'- hydrosyethoxy) ei hyl, cyclohesyl, Ireiizyl, in-met hj-1-or pt-hritylt) etizyl, 2-phenethyl, pheiiyl, chloio-01' rnethoxypheiiyl, tolyl, 2,, B-sylylJ Thr a,> h (i\ vii by gross observatioii of int, act animal. couditioiied-avoidaiice behavior., 2-pyi, iniidyl, or 2-thiazolyl grorip:', have been of ...