Alkyl hydrazines are known to be much weaker bases than the corresponding aminese2 The N-dimethylaminopiperidine (11) would have the same geometry as (I) but would probably be very little ionized at physiological pH. Thus the effect of change in the strength of the basic group on analgesic potency could be investigated by comparing the activities of compounds of type (I) with those of type (111) which represent weakly basic counterparts ...
