Correlation of psychotomimetic activity of phenethylamines and amphetamines with 1-octanol-water partition coefficients.

In an attempt to relate the hallucinogenic potencies in man of some biologically important amphetamines and phenethylamines, the 1-octanol-water partition coefficients for 11 amphetamines were determined. Using these values and published Hansch pi constants, the log P for 17 additional amines was estimated. It was found that lipophilicity, as measured by the log of the partition coefficient, may be a significant determinant of the level of hallucinogenic potency. The study also suggests that an ideal log P value for psychotomimetric activity in man may be from 2.89 to 3.72.