Eight N-methyl-N-isopropyltryptamines (MIPTs) possessing various aromatic oxygen substituents were prepared, characterized, and evaluated for hallucinogenic activity in man. In at least two instances (the Ar H and the Ar 5-OCH3, 1 and 4) the unsymmetrical nitrogen substitution led to a substantial increase in potency as well as oral activity when compared to the symmetrical dimethyl homologues. Qualitatively, 4-hydroxy-N-methyl-N-isopropyltryptamine (2) was the most interesting in overall effect, producing a classic hallucinogenic profile. The 5-methoxy congener 4 resulted in a state characterized by heightened conceptual stimulation lacking in visual phenomena. Other members of the series exhibited diminished effects.
