A novel series of N,N-dimethylisotryptamine (isoDMT) derivatives, i.e., derivatives of 1-[2-(dimethylamino)ethyl]indole, was prepared and found to be isosteric with their corresponding N,N-dimethyltryptamine (DMT) counterparts with respect to serotonin receptor (rat fundus) affinity. Whereas the isoDMT derivatives possessed a greater affinity than did their corresponding DMT derivatives, they...