Here's what rhymes with tryptamine.

Consider these alternatives

piperazine / seen piperidine / seen phenothiazine / seen indole / simple benzodiazepine / diazepine phenylethylamine / mean coumarin / falling pyrrolidine / seen triazine / seen papaverine / seen quinoline / line furan / an allopurinol / small hydromorphone / dihydromorphone naphthalene / seen bicyclic / epicyclic alkaloid / avoid pyridine / line glucoside / side sulfone / shown chalcogenide / side