I'm personaly learning about SPECT as I want to use this technique, so that's the reason why I came across this great article. But the synthetic aspect is also interesting. I hope that you will find it as interesting as I did. Enjoy!

Abstract: The synthesis and spectral properties of new radioiodinated indolealkylamines like 2-[¹³¹I]-iodo-N,N-dimethyltryptamine, 2-[¹³¹I]-iodo-N-methyltryptamine, 2-[¹³¹I]-iodo-5-methoxy-N,N-dimethyltryptamine, 2-[¹³¹I]-iodio-5-hydroxy-N,N-dimethyltryptamine (2-[¹³¹I]-iodo-bufotenine), and 2-[¹³¹I]-iodo-tryptamine and the known 2-[¹³¹I]-iodo-N-acetly-5-methoxy-tryptamine (2-[¹³¹I]-iodo-melatonine) are described herein. There were synthesized by a high-yield novel method, and their spectral properties are fully described. These compounds are of biological importance and can be used for brain mapping with SPECT technology.

Journal of Labelled Compounds and Radiopharmaceuticals Vol. XXXIX No. 8

Fulltext:

http://pharmacist-hive.tripod.com/indolealkylamines.pdf