DDD-016 is a novel pentacyclic compound initially designed and synthesized as a potential atypical antipsychotic, with its receptor binding affinities screened across a broad panel of over 80 central nervous system and other receptors. As part of a series of investigational compoundsâÂÂwhich also includes DDD-024, DDD-025, and DDD-029 stands out for its proposed anti-psychotic activity, believed to be mediated through dual serotonin 5-HT<sub>2A</sub> and dopamine D2 receptor antagonism.
A Goldberg reaction between 2-aminothiophenol [137-07-5] (1) and 2-bromobenzyl bromide [3433-80-5] (2) gives 5,11-Dihydrodibenzo[b,e][1,4]thiazepine, [3048-78-0] (3). Nitrosylation with nitrous acid gives (4). This is then reduced to the amino group. Condensation with 1-Methyl-4-piperidone [1445-73-4] gives (5). Fischer indole synthesis completes the synthesis.
{Note that the Goldberg reaction is being replaced by the Hartwig amination.}
Rajagopalan also invented a highly novel antidepressant earlier in his career: