lesopitron lesopitron lesopitron (e-4424) is a selective full agonist of the 5-ht1a receptor which is structurally related to the azapirones. in 2001 it was under development by esteve as an anxiolytic for the treatment of generalized anxiety disorder (gad). it made it to phase ii clinical trials but was apparently discontinued as no new information on lesopitron has surfaced since. lesopitronclinical dataroutes ofadministrationoralatc codenonelegal statuslegal status in general: uncontrolled identifiers iupac name 2-pyrimidine cas number132449-46-8pubchem cid60813chemspider54801uniih1cgm4755hcomptox dashboard (epa)dtxsid40157587 chemical and physical dataformulac15h21cln6molar mass320.83 g·mol−13d model (jsmol)interactive image smiles clc1cn(nc1)ccccn3ccn(c2ncccn2)cc3