A series of eight C5-substituted analogues of (*)-lO, ll-dihydro-5Hdibenzo [a, d] cyclohepten- 5, lO-imine (1) have been prepared by the directed lithiation-alkylation (and acylation) of its (*)-N-tert-butylformamidinyl derivative 2 followed by formamidine solvolysis. An additional 10 analogues were prepared by elaboration of the C5-ethyl ester derivative. Analogues possessing large (eg propyl and larger) lipophilic substituents displace [3H]-1-(1- ...