DESIGN, SYNTHESIS AND ANTITUMORAL ACTIVITY OF TRISUBSTITUTED DIHYDROBENZO[A]CARBAZOLES

The design, synthesis, binding affinities for rabbit uterus estrogen r eceptors and in vivo action of two trisubstituted dihydrobenzo[a]carba zoles are reported. Relative binding affinities were similar to tamoxi fen. In vivo studies in rats bearing NMU-induced mammary tumours indic ate that tamoxifen (200 mu g sc daily) led to 51.6% tumour regression, ovariectomy to 54.4%, and derivatives 6 and 7 (200 mu g sc daily) to 50.0 and 54.8%, respectively. These experiments demonstrated that deri vatives 6 and 7 are as effective as tamoxifen in the model studied.