2, 6-Bis (halomethyl) piperidines and their related compounds were synthesized and their antitumor activity was tested with Ehrlich ascites carcinoma, using the in vitro-in vivo test method. These compounds which have a halomethyl group in 2- and 6-positions of the piperidine ring showed a strong antitumor activity in the order of I>Br>Cl in halogen atom of the substituent. 2, 6-Bis (iodomethyl) piperidine hydrochloride (VII) was found to be effective in prolonging the life-span of mice bearing Ehrlich ascites carcinoma when administered intraperitoneally 3 times a day, in a dose of 40 mg/kg.
