14-chlorodaunomycin and process for producing 14-chlorodaunomycin and process for producing (2 'R) -4'-O-tetrahydropyramyladriamycin.

摘要

As a new compound is now provided 14-chlorodaunomycin, which is useful as antitumor agent and also as intermediate product for use in the preparation of (2 sec R)-4 min -O-tetrahydropyranyladriamycin in improved yield and in economical way. 14-Chlorodaunomycin is prepared by a process comprising a reaction of daunomycin with an alkyl ortho-formate and a brominating agent to produce a 14-bromo-13-dialkylketaldaunomycin, a hydrolysis of the latter compound by the treatment with an aqueous acid, subsequent halogen-exchange reaction and saponification conducted by a treatment of the resulting aqueous reaction solution containing 14-bromodaunomycin with a metal chloride to produce an acid addition salt of 14-chlorodaunomycin and concurrently salting out the latter compound from the reaction solution, followed by recovering the 14-chlorodaunomycin acid addition salt and optionally treating the latter under weakly alkaline conditions to give 14-chlorodaunomycin in its free base form. (2 sec R)-4 min -O-Tetrahydropyranyladriamycin may be prepared from 14-chlorodaunomycin.