Compounds possessing Morphine-antagonizing or Powerful Analgesic Properties

Bentley and Hardy 1 and Lister 2 have recently described derivatives of 6,14- endo ethenotetrahydrothebaine and oripavine which are highly potent analgesics in laboratory animals. One of these compounds, 6,14- endo etheno-7-α(2-hydroxypent-2-yl)-tetrahydro-oripavine ( M .183), is a potent analgesic in man 3 . The investigation has been extended to the examination of bases with the general structure I. They were prepared by N -demethylation with cyanogen bromide and hydrolytic removal of the cyano-group, followed by N -alkylation or acylation and reduction with lithium aluminium hydride. A most interesting series of derivatives arises when R 1 is cyclo propylmethyl and forms the subject of this communication.