Processes and intermediates in the preparation of morphine analogs via N-demethylation of N-oxides using cyclodehydration reagents

摘要

A high-yielding method for the N-demethylation of oxycodone- and oxymorphone-N-oxides by the reaction of these compounds with cyclodehydration reagents has been performed. This method has been utilized to improve the synthesis of various morphine analogs, such as naltrexone, nalbuphone and naloxone.