Synthesis and analgetic activity of nicotinic esters of morphine derivatives

The synthesis of morphine nicotinates is described using nicotinyl chloride in the presence of pyridine. Isomorphine and isocodeine nicotinates were prepared from the corresponding morphine and codeine derivatives with nicotinic acid in the presence of triphenylphosphine and diethyl azodicarboxylate. Unexpectedly the reaction of 14-hydroxy-dihydromorphinone derivatives was anomalous, enolesters were formed. The analgetic activity of selected compounds was determined.