Multifloramine synthesis

An improved synthesis of polyhydroxybenzylisoquinolines without protection of the hydroxy-groups has been reported, in which Bischler-Napieralsky ring closure of the appropriate amide is achieved with phosphorus oxychloride in acetonitrile coclaurine, isococlaurine, and reticuline, as well as a key intermediate in the synthesis of multifloramine, have been prepared in this way. 

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