Synthesis of dialkyl 5-(aryl)-1-phenyl-1H-prazole-3,4-dicarboxylates via a one-pot and four-component reaction

A number of new dialkyl 5-(aryl)-1-phenyl-1H-prazole-3,4-dicarboxylate derivatives have been prepared regiospecifically in moderate to good yield from the cyclocondensation reaction of dialkyl (E)-2-(dialkoxyphosphoryl)-3-(aroyl)-2-butenedioate, derived from the reaction between trimethyl phosphite, an acetylenic ester, and an aroyl chloride, with phenylhydrazine. The reaction is four-component and is carried out under reflux conditions in dry toluene.

A facile and direct synthetic entry to dialkyl 5-(aryl)-1-phenyl-1H-prazole-3,4-dicarboxylate via a one-pot, four-component reaction of trimethyl phosphite, acetylenic ester, and aroyl chlorides, and phenylhydrazine under reflux conditions in dry toluene is reported.Figure optionsDownload as PowerPoint slide