title: The reactions of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole as a way to novel azaheterocycles.
abstract: The interaction of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole is an efficient synthetic approach to novel azaheterocycles. 2-Ethoxymethylidene-3-oxo esters bearing alkyl substituents react with 5-aminotetrazole to form ethyl 2-azido-4-alkylpyrimidine-5-carboxylates which are capable of subsequent nucleophilic substitution. The use of diethyl 2-ethoxymethylidenemalonate in this reaction resulted in ethyl 7-hydroxytetrazolo[1,5-a]pyrimidine-6-carboxylate, while ethyl 2-ethoxymethylidenecyanoacetate yielded 5-[2,6-diamino-3,5-bis(ethoxycarbonyl)pyridinium-1-yl]tetrazol-1-ide through an alternative pathway. Ethyl 2-benzoyl-3-ethoxyprop-2-enoate reacted with 5-aminotetrazole by two reaction routes to form ethyl 2-benzoyl-3-(1H-tetrazol-5-ylamino)prop-2-enoate and ethyl 7-(1-ethoxy-1,3-dioxo-3-phenylpropan-2-yl)-5-phenyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate.
authors.affiliation: Postovsky Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, 22 S. Kovalevskoy St., 620137 Ekaterinburg, Russia.
authors.forename: Marina V
authors.initials: MV
authors.lastname: Goryaeva
authors.affiliation: Postovsky Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, 22 S. Kovalevskoy St., 620137 Ekaterinburg, Russia.
authors.forename: Yanina V
authors.initials: YV
authors.lastname: Burgart
authors.affiliation: Postovsky Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, 22 S. Kovalevskoy St., 620137 Ekaterinburg, Russia.
authors.forename: Marina A
authors.initials: MA
authors.lastname: Ezhikova
authors.affiliation: Postovsky Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, 22 S. Kovalevskoy St., 620137 Ekaterinburg, Russia.
authors.forename: Mikhail I
authors.initials: MI
authors.lastname: Kodess
authors.affiliation: Postovsky Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, 22 S. Kovalevskoy St., 620137 Ekaterinburg, Russia.
authors.forename: Viktor I
authors.initials: VI
authors.lastname: Saloutin
keywords: 2-ethoxymethylidene-3-oxo esters; 5-aminotetrazole; cyclisation; diethyl 2-ethoxymethylidenemalonate; ethyl 2-ethoxymethylidenecyanoacetate