The reactions of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole as a way to novel azaheterocycles

• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess and
• Viktor I. Saloutin

Beilstein J. Org. Chem. 2015, 11, 385–391, doi:10.3762/bjoc.11.44

• 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

• ; diethyl 2-ethoxymethylidenemalonate; 2-ethoxymethylidene-3-oxo esters; ethyl 2-ethoxymethylidenecyanoacetate; Introduction 2-Ethoxymethylidene-1,3-dicarbonyl compounds are widely recognized as valuable building blocks in designing various open-chain and heterocyclic compounds, including those used in

• esters 1a–d and their analogues (diethyl 2-ethoxymethylidenemalonate (1e), ethyl 2-ethoxymethylidenecyanoacetate (1f)) with 5-AT as a synthetic approach to various azahetrocycles. Results and Discussion It has been found that 2-ethoxymethylidene-3-oxo esters 1a–c react with 5-AT in ethanol under reflux