ChemInform Abstract: 6‐Nitro‐ and 6‐Bromo Derivatives of 7‐Oxo‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidine.

Abstract

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A Short Synthesis of the Triazolopyrimidine Antibiotic Essramycin

“…Although not isolated as natural products previously, 1,2,4triazolo [1,5-a]pyrimidines are nevertheless quite well-known compounds, being previously investigated, for example, as vasodilators and herbicides. 7 In planning a synthesis of essramycin (1) we considered routes based on the known triazolopyrimidine acetic acid derivative 2 8 or on the amino-1,2,4-triazole 3 9 (Scheme 1). In the event, we elected to use the latter precursor, and therefore our synthesis started with the condensation of aminoguanidine bicarbonate with ethyl benzoylacetate in nbutanol to give the amino-1,2,4-triazole 3 in 32% yield.…”

Synthesis of Essramycin and Comparison of Its Antibacterial Activity

“…The synthesis of 1 (Scheme ) proceeded via a 3-amino-1,2,4-triazole intermediate 3 , which was isolated as a minor product from the reaction between aminoguanidine and ethyl benzoylacetate . Compound 3 and ethyl acetoacetate were then heated under acidic conditions followed by recrystallization from methanol to yield compound 1 with 98% purity. The spectroscopic data of compound 1 were consistent with those previously reported .…”