Synthesis of new derivatives of 2,3-dicyano-imidazo[1,2-a]pyrimidine from 4-hydroxy-6-methylpyran-2-ones

Abstract

The reactions of 2-amino-4,5-dicyanoimidazole 1 with lactone 2 in refluxing alcohol has been carried out for the first time and afforded imidazo[1,2-a]pyrimidines 4 and 5a-d. Condensation of compound 1 with 3-acetyl-4-hydroxy-6-methylpyran-2-one in refluxing n-butanol afforded bis(imidazopyrimidine) derivative 6. Reaction of hydrazine hydrate with ester 5 yielded the corresponding hydrazides 8. Condensation of o-phenylenediamines 9 with compound 5 in refluxing xylene or with hydrazides by melting reagents afforded 2,3-dicyano-5-[benzimidazol-2-yl]methyl-7-methylimidazo[1,2-a] pyrimidines 10a-d.

A new synthetic route for the preparation of 2,2′,5′‐trimethyl‐7‐oxo‐4,7‐dihydro‐[6,7′‐bipyrazolo[1,5‐a]pyrimidine]‐3,3′‐dicarbonitrile, structural elucidation, Hirshfeld surface analysis, energy framework, density functional theory and molecular docking investigations

“…To confirm chemically the structure of compound 3, we based on the results observed during our previous works concerning the condensation of amino-azoles (3-amino-1,2,4-triazole and 2-amino-4,5-dicyano-imidazole) with DHA 2 leading to the biazolopyrimidones, [26] and also in the aim to continue our work on the synthesis of new pyrazolopyrimidine derivatives, we examined the condensation of two moles of compound 1 with one mole of DHA 2. [15][16][17][18][19] We isolated a compound which its spectral data and physical characteristics are similar to those of the compound obtained previously through the condensation of amino-pyrazole 1 with the heterocyclic β-diketone 4 (Scheme 4).…”