RESUMEN
[Formula: see text]-Enaminoesters were generated in situ by the reaction of aliphatic or aromatic primary amines to electron-deficient alkynes, dimethyl acetylenedicarboxylate, and methyl propiolate. [Formula: see text]-Enaminoesters thus formed were reacted with 1-adamantanamine and formaldehyde in methanol to give novel molecular hybrids: dimethyl 3-((3s,5s,7s)-adamantan-1-yl)-1-(alkyl/aralkyl/aryl)-1,2,3,4-tetrahydropyrimidine-5,6-dicarboxylates (5a-j) and methyl 3-((3s,5s,7s)-adamantan-1-yl)-1-(alkyl/aralkyl/aryl)-1,2,3,4-tetrahydropyrimidine-5-carboxylates (9a-j). The structures of the molecular hybrids have been established based on the spectral and analytical data. Structural confirmation of the products was done by X-ray crystallography of 5d as a representative product of the series.
Asunto(s)
Ácidos Carboxílicos/síntesis química , Amantadina/química , Ácidos Carboxílicos/química , Catálisis , Cristalografía por Rayos X , Ciclización , Estructura MolecularRESUMEN
An environmentally benign, simple, efficient, and convenient route is described for the synthesis of novel pyrazolo[1,5-a]pyrimidine derivatives under ultrasound irradiation. Condensation of aminopyrazole 5 with formylated active proton compounds (6, 8, E-G, 12, and 15) furnished pyrazolopyrimidine (7, 9, 10, 13, and 16) in high-to-excellent yields. In comparison with conventional methods, ultrasound irradiation offers several advantages, such as shorter reaction time, higher yields, milder conditions, and environmental friendliness. The reaction is clean with excellent yields and reduces the use of solvents. X-ray crystallographic study of compound 7c confirmed the regioselectivity of the reaction. The antibacterial profile of the newly synthesized compounds was evaluated by cup and saucer method.
Asunto(s)
Antibacterianos/síntesis química , Antibacterianos/farmacología , Pirimidinas/síntesis química , Pirimidinas/farmacología , Sulfatos/química , Ondas Ultrasónicas , Agua/química , Antibacterianos/química , Bacterias/efectos de los fármacos , Técnicas de Química Sintética , Pirimidinas/química , EstereoisomerismoRESUMEN
3-Aminopyrazoles required for the synthesis of pyrazolo[1,5-a]pyrimidines were obtained by the reaction of enaminonitriles with hydrazine hydrate. The resulting aminopyrazoles are reacted with formylated acetophenones under reflux at [Formula: see text] assisted by KHSO[Formula: see text] in aqueous media to form regioselectively 3,7-diarylpyrazolo[1,5-a]pyrimidines and 3,6-diarylpyrazolo[1,5-a]pyrimidine-7-amines. X-ray crystallography of selected compounds 5b and 7i further confirmed the regioselective formation of these products.