Non-catalytic multicomponent rapid and efficient approach to 10-(2,4,6-trioxohexahydropyrimidin-5-yl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-ones from salicylaldehydes, dimedone, and barbituric acids

Asymmetric synthesis of 9-alkyl tetrahydroxanthenones via tandem asymmetric Michael/cyclization promoted by chiral phosphoric acid

A tandem asymmetric Michael-addition/cyclization of cyclic 1,3-dicarbonyl compounds to β,γ-unsaturated α-ketoesters catalyzed by chiral phosphoric acid is presented. This protocol provides a facile approach for the construction of enantioenriched 9-alkyl tetrahydroxanthenones, an ubiquitous framework found in a number of natural products and pharmaceutical molecules, in high yields with good to high enantioselectivities.

A fast and efficient ‘on-solvent’ cascade assembling of salicylaldehydes and dimethylbarbituric acid into 5-(1,3-dimethyl-2,4-dioxo-1,3,4,5-tetrahydro-2H-chromeno[2,3-d]pyrimidin-5-yl)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-triones

A fast (15 min) and efficient cascade reaction of salicylaldehydes and 1,3-dimethylbarbituric acid in the presence ofp-TsOH as a catalyst furnishes substituted 5-(1,3-dimethyl-2,4-dioxo-1,3,4,5-tetrahydro-2H-chromeno[2,3-d]pyrimidin-5-yl)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-triones1a–h, containing both chromeno[2,3-d]pyrimidine and hexahydropyrimidine-2,4,6-trione pharmacologically active fragments, in 95–99% yields. This new procedure is characterized by the use of inexpensive reagents and a simple workup.

Synthesis of Pyrazole-Thiobarbituric Acid Derivatives: Antimicrobial Activity and Docking Studies

A one-pot reaction was described that results in various pyrazole-thiobarbituric acid derivatives as new pharmacophore agents. These new heterocycles were synthesized in high yields with a broad substrate scope under mild reaction conditions in water mediated by NHEt₂. The molecular structures of the synthesized compounds were assigned based on different spectroscopic techniques. The new compounds were evaluated for their antibacterial and antifungal activity. Compounds 4h and 4l were the most active compounds against C. albicans with MIC = 4 µg/L. Compound 4c exhibited the best activity against S. aureus and E. faecalis with MIC = 16 µg/L. However, compounds 4l and 4o were the most active against B. subtilis with MIC = 16 µg/L. Molecular docking studies for the final compounds and standard drugs were performed using the OpenEye program.

Recent applications of barbituric acid in multicomponent reactions

This review aims to show representative examples of multicomponent reactions utilizing barbituric acid in the synthesis of various heterocyclic structures.