Formation of aryl-bis (6-amino-1,3-dimethyluracil-5-yl) methanes by reaction of 6-amino-1, 3-dimethyluracil with aromatic aldehydes

Recent Advancement in the One-Pot Synthesis of the Tri-Substituted Methanes (TRSMs) and Their Biological Applications

The history of tri-substituted methanes (TRSMs) in chemical industries is much older. Tri-substituted methanes were previously used as dyes in the chemical industries. Still, there is a significant surge in researchers' interest in them due to their wide range of bioactivities. Tri-substituted methane derivatives show a wide range of biological activities like anti-tumor, antimicrobial, antibiofilm, antioxidant, anti-inflammatory, anti-arthritic activities. Due to the wide range of medicinal applications shown by tri-substituted methanes, most of the methodologies reported in the literature for the synthesis of TRSMs are focused on the one-pot method. This review explored the recently reported one-pot processes for synthesizing tri-substituted methanes and their various medicinal applications. Based on the substitution attached to the -CH carbon, this review categorizes them into two major classes: (I) symmetrical and (II) unsymmetrical trisubstituted methanes. In addition, this review gives an insight into the growing opportunities for the construction of trisubstituted scaffolds via one-pot methodologies. To the best of our knowledge, no one has yet reported a review on the one-pot synthesis of TRSMs. Therefore, here we present a brief literature review of the synthesis of both symmetrical and unsymmetrical TRSMs covering various one-pot methodologies along with their medicinal applications.

Hydrogen Bonding in Bis(6-amino-1,3-dimethyluracil-5-yl)-methane Derivatives: Dynamic NMR and DFT Evaluation

Three bis(6-amino-1,3-dimethyluracil-5-yl)-methane derivatives were studied experimentally by variable-temperature (1)H NMR in polar aprotic solutions (CD2Cl2, C5D5N, C2D2Cl4) and computationally by DFT. The unusual for diarylmethanes coplanar conformation of dimethyluracil rings of each molecule is held by a pair of unequal intramolecular N-H···O hydrogen bonds. We show the presence of two dynamic processes involving breakage/formation of these bonds. First, it is two independent NH2 group rotations, each coupled to nitrogen inversion. Second, it is uracil ring rotations (ring flips). The thermodynamic parameters (ΔH(‡), ΔS(‡), and ΔG(‡)) of both processes were estimated by the full line shape analysis of NMR signals and also by DFT calculations. We demonstrate that, though the ring flips exchange pairs of NH protons, the two processes are not coupled: during the ring flip NH2 groups do not rotate, and during the NH2 rotation the rings do not necessarily rotate. Unlike in many other diarylmethanes, the ring flips in the studied compounds are happening stepwise; i.e., the configuration when both rings are "in flight" at the same time is energetically unfavorable (small degree of "cog wheel effect"). The signs of the ΔS(‡) values indicate that the molecular flexibility increases during the NH2 rotations, but decreases during the ring flips.

Synthesis of heterocyclic scaffolds through 6-aminouracil-involved multicomponent reactions

There is a wide range of multicomponent reactions that include 6-aminouracil in the synthesis of heterocyclic compounds. This review highlights the advances in the use of 6-aminouracil in the synthesis of various organic compounds.

Ceric ammonium nitrate (CAN): an efficient and eco-friendly catalyst for the one-pot synthesis of alkyl/aryl/heteroaryl-substituted bis(6-aminouracil-5-yl)methanes at room temperature

Ceric ammonium nitrate (CAN)-catalyzed one-pot synthesis of alkyl/aryl/heteroaryl-substituted bis(6-aminouracil-5-yl)methane scaffolds (3a–3u) has been developed via a pseudo three-component reaction in aqueous ethanol at room temperature.

Reaction of 6-aminouracils with aldehydes in water as both solvent and reactant under FeCl3·6H2O catalysis: towards 5-alkyl/arylidenebarbituric acids

5-Alkyl/arylidenebarbituric acids were efficiently synthesized through an FeCl₃·6H₂O catalyzed domino reaction of 6-aminouracils, water and aldehydes with water serving a dual role as both solvent and reactant, under benign conditions.