Reactions of 6‐Aminouracils: The First Simple, Fast, and Highly Efficient Synthesis of bis(6‐Aminopyrimidonyl)methanes (BAPMs) Using Thermal or Microwave‐Assisted Solvent‐Free Methods

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.

Synthesis of aminouracil-tethered tri-substituted methanes in water by iodine-catalyzed multicomponent reactions

An efficient, mild and environmentally benign protocol has been developed for the synthesis of aminouracil-tethered tri-substituted methane derivatives. The three-component reaction of 2-hydroxy-1,4-naphthaquinone, 6-amino-1,3-dimethyluracil and aldehydes in the presence of molecular iodine as catalyst under reflux conditions resulted in aminouracil-tethered tri-substituted methane derivatives 4 in aqueous medium. Similarly, the four-component reaction of 2-hydroxy-1,4-naphthaquinone, o-phenylenediamine, aldehydes and aminouracil derivatives resulted in aminouracil-tethered tri-substituted methane derivatives 6 under the same reaction conditions. The notable features of this protocol are simple experimental procedure, cheap catalyst, readily available starting materials, moderate-to-good yields of the products having biologically active important moieties such as aminouracil, hydroxy-naphthaquinone/benzophenazine.

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.

Synthesis of 5,5′-(arylmethylene)bis(pyrimidinone) derivatives in aqueous media

The condensation and addition reactions of aromatic aldehydes and 4,6-dihydroxypyrimidine or 2,4-dihydroxy-6-aminopyrimidine in water in the presence of triethylbenzylammonium chloride (TEBAC) afford a one-pot synthesis of 5,5′-(arylmethylene)bis[6-hydroxypyrimidine-4(3H)-one]s and 5,5′-(arylmethylene)bis[6-aminopyrimidine-2,4 (1H,3H)-dione]s. These compounds were characterised by elemental analysis and IR and 1H NMR spectra and further confirmed by a single crystal X-ray diffraction analysis.

Reactions of 6-aminouracils — A novel and highly efficient procedure for preparation of some new spiro pyridodipyrimidines under classical or microwave-assisted solvent-free conditions

A versatile and highly efficient procedure has been introduced for preparation of spiro pyridodipyrimidines during the investigation of the reaction of 1,3-dimethyl-6- aminouracil with isatin derivatives, ninhydrin, and acenaphthoquinone under classical or microwave-assisted solvent-free conditions.Key words: isatin, ninhydrin, acenaphtoquinone, 1,3-dimethyl-6-aminouracil, solvent-free.