Barbituric Acids in Organic Transformations, An Outlook to the Reaction Media

Barbituric acid (pyrimidine-2,4,6(1H,3H,5H)-trione) as odourless white crystals has been prepared in 1864. Due to the acidity of the CH2 group, the pyrimidine ring of barbituric acid could be stabilized via the resonance delocalization, which led it to show potential donor-acceptor properties of the heteroatoms in the molecule. Barbituric acid and its derivatives are versatile moieties in many compounds which possess interesting utility in biology, industry, and drugs. They have been utilized as sedative hypnotics, anticonvulsants, and anaesthetics. Multicomponent reactions play key role in organic and medicinal chemistry. In these types of reactions barbituric acid possess particular position, as a versatile heterocycle, due to its interesting chemical and potent-biological properties. in this report we focused on barbituric acid transformations. The review subdivided with centralization on the solvent presentation. Synthesis of different forms of these scaffolds, by a glance to the reaction media (solventfree conditions, aqueous medium, and organic solvents), have been demonstrated. Solvent-free technique is an environmentally-friendly process in the absence of volatile toxic solvents, which makes it straightly forward to green chemistry. Water as eco-friendly another reaction media with an unusual accelerating effect, which was represented as a systematic phenomenon, could be utilized as a solvent in organic reactions because of its cheapness, safety, and most non toxicity. The review describes the preparation of various heteroaromatic compounds containing barbiturates, which covering the literature relevant up to 2015. Keywords: Barbituric acid, aqueous media, thiobarbituric acid, organic synthesis, reaction media, heteroaromatic compounds.