Yellow or brownish powder
1,3-Dimethyl Barbituric Acid (Urapidil Impurity 4) is a derivative of Barbituric acid. All of the barbituric acid derivatives which have been reported to have pronounced hypnotic activity are disubstituted in the 5-position.
1,3-Dimethylbarbituric acid is used as a catalyst in the Knoevenagel condensation of a series of aromatic aldehydes. It is also used in the synthesis of 5-aryl-6-(alkyl- or aryl-amino)-1,3-dimethylfuro [2,3-d]pyrimidine derivatives and enantioselective synthesis of isochromene pyrimidinedione derivatives.
1,3-Dimethylbarbituric acid (1,3-Dimethyl-2,4,6(1H,3H,5H)-pyrimidinetrione) is an active methylene compound. It undergoes hollow Pd6 water-soluble cage, [{(tmen)Pd}6(timb)4](NO3)12 (tmen= N,N,N′,N′-tetramethylethylenediamine, timb=1,3,5-tris(1-imidazolyl)benzene)-catalyzed Knoevenagel condensation reaction with pyrene-1-carboxaldehyde. It undergoes self-sorted Pd7 molecular boat having an internal nanocavity (catalyst)-assisted Knoevenagel condensation reaction with various aromatic aldehydes. It has been synthesized by reacting 1,3-dimethylurea, malonic acid and acetic anhydride in acetic acid. It is widely used for the synthesis of various synthetic intermediates and heterocyclic compounds.
Crystallise the acid from water and sublime it in a vacuum. Also purify it by dissolving 10g in 100mL of boiling CCl4/CHCl3 (8:2) (1g charcoal), filtering and cooling to 25o. Dry it in vacuo [Kohn et al. Anal Chem 58 3184 1986]. [Beilstein 24 III/IV 1875.]
