oxalylurea ; n,n'-oxalylurea ; nsc 9789 ; parabanic acid ..

Nitrosation of Uric Acid by Peroxynitrite

Synthesis, NMR analysis and applications ..

For the synthesis of parabanic acid and its derivatives, see: Murray (1957, 1963); Ulrichan & Sayigh (1965); Richter (1984); Orazi (1977); Zarzyka-Niemiec & Lubczak (2004). For biological applications of parabanic acid and its derivatives, see: Ishii (1991); Kotani (1997); Sato (2011). For the synthesis, characterization and biological studies of the title compound, see: Xia (2011). For general background to crystallographic studies of compounds having biological activity from our research group, see: Fernandes (2010, 2011); Loughzail (2011). For the synthesis of a precursor mol­ecule, see: Talhi (2011).

From the old literature we emphasize a handful of descriptions reporting the synthesis of parabanic acid (imidazolidine-2,4,5-trione, 1, Fig. 1) and derivatives.

A reinvestigation of parabanic acidЦformaldehyde polymerization

From the old literature we emphasize a handful of descriptions reporting the synthesis of parabanic acid (imidazolidine-2,4,5-trione, 1, Fig. 1) and derivatives. Among the reported synthetic methodologies, this heterocyclic compound can be prepared by the condensation of urea with diethyl oxalate in an ethanolic solution of sodium ethoxide (Murray, 1957; 1963). The synthesis of 1,3-disubstituted parabanic acid derivatives have been reported in a similar fashion, starting from 1,3-dialkylureas and following different pathways. The reaction of oxalyl chloride with 1,3-dialkylureas affords the 1,3-disubstituted parabanic skeleton upon In other cases, the action of oxalyl chloride on has led to 2,2-dichloro-1,3-disubstituted imidazolidine-4,5-diones, which produced the parabanic structure after hydrolysis (Ulrichan & Sayigh, 1965). Furthermore, 3-substituted-5,5-dichlorooxazolidine-2,4-diones were obtained from the reaction of alkyl, aryl, and benzyl with oxalyl chloride, giving in high yields the corresponding imidazolidine-2,4,5-triones after treatment with aniline (Richter , 1984). The selectivity of the direct mono- and di--substitution of parabanic acid has also been discussed in the literature (Orazi , 1977; Zarzyka-Niemiec & Lubczak, 2004). Concerning biological applications, several novel patented forms of parabanic acid derivatives and salts have shown interesting activities such as human AMPK activating, blood glucose-lowering and lipid-lowering activities. In this context, several therapeutic agents containing these compounds as the active principle are, for example, useful drugs in the treatment of diabetic complications (Sato , 2011; Kotani , 1997; Ishii , 1991). In the present study, we describe the of 1,3-dicyclohexylparabanic acid (3) (Fig. 1) (Ulrichan & Sayigh, 1965) which has been isolated a completely different procedure which consists of an oxidative cleavage of the C2'—C5 single bond of 1,3-dicyclohexyl-(3-oxo-2,3-dihydrobenzofuran-2-yl)imidazolidine-2,4-dione (2) (Fig. 1), previously prepared in a two-step reaction involving the action of dicyclohexylcarbodiimide (DCC) on chromone-2-carboxylic acid (Talhi , unpublished data).

BIS(HYDROXYALKYLATED) DERIVATIVES OF PARABANIC ACID …

In the course of our systematic work on the subject we have focused on the synthesis of the low molecular weight products of addition of oxiranes to parabanic acid, i.e.