5-Isopropylimidazolidine-2,4-dione monohydrate

In the title compound, C6H10N2O2·H2O, the imidazole ring is essentially planar, with a maximum deviation of 0.012 (2) Å. In the crystal, molecules are connected via N—H⋯O and O—H⋯O hydrogen bonds, forming a supramolecular tape along the a axis.

In the title compound, C 6 H 10 N 2 O 2 ÁH 2 O, the imidazole ring is essentially planar, with a maximum deviation of 0.012 (2) Å . In the crystal, molecules are connected via N-HÁ Á ÁO and O-HÁ Á ÁO hydrogen bonds, forming a supramolecular tape along the a axis.

Structure Reports Online
The asymmetric unit contains one (S)-5-isopropylimidazolidine-2,4-dione molecule and one water molecule as shown in  (Yu et al., 2004) and 50 other hydantoin derivatives reported in the Cambridge Structural Database (Version 5.28; Allen, 2002) with both unsubstituted NH groups and sp 3 -hybridization at C3. In the crystal structure (Fig. 2), the molecules are connected via N-H···O and O-H···O hydrogen bonds (Table 1), forming a supramolecular tape along the a axis.

Experimental
The DPPOX (1.5 equiv) was added to the equimolar solution of L-valine and urea in MeCN in addition to Et 3 N (1.5 equiv) and the mixture was stirred at 50°C for 60 min. After removal of the solvent, the residue was taken up in organic solvent EtOAc, and washed successively with HCl aq and NaHCO 3 aq. Evaporation of the dried organic solvent gave the title compound. The colourless single-crystals suitable for X-ray analysis was obtained by recrystallization from ethanol (m.p. 145-147 °C; yield: 95%).

Special details
Experimental .  Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )