5-(4-Hy­droxy­phen­yl)imidazolidine-2,4-dione

The title compound, C₉H₈N₂O₃, was prepared by reaction of phenol, glyoxylic acid and urea in water. The imidazolidine ring adopts an almost planar conformation (r.m.s. deviation = 0.012 Å) and is twisted by 89.3 (1)° relative to the benzene ring. In the crystal, mol­ecules are linked by N—H...O and O—H...O hydrogen bonds into a three-dimensional framework.

2′,7′-Di­bromo­spiro­[cyclo­propane-1,9′-fluorene]

In the title compound, C₁₅H₁₀Br₂, each mol­ecule is situated on special postion mm, so the asymmetric unit contains one-quater of a mol­ecule. The 2,7-di­bromo-9H-fluorene fragment and three spiro­cyclo­propane C atoms lie on different planes, which are perpendicular to each other. In the crystal, π–π inter­actions between aromatic rings [inter­centroid distance = 3.699 (3) Å] pack the mol­ecules into stacks extending in [001].