Redetermination at 113 K of 2,2-tetra-methylene-1,2-dihydroquinazolin-4(3H) -one

The title compound {systematic name: spiro-[cyclo-pentane-1, 2′(1′H)-quinazolin]-4′(3′H)-one]}, C12H14N2O, has been reported previously [Klemm, Weakley, Gilbertson & Song (1998). J. Heterocycl Chem. 35, 1269-1273]. Its structure has been redetermined at 113 K with greater precision for all data. The mol-ecule is built up from two fused six-membered rings and one five-membered ring linked through a spiro C atom. The pyrimidine ring has an envelope conformation and the cyclopentane ring adopts a distorted boat form. There are inter-molecular N - H⋯O hydrogen bonds, which form a two-dimensional sheet parallel to the (001) plane.