Redetermination at 113 K of 2,2-tetra-methyl-ene-1,2-dihydro-quinazolin-4(3H)-one.

The title compound {systematic name: spiro-[cyclo-pentane-1,2'(1'H)-quinazolin]-4'(3'H)-one]}, C(12)H(14)N(2)O, 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.