Abstract
The asymmetric unit of the compound, C20H26N2O5 center dot 0.5-0.5C(2)H(5)OH, consists of two tetrahydropyrimidine-2,4-dione molecules and an ethanol molecule. The pyrimidine rings are nearly planar (r.m.s. deviation = 0.006 angstrom in one molecule and 0.009 angstrom in the other); the C atom at the 5-position deviates by 0.083 (3) angstrom [0.064 (3) angstrom in the second molecule] from the mean plane and the C atom at the 6-position by 0.034 (3) angstrom [0.082 (3) angstrom in the second molecule]. In each molecule, the benzene ring is nearly perpendicular to the pyrimidine ring, the dihedral angle is 88.51 (8)degrees in one molecule and 84.70 (8)degrees in the other. The amino group of each tetrahydropyrimidine-2,4-dione molecule is a hydrogen-bond donor to the exocyclic O atom at the 2-position of an adjacent molecule, the hydrogen bond generating an inversion dimer in each case. The ethanol molecule forms a hydrogen bond to the methoxy O atom of one of two independent molecules.