The mol-ecule of the title compound, C(17)H(10)N(4)O, has crystallographically imposed C(2) symmetry. The urea group and the benzene ring are nearly coplanar, the dihedral angle between them being 4.15 (7)°. The crystal packing is stabilized by aromatic π-π stacking inter-actions, with a centroid-to-centroid separation of 3.833 (4) Å.

The asymmetric unit of the title compound, C(13)H(10)F(2)N(2)O, contains one and a half N,N'-bis-(4-fluoro-phen-yl)urea mol-ecules. One of the mol-ecules has crystallographic twofold rotation symmetry. The benzene rings are twisted from each other by dihedral angles of 29.69 (6)° for the mol-ecule in a general position and 89.83 (6)° for the symmetry-generated mol-ecule. In the crystal structur...

The carbonyl unit of the title compound, C(13)H(10)Cl(2)N(2)O, lies on a twofold rotation axis. The ring is aligned at 51.6 (1)° with respect to the N-C(=O)-N fragment. The two -NH- fragments of one mol-ecule form hydrogen bonds [2.845 (2) Å] to the C=O fragment of an adjacent mol-ecule, giving rise to the formation of a linear hydrogen-bonded chain.

A number of substituted-α,β-unsaturated carbonyl compounds (1a-i) were prepared by Claisen-Schmidt condensation of substituted acetophenone with selected araldehydes, which on cycloaddition with thiourea furnished 4,6-disubstituted pyrimidine-2-thiols (2a-i). Reaction of (2a-i) with ethyl chloroacetate followed by condensation with hydrazine hydrate yielded 2-[(4,6-disubstituted pyrimidine-2-yl...

H a m i s h G . G r a n t * Department o f Organic Chemistry, University o f Adelaide G . P . O . B o x 498, South Australia 5001 Z. Naturforsch. 34b , 728-733 (1979); received N o v e m b e r 27, 1978 5,6-Disubstituted Indanl -ones , Crotonic Ac id , Po lyphosphor i c Ac id , 1-Methyl Benzofurocyc lopentan-3-one, 1 3C N M R The reaction of several 1,2-disubstituted benzenes with crotonic acid ...