Two quinazolinones: a ring conformational study.

The molecules of (+/-)-2-(4-methoxyphenyl)-1-phenethyl-2,3-dihydroquinazolin-4(1H)-one, C(23)H(22)N(2)O(2), (I), and (+/-)-2-(1,3-benzodioxol-5-yl)-1-phenethyl-2,3-dihydroquinazolin-4(1H)-one, C(23)H(20)N(2)O(3), (II), have T-shaped forms in the crystal structure. The tetrahydropyrimidine ring in both structures adopts a sofa conformation. Both molecules are linked by N-H...O and C-H...O hydrogen bonds to form sheets built from alternating R(2)(2)(8) and R(4)(4)(26) [R(4)(4)(24) in (II)] edge-fused rings. Additionally, the structures are stabilized by extensive C-H...pi interactions.

The 1:1 inclusion compounds zolmitriptan-benzene and zolmitriptan-phenol.

In the benzene and phenol solvates of (S)-4-{3-[2-(dimethylamino)ethyl]-1H-indol-5-ylmethyl}oxazolidin-2-one, viz. C(16)H(21)N(3)O(2) x C(6)H(6), (I), and C(16)H(21)N(3)O(2) x C(6)H(5)OH, (II), the host molecule has three linked residues, namely a planar indole ring system, an ethylamine side chain and an oxazolidinone system. It has comparable features to that of sumatriptan, although the side-chain orientations of (I) and (II) differ from those of sumatriptan. Both (I) and (II) have host-guest-type structures. The host molecule in (I) and (II) has an L-shaped form, with the oxazolidinone ring occupying the base and the remainder of the molecule forming the upright section. In (I), each benzene guest molecule is surrounded by four host molecules, and these molecules are linked by a combination of N-H...N, N-H...O and C-H...O hydrogen bonds into chains of edge-fused R(4)(4)(33) rings. In (II), two independent molecules are present in the asymmetric unit, with similar conformations. The heterocyclic components are connected through N-H...N, N-H...O and C-H...O interactions to form chains of edge-fused R(6)(4)(38) rings, from which the phenol guest molecules are pendent, linked by O-H...O hydrogen bonds. The structures are further stabilized by extensive C-H...pi interactions.