Crystal structure of 3-(phenylamino)quinazolin-4(3H)-one, C 14H11N3O

Abstract

(Equation presentation) (Table presentation) Source of material To 3,7 g (16,46mmol) of 2-amino-N'-phenyl hydrazine [7], 22ml of triethyl orthoformate were added. The reaction mixture was refluxed for 5 hours. Thereafter, the mixture is cooled, and the precipitate formed was crystallized from methanol, obtaining 3.26 g (yield 87%). IR (cm-1): 3289 (NH); 3118 (C-H vinylic); 3050, 3036 (CAr-H); 1693 (C=O); 1609 (C=C arom.); 1563 (C=N). 1H-NMR (DMSO-d6, 500 MHz) (ppm) δ: 9.31 (1H, s, H11); 8.44 (1H, s,H3); 8.17 (1H, dd, J = 1.13 and 7.95); 7.90 (1H, td, J = 1.45, 7.88 and 7.42, H7); 7.79 (1H, d, J = 8.06, H6); 7.60 (1H, ddd, J = 0.95, 7.29 and 8.05, H8); 7.21 (2H, t, J = 7.94, H14, H16); 6.86 (1H, t, J = 7.35, H15); 6.69 (2H, d, J = 7.71, H13, H17). 13C-NMR (DMSO-d6, 125.7 MHz (ppm): 159.58 (C4); 150.04 (C2); 147.54 (C10); 147.39 (C12); 134.71 (C8); 129.08 (C14, C16); 127.55 (C9); 127.30 (C7); 126.21 (C6); 122.36 (C5); 120.58 (C15); 112.83 (C13, C17). HRESIMS: m/z 238.0987 for C14H12N3O [M+H]+, calculated: m/z 238,0980. Experimental details H atoms bonded to C atoms were placed geometrically [C-H = 0.95 Å] and allowed to ride during structure refinement, with isotropic displacement parameters fixed at 1.2Ueq(C) of the parent atoms. The other H atoms were located in a difference Fourier map and their coordinates andUiso parameters were refined freely [N-H = 0.88(3)-0.90(3) Å]. Discussion Quinazoline derivatives represent one of the most active classes of compounds possessing a wide spectrum of biological activity [1]. Several reports have been published on the biological activity of quinazoline derivatives, including their bactericidal, herbal and anti-tumor activity [2, 3]. Thus, their synthesis [4, 5] has been of great interest in the elaboration of biologically active heterocyclic compounds. In the title structure there are two crystographically independant molecules in the asymmetric unit. The bond lengths and angles are in the expected ranges. The dihedral angles between the mean plane of quinazoline system [for the non-H atoms, r.m.s. deviations = 0.044 and 0.052 Å] and the phenyl ring are 87.01(10) and 84.59(10)°. In the crystal structure there are two intramolecular and two intermolecular N-H...Nand C-H...Ohydrogen bond interactions respectively. Themolecules interact with neigbouring molecules via intermolecular N-H...N hydrogen bonds forming chains with graph-set notation C(5) [6] along [010]. The structure features two weak π-π interactions with a centroid-centroid distance of 3.8342(16) Å and 3.8987(17) Å. (Cg1-Cg1i: [Cg1:C11-C16]; Cg2-Cg2ii [Cg2: C11A-C16A] (symmetry code: (i) : -x, 2-y, 1-z; (ii):1-x,1-y,1-z). (Table presentation).