Crystal structure of 3-amino-2-propyl­quinazolin-4(3H)-one

Gamal A El-Hiti; Keith Smith; Amany S Hegazy; Saud A Alanazi; Benson M Kariuki

doi:10.1107/S2056989015013134

. 2015 Jul 22;71(Pt 8):o590–o591. doi: 10.1107/S2056989015013134

Crystal structure of 3-amino-2-propylquinazolin-4(3H)-one

Gamal A El-Hiti ^a,^*, Keith Smith ^b, Amany S Hegazy ^b, Saud A Alanazi ^a, Benson M Kariuki ^b,^*

PMCID: PMC4571413 PMID: 26396813

Abstract

In the title molecule, C₁₁H₁₃N₃O, the propyl group is almost perpendicular to the quinazolin-4(3H)-one mean plane, making a dihedral angle of 88.98 (9)°. In the crystal, molecules related by an inversion centre are paired via π–π overlap, indicated by the short distances of 3.616 (5) and 3.619 (5) Å between the centroids of the aromatic rings of neighbouring molecules. Intermolecular N—H⋯N and N—H⋯O hydrogen bonds form R ₆ ⁶(30) rings and C(5) chains, respectively, generating a three-dimensional network. Weak C—H⋯O interactions are also observed.

Keywords: crystal structure, quinazolin-4(3H)-one, hydrogen bonding, π–π overlap

Related literature

For biological applications of related compounds, see: Sasmal et al. (2012 ▸); Rohini et al. (2010 ▸); Chandregowda et al. (2009 ▸); Gupta et al. (2008 ▸); Alagarsamy et al. (2007 ▸). For the synthesis of substituted quinazolin-4(3H)-ones, see: Ma et al. (2013 ▸); Adib et al. (2012 ▸); Xu et al. (2012 ▸); Kumar et al. (2011 ▸). For modification of the quinazolin-4(3H)-one ring system via lithiation, see: Smith et al. (2004 ▸, 1996 ▸, 1995 ▸). For the crystal structures for related compounds, see: El-Hiti et al. (2014 ▸); Yang et al. (2009 ▸); Coogan et al. (1999 ▸). graphic file with name e-71-0o590-scheme1.jpg

Experimental

Crystal data

C₁₁H₁₃N₃O
M _r = 203.24
Trigonal,
a = 24.1525 (5) Å
c = 9.6500 (2) Å
V = 4875.1 (2) Å³
Z = 18
Cu Kα radiation
μ = 0.67 mm⁻¹
T = 296 K
0.34 × 0.25 × 0.19 mm

Data collection

Agilent SuperNova Dual Source diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2014 ▸) T _min = 0.975, T _max = 0.984
3734 measured reflections
2136 independent reflections
1913 reflections with I > 2σ(I)
R _int = 0.013

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.120
S = 1.06
2136 reflections
146 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2014 ▸); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015 ▸); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▸); software used to prepare material for publication: WinGX (Farrugia, 2012 ▸) and CHEMDRAW Ultra (Cambridge Soft, 2001 ▸).

Supplementary Material

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S2056989015013134/cv5493sup1.cif

e-71-0o590-sup1.cif^{(141.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015013134/cv5493Isup2.hkl

e-71-0o590-Isup2.hkl^{(172.6KB, hkl)}

Click here for additional data file.^{(4.3KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015013134/cv5493Isup3.cml

Click here for additional data file.^{(1.1MB, tif)}

. DOI: 10.1107/S2056989015013134/cv5493fig1.tif

View of (I) showing the atom labels and 50% probability displacement ellipsoids.

Click here for additional data file.^{(1.5MB, tif)}

c . DOI: 10.1107/S2056989015013134/cv5493fig2.tif

Crystal packing viewed along the c axis.

CCDC reference: 1411448

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
N3H3AN2ⁱ	0.91(2)	2.16(2)	3.0677(17)	176.1(16)
N3H3BO1ⁱⁱ	0.87(2)	2.51(2)	3.0599(16)	122.0(15)
C5H5O1ⁱⁱⁱ	0.93	2.44	3.3163(16)	157

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

The authors extend their appreciation to the British Council, Riyadh, Saudi Arabia, for funding this research, and to Cardiff University for continued support.

supplementary crystallographic information

S1. Introduction

Quinazolines have a range of biological activities such as anti-cancer (Chandregowda et al., 2009), anti-bacterial (Rohini et al., 2010), anti-inflammatory (Alagarsamy et al., 2007), anti-obesity (Sasmal et al., 2012) and anti-spasm (Gupta et al., 2008). Synthesis of quinazolin-4(3H)-ones involves use of various synthetic procedures. Recent examples involve reactions of 2-aminobenzonitrile with carbon dioxide in water (Ma et al., 2013), 2-bromobenzamides with formamide catalysed by CuI and 4-hydroxy-l-proline (Xu et al., 2012) and isatoic anhydride, benzyl halides and primary amines under mild Kornblum conditions (Adib et al., 2012). 2-Alkyl-3-aminoquinazolin-4(3H)-ones can be obtained from reactions of 2-alkyl-4H-3,1-benzoxazin-4-ones with hydrazine hydrate (Kumar et al., 2011). Lithiation of 2-unsubstituted and 2-n-alkyl-3-acylaminoquinazolin-4(3H)-ones followed by reactions of the lithium reagents produced in-situ with electrophiles gave the corresponding substituted derivatives in high yields (Smith et al., 2004, 1996, 1995). For the X-ray structures for related compounds, see: El-Hiti et al. (2014); Yang et al. (2009); Coogan et al. (1999).

S2. Experimental

S2.1. Synthesis and crystallization

3-Amino-2-propylquinazolin-4(3H)-one was obtained in 82% yield by reaction of 2-propyl-4H-3,1-benzoxazin-4-one with excess hydrazine hydrate (three mole equivalents) in methanol under reflux conditions for 3 h (Kumar et al., 2011). Crystallization from ethanol gave colourless crystals of the title compound. The NMR and mass spectral data for the title compound were identical with those reported (Kumar et al., 2011).

S2.2. Refinement

The amino hydrogen atoms were located in the difference Fourier map and refined freely. The rest of the H atoms were positioned geometrically and refined using a riding model with U_iso(H) constrained to be 1.2 times U_eq for the atom it is bonded to except for methyl groups where it was 1.5 times with free rotation about the C—C bond.

S3. Results and discussion

In the title compound (I) (Fig. 1), the propyl group is perpendicular to the quinazolin-4(3H)-one group with a dihedral angle of 88.98 (9)° between the least-squares planes of the two groups. In the crystal (Fig. 2), π–π overlap is observed for paired molecules with a centroid-centroid distance of ca 3.62 (1) Å between the benzene and pyrimidine rings of parallel 3-aminoquinazolin-4(3H)-one groups. N—H···N hydrogen bonds form R₆⁶(30) rings and N—H···O form C(5) chains to generate three dimensional packing. Weak C—H···O contacts (C(5)) are also observed.