2-Oxo-2H-chromen-7-yl tert-butyl­acetate

Hypolite Bazié; Eric Ziki; Sorgho Brahima; Veroarisinima Ratsimbazafy; Patrick Roge; Emmanuel Wenger; Abdoulaye Djandé; Claude Lecomte

doi:10.1107/S2414314625001890

. 2025 Mar 4;10(Pt 3):x250189. doi: 10.1107/S2414314625001890

2-Oxo-2H-chromen-7-yl tert-butylacetate

Hypolite Bazié ^a, Eric Ziki ^b,^*, Sorgho Brahima ^a,^*, Veroarisinima Ratsimbazafy ^c, Patrick Roge ^c, Emmanuel Wenger ^d, Abdoulaye Djandé ^a, Claude Lecomte ^d

Editor: W T A Harrison^e

PMCID: PMC11969393 PMID: 40191816

In the title compound, the dihedral angle between the 2H-chromen-2-one ring system and the tert-butylacetate moiety is 72.72 (9)°. In the crystal, the molecules are connected through C—H⋯O hydrogen bonds, generating C(6) chains and R₂²(20) loops that are reinforced by weak aromatic π–π stacking interactions.

Keywords: crystal structure, Hirshfeld surface, coumarin, hydrogen bond

Abstract

In the title compound, C₁₅H₁₆O₄, the dihedral angle between the 2H-chromen-2-one ring system and the tert-butylacetate moiety is 72.72 (9)°. In the crystal, the molecules are connected through C—H⋯O hydrogen bonds, generating C(6) chains and R₂²(20) loops that are reinforced by weak aromatic π–π stacking interactions. The H⋯H, H⋯O/O⋯H, H⋯C/C⋯H and C⋯C contacts contribute 50.6, 29.1, 8.5 and 6.8%, respectively, to the Hirshfeld surface.

Structure description

The title coumarin derivative, C₁₅H₁₆O₄ (I), was synthesized by a research team led by Professor Djandé (LC2M, Ouagadougou, Burkina Faso) as part of the AFRAMED project (Kenfack Tsobnang et al., 2024 ▸). Coumarin-derived compounds exhibit various biological activities, such as anticancer (Yadav et al., 2024 ▸; Rawat et al., 2022 ▸), anticoagulant (Singh et al., 2019), anti-inflammatory (Todeschini et al., 1998 ▸) and anti-glaucoma (Ziki et al., 2023 ▸) properties.

As shown in Fig. 1 ▸, the 2H-chromen-2-one moiety formed by atoms C1–C9/O1/O2 in (I) is almost planar with an r.m.s deviation of 0.027 Å and the dihedral angle between this ring system and the plane formed by atoms C10–C12/C14 in the tert-butylacetate moiety is 72.72 (9)°. An S(6) ring motif resulting from an intramolecular C13—H13B⋯O4 hydrogen bond is observed (Table 1 ▸). The plane passing through atoms C10–C12/C14 of the tert-butylacetate moiety contains the ester function atoms (r.m.s = 0.228 Å), but methyl atoms C13 and C15 atoms are on either side of this plane with deviations of 1.275 (1) and −1.244 (1) Å, respectively.

The molecular structure of (I) with displacement ellipsoids drawn at the 50% probability level.

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C5—H5⋯O4ⁱ	0.95	2.50	3.4144 (13)	161
C11—H11B⋯O2ⁱⁱ	0.99	2.52	3.2523 (13)	131
C13—H13B⋯O4	0.98	2.43	3.0924 (14)	124

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

In the crystal of (I), molecules are linked by weak hydrogen bonds of the C—H⋯O type. A pair of C11—H11B⋯O2(−x + 2, −y, −z + 1) hydrogen bonds generates a centrosymmetric Inline graphic (20) loop, as shown in Fig. 3. The C5—H5⋯O4(x − 1, y, z) hydrogen bonds form C(6) chains propagating in the [100] direction (Fig. 2 ▸). Aromatic π–π stacking interactions between the pyrone ring (centroid Cg1) and benzene ring (centroid Cg2) of a symmetry-related (1 − x, −y, 1 − z) molecule reinforce the cohesion of molecules [Cg1⋯Cg2 = 3.5485 (8) with a slippage of 1.042 Å],

Part of the crystal of (I) showing the formation of an undulating network along the b axis [C(6) and (20) motifs]. Dashed lines indicate hydrogen bonds.

Inline graphic — Part of the crystal of (I) showing the formation of an undulating network along the b axis [C(6) and (20) motifs]. Dashed lines indicate hydrogen bonds.

The Hirshfeld surface and two-dimensional fingerprint (FP) plot of (1) (Fig. 3 ▸) generated by CrystalExplorer21.5 (Spackman et al., 2021 ▸) confirmed the above interactions. The fingerprint plots show the different contributions of the atoms in the crystal-to-surface contacts. The most important contributions are H⋯H and H⋯O/O⋯H contacts with 50.6 and 29.1%, respectively (Fig. 3 ▸d and 3f). The H⋯C/C⋯H and C⋯C contacts contribute 8.5 and 6.8%, respectively. These values are close to those of 2-oxo-2H-chromen-6-yl 4- tert-butylbenzoate (Kenfack Tsobnang et al., 2024 ▸).

(a), (b) Hirshfeld surface of (I) mapped over d_norm, (c) overall two-dimensional fingerprint plot of and those delineated into contributions from different contacts: (d) H⋯H, (d) H⋯C/C⋯H and (e) H⋯O/O⋯H.

Synthesis and crystallization

To a solution of tert-butylacetyl chloride (6.2 mmol, 0.9 ml) in dried diethyl ether (16 ml) was added dried pyridine (4.7 molar equivalents; 2.31 ml) and 7-hydroxycoumarin (6.17 mmol, 1.00 g) in small portions over 30 min. The mixture was left under agitation at room temperature for 3 h and then poured into 40 ml of chloroform. The solution was acidified with dilute hydrochloric acid (5%) until the pH was 2–3. The organic layer was extracted, washed four times with 25 ml of water to neutrality, dried over MgSO₄ and the solvent removed. The resulting crude product was filtered off with suction, washed with petroleum ether and recrystallized from acetone solution as colorless crystals of the title compound. Yield = 79%, m.p. = 368–371 K.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸.

Table 2. Experimental details.

Crystal data
Chemical formula	C₁₅H₁₆O₄
M _r	260.28
Crystal system, space group	Triclinic, P
Temperature (K)	100
a, b, c (Å)	6.1599 (9), 7.2029 (11), 15.202 (2)
α, β, γ (°)	98.765 (5), 99.335 (5), 91.228 (5)
V (Å³)	657.05 (17)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	0.10
Crystal size (mm)	0.20 × 0.12 × 0.07

Data collection
Diffractometer	Bruker D8 Venture
No. of measured, independent and observed [I > 2σ(I)] reflections	53961, 4064, 3720
R _int	0.050
(sin θ/λ)_max (Å⁻¹)	0.719

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.043, 0.137, 1.05
No. of reflections	4064
No. of parameters	172
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.37, −0.28

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Computer programs: APEX4 and SAINT (Bruker, 2019 ▸), SHELXS2018/2 (Sheldrick, 2015a ▸), SHELXL2018/3 (Sheldrick, 2015b ▸), PLATON (Spek, 2020 ▸) and publCIF (Westrip, 2010 ▸).

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2414314625001890/hb4507sup1.cif

x-10-x250189-sup1.cif^{(1.5MB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2414314625001890/hb4507Isup2.hkl

x-10-x250189-Isup2.hkl^{(323.8KB, hkl)}

x-10-x250189-Isup3.cml^{(5KB, cml)}

Supporting information file. DOI: 10.1107/S2414314625001890/hb4507Isup3.cml

CCDC reference: 2427772

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

Acknowledgments

The authors thank the PMD2X X-ray diffraction facility (https://crm2.univ-lorraine.fr/lab/fr/services/pmd2x) of the Université de Lorraine for the X-ray diffraction measurements and the AFRAMED project. CCDC is also thanked for providing access to the Cambridge Structural Database through the FAIRE program. The authors are very grateful to UNESCO, CNRS and the IUCr for their support of the AFRAMED project.

full crystallographic data