Crystal structure of (Z)-3-{2-[(Z)-11H-indeno[1,2-b]quinoxalin-11-yl­idene]hydrazin­yl}-N-phenyl­but-2-enamide monohydrate

Eldeken, G.A.; El-Samahy, F.A.; Zayed, E.M.; Osman, F.H.; Mahmoud, K.; Elgemeie, G.H.; Jones, P.G.

doi:10.1107/S2056989026002343

research communications

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 82| Part 4| April 2026| Pages 353-356

https://doi.org/10.1107/S2056989026002343

Open

access

Crystal structure of (Z)-3-{2-[(Z)-11H-indeno[1,2-b]quinoxalin-11-ylidene]hydrazinyl}-N-phenylbut-2-enamide monohydrate

Ghada A. Eldeken,^a Fatma A. El-Samahy,^a Ehab M. Zayed,^a Fayez H. Osman,^a Khaled Mahmoud,^b Galal H. Elgemeie ^c and Peter G. Jones ^d ^*

^aDepartment of Green Chemistry, Chemical Industries Research Institute, National Research Centre, 33 El-Buhouth St., Dokki, Giza, PO 12622, Egypt, ^bPharmacognosy Department, National Research Centre, 33 El-Buhouth St., Dokki, Giza, PO 12622, Egypt, ^cChemistry Department, Faculty of Science, Capital University, Helwan, Egypt, and ^dInstitut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany
^*Correspondence e-mail: [email protected]

Edited by C. Schulzke, Universität Greifswald, Germany (Received 12 February 2026; accepted 4 March 2026; online 11 March 2026)

In the title compound, (Z)-3-{2-[(Z)-11H-indeno[1,2-b]quinoxalin-11-ylidene]hydrazinyl}-N-phenylbut-2-enamide monohydrate, C₂₅H₁₉N₅O·H₂O, the configurations around the C=N and C=C double bonds adjacent to the hydrazinyl moiety are both Z. Except for the phenyl group, the molecule is almost planar, promoted by the three-centre intramolecular N_hydrazinyl—H⋯(O_carbonyl, N_quinoxaline) hydrogen bond. The water molecule participates in three hydrogen bonds, as donor towards O_carbonyl (within the asymmetric unit) and the other N_quinoxaline (via an inversion operator) and as acceptor from the amide N—H group (via a b-glide operator). The hydrogen bonds combine to form a layer structure parallel to the ab plane.

Keywords: crystal structure; hydrazinyl; quinoxaline; hydrogen bonds.

CCDC reference: 2535107

1. Chemical context

The pharmaceutical industry has shown great interest in quinoxaline derivatives because they display a wide spectrum of biological properties and can be used against various pathogens and diseases, e.g. bacteria, fungi, viruses, leishmania, tuberculosis, malaria or cancer (Deepika et al., 2011 ; Pereira et al., 2015 ).

Indenoquinoxaline and its derivatives are an important class of nitrogen-containing heterocycles and are useful intermediates in organic synthesis. They have furthermore been found to have applications in various therapies (Tseng et al., 2016 ), as organic semiconductors (Sehlstedt et al., 1998 ; Cheng et al., 2011 ), antiviral agents (Selvam et al., 2013 ), α-glucosidase inhibitors (Khan et al., 2014 ; Hameed et al., 2024 ), anti-inflammatory agents (Schepetkin et al., 2019 ), antimicrobial agents (Kotharkar & Shinde, 2006 ; Sawant et al., 2025 ), acetylcholinesterase (AChE) inhibitors (Akondi et al., 2017 ), antitumor agents (Tseng et al., 2016; Saravana Mani et al., 2018 ) or c-Jun N-terminal kinase (JNK) inhibitors (Schepetkin et al., 2012 ) and as acid corrosion inhibitors for mild steel surfaces (Obot & Obi-Egbedi, 2010 ).

Acetoacetanilide is widely utilized in the synthesis of several heterocyclic compounds. Because of its reactivity and structural flexibility, it is a desirable building block for creating bioactive compounds (Singh et al., 2019 ). The presence of an active methylene group next to a carbonyl and an amide moiety renders it extremely reactive towards primary amines, forming Schiff bases [distinguished by the presence of an imine (—C=N—) functional group] by condensation reactions. These Schiff bases have a wide range of biological functions; they have shown encouraging antimicrobial (Raman et al., 2001 ), anticancer (Subin Kumar, 2021 ) and antifungal (Deepa & Aravindakshan, 2004 ) properties. Imine-containing heterocyclic compounds display a varied chemical reactivity and often show considerable pharmacological effects, which have been attributed to the polarized C=N group (Kovrizhina et al., 2021 ). Notable representatives of these compounds are azines, classified as hydrazine derivatives with the general formula RR′C=N—N=CR′′R′′′.

Continuing our work on the indeno[1,2-b]quinoxaline moiety (Eldeken et al., 2022 ; El-Samahy et al., 2023 ), we are attempting to synthesize new derivatives as potentially active compounds and to study their biological activities as anticancer agents. Treatment (Fig. 1) of 11-hydrazineylidene-11H-indeno[1,2-b]quinoxaline (1) with the acetoacetanilide analogue 3-oxo-N-phenylbutanamide (2) in ethanol in the presence of acetic acid led to the formation of (Z)-3-{2-[(Z)-11H-indeno[1,2-b]quinoxalin-11-ylidene]hydrazinyl}-N-phenylbut-2-enamide monohydrate (4). Compound 4 was formed in good yield via a two-step mechanism involving nucleophilic addition of the primary amine to the carbonyl carbon to give the carbinolamine, followed by dehydration to yield the dienehydrazine 3, containing an (=N—N=) group, followed by tautomerisation to form the mono-ene-hydrazine 4, containing the (—NH—N=) group. The product was recrystallized from acetic acid.

Figure 1
The synthesis of compound 4.

The ¹H NMR spectrum of 4 revealed the presence of two singlets at δ 2.33 and 5.27 ppm corresponding to =C—CH₃ and =CH, respectively. The aromatic protons were observed as a multiplet at δ 7.35–8.06 (13 ArH) ppm and two singlets at δ 9.88, 15.05 ppm, attributed to OH and NH. The ¹³C NMR spectrum of 4 showed signals at δ 18.9 (CH₃) and at 96.1 (=CH), beside the Ar—C signals.

In order to establish the chemical structure of the product 4, its crystal structure was determined and is reported here. The structure was found to be a monohydrate; the water of crystallization probably arose both from the condensation step and also from the acetic acid used for the reaction and the recrystallization, but this was not investigated further. Henceforth, the compound number 4 refers to the monohydrate.

2. Structural commentary

The structure of compound 4 is shown in Fig. 2, with selected molecular dimensions in Table 1. The configurations around the double bonds C11=N1 and C12=C13 are both Z. Except for the phenyl group, the entire molecule is almost planar (Fig. 3), with an r.m.s. deviation of 0.04 Å for non-hydrogen atoms; the atom sequence C15–N3–C14–C13–C12–N2–N1–C11, which connects the two ring systems, is synperiplanar about the bond C12=C13 and antiperiplanar elsewhere. The phenyl group makes an angle of 20.31 (3)° with the main plane. The planarity is associated with the three-centre intramolecular hydrogen bond N2—H02⋯(O1, N10), and the short intramolecular contact H16⋯O1 might also be regarded as a ‘weak' hydrogen bond (Table 2). Other hydrogen bonds are discussed in Supramolecular features. Bond lengths and angles in and around the hydrazide group correspond reasonably well with the formal bond orders (see Database survey); some delocalization of multiple bonding would be expected, and the coordination at N2 is planar [it lies only 0.021 (8) Å out of the plane of its substituents H02, N1 and C12]. The fusing of five- and six-membered rings leads to the usual widening of the corresponding exocyclic bond angles, which are all > 128° and thus appreciably greater than the standard value for sp² carbon atoms. In the five-membered ring, the angle at C11 [106.32 (9)°] is narrow, whereas N1—C11—C10A [131.15 (10)°] is extremely wide and the formal single bonds at C11 are, at ca. 1.47 Å, indeed appreciably longer than the other bonds.

Table 1
Selected geometric parameters (Å, °)

C10A—C11	1.4691 (15)	N2—C12	1.3792 (14)
C11A—C11	1.4678 (15)	N3—C14	1.3602 (15)
N1—C11	1.3004 (14)	C12—C13	1.3570 (15)
N1—N2	1.3458 (13)	C13—C14	1.4597 (15)

C4—C4A—C4B	130.44 (10)	N1—C11—C11A	122.53 (10)
N5—C4B—C4A	128.52 (10)	N1—C11—C10A	131.15 (10)
N10—C10A—C11	128.42 (10)	C11A—C11—C10A	106.32 (9)
C1—C11A—C11	130.32 (10)	C13—C12—N2	121.72 (10)
C11—N1—N2	117.74 (9)	C12—C13—C14	124.36 (10)
N1—N2—C12	118.30 (9)	N3—C14—C13	114.33 (10)
C14—N3—C15	128.53 (10)

C11—N1—N2—C12	−176.41 (10)	C15—N3—C14—C13	176.42 (11)
N1—N2—C12—C13	−179.84 (10)	C12—C13—C14—N3	174.77 (11)
N2—C12—C13—C14	−0.31 (18)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H02⋯N10	0.905 (18)	2.251 (18)	2.9178 (13)	130.2 (14)
N2—H02⋯O1	0.905 (18)	2.008 (17)	2.6860 (13)	130.5 (15)
N3—H03⋯O99ⁱ	0.916 (18)	1.920 (19)	2.8305 (13)	172.7 (17)
O99—H99B⋯N5ⁱⁱ	0.88 (2)	2.04 (2)	2.9032 (14)	168 (2)
O99—H99A⋯O1	0.89 (3)	1.91 (3)	2.7802 (14)	166 (2)
C16—H16⋯O1	0.95	2.32	2.9050 (15)	119
Symmetry codes: (i) $[-x+{\script{3\over 2}}, y-{\script{1\over 2}}, z]$ ; (ii) .

Figure 2
The asymmetric unit of compound 4 in the crystal. Dashed lines indicate hydrogen bonds. Ellipsoids correspond to 50% probability levels.

Figure 3
Side view of compound 4 (water molecule and H atoms omitted).

We have recently published the related hydrazide structure (E)-2-(benzo[d]thiazol-2-yl)-N′-[1-(4-bromophenyl)ethylidene]acetohydrazide (Elboshi et al., 2026 ), which also contains the atom sequence C(sp²)—NH—N=C, but with a C=O rather than a C=C double bond at the first atom. The bond lengths, in this order, are 1.3543 (15), 1.3764 (15) and 1.2942 (15) Å, compared to 1.3792 (14), 1.3458 (13) and 1.3004 (13) Å in 4 (see also Database survey).

3. Supramolecular features

The water molecule participates in three hydrogen bonds, as donor towards O1 (within the asymmetric unit, Fig. 2) and N5 (via inversion), and as acceptor from the amide group N3—H (via a b glide plane). The classical hydrogen bonds (Table 2) combine to form a layer structure parallel to the ab plane (Fig. 4).

Figure 4
Packing of compound 4 showing the formation of a layer structure parallel to the ab plane. The view direction is parallel to the c axis in the region z ≃ 0.5. Thick dashed lines indicate classical hydrogen bonds. Hydrogen atoms not involved in hydrogen bonding are omitted. Atom labels correspond to the asymmetric unit.

4. Database survey

Searches were conducted using CSD Version 6.00 (update August 2025; Groom et al., 2016 ) and the ConQuest routine (Bruno et al., 2002 ), Version 2025.2.0.

A search for the substituted hydrazine moiety (C,C)–C³–N³(H)–N²–C³–(C,C) was conducted, where the superscripts refer to coordination numbers. Disordered structures and those involving metals were excluded; C—C and C—N bond types were restricted to ‘acyclic', but no explicit restrictions were placed on bond orders. This led to 1244 hits. The 1472 values for the N—N bond length gave a mean value of 1.340 (36) Å, corresponding well to the value of 1.3458 (13) Å in 4; similarly, the 1472 values for the N²=C³ bond length gave a mean value of 1.305 (21) Å, cf. 1.3004 (13) Å in 4.

Extending the search fragment to phenyl-NH–C(=O)–C–C³–N³(H)–N²–C³–(C,C), as in 4, gave one hit, namely 2-[2-(2,6-dioxocyclohexylidene)hydrazinyl-N-phenylbenzamide] chloroform solvate (refcode GUCBAL; Bao et al., 2024 ), in which, however, the central C—C³ bond forms part of a phenyl ring.

5. Synthesis and crystallization

A mixture of 11-hydrazineylidene-11H-indeno[1,2-b]quinoxaline 1 (0.01 mol) and 3-oxo-N-phenylbutanamide 2 (0.01 mol) in ethanol (20 ml) and acetic acid (10 ml) was refluxed for 1 h at 353 K. After completion of the reaction (TLC), the solid precipitate thus formed was filtered off and recrystallized from acetic acid. Orange solid; yield 90%; m.p. 501 K; IR (KBr, cm⁻¹): ν 3551, 3055, 1627 (C=N) cm⁻¹; ¹H NMR (500 MHz, DMSO-d₆): δ 2.33 (s, 3 H, =C—CH₃), 5.27 (=H), 7.35–8.06 (m, 13 ArH), 9.88, 15.05 (2s, OH, NH) ppm; ¹³C NMR (125 MHz, DMSO-d₆): δ 18.9 (=C—CH₃), 96.1 (=CH), 119.3, 120.8, 122.6, 123.1, 129.3, 129.7, 129.9, 130.1, 130.9, 132.3, 134.3, 135.4, 141.2, 153.4 and 166.8 ppm; ESI-MS m/z (%) 406 (M⁺ + 1, 100%); Analysis calculated for C₂₅H₁₉N₅O (405.46): C 74.06, H 4.72, N 17.27; found C 74.12, H 4.79, N 17.19%.

6. Refinement

Details of data collection and structure refinement are summarized in Table 3. The hydrogen atoms of the NH groups and the water molecule were refined freely. The methyl group was refined as an idealized rigid group with C—H = 0.98 Å, H—C—H = 109.5°, allowed to rotate but not tip (AFIX 137). Other hydrogen atoms were included using a riding model starting from calculated positions with C(sp²)—H = 0.95 Å. The U_iso(H) values were fixed at 1.5 × U_eq of the parent carbon atoms for the methyl group and 1.2 × U_eq for the other C-bound hydrogen atoms.

Table 3
Experimental details

Crystal data
Chemical formula	C₂₅H₁₉N₅O·H₂O
M_r	423.47
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	100
a, b, c (Å)	23.0033 (6), 7.3011 (2), 24.3621 (6)
V (Å³)	4091.58 (18)
Z	8
Radiation type	Mo Kα
μ (mm⁻¹)	0.09
Crystal size (mm)	0.2 × 0.05 × 0.05

Data collection
Diffractometer	XtaLAB Synergy
Absorption correction	Multi-scan (CrysAlis PRO; Rigaku OD, 2024 )
T_min, T_max	0.766, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	141178, 6816, 5392
R_int	0.050
θ values (°)	θ_max = 31.5, θ_min = 2.4
(sin θ/λ)_max (Å⁻¹)	0.735

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.129, 1.05
No. of reflections	6816
No. of parameters	306
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.45, −0.25
Computer programs: CrysAlis PRO (Rigaku OD, 2024), SHELXT (Sheldrick, 2015a ), SHELXL2019/3 (Sheldrick, 2015b ) and XP (Bruker, 1998 ), publCIF (Westrip, 2010 ).

Supporting information

CCDC reference: 2535107

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S2056989026002343/yz2074sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989026002343/yz2074Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2056989026002343/yz2074Isup3.cml

checkCIF report

Computing details top

(Z)-3-{2-[(Z)-11H-Indeno[1,2-b]quinoxalin-11-ylidene]hydrazinyl}-N-phenylbut-2-enamide monohydrate top

Crystal data top

C₂₅H₁₉N₅O·H₂O	D_x = 1.375 Mg m⁻³
M_r = 423.47	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbca	Cell parameters from 51739 reflections
a = 23.0033 (6) Å	θ = 2.4–34.3°
b = 7.3011 (2) Å	µ = 0.09 mm⁻¹
c = 24.3621 (6) Å	T = 100 K
V = 4091.58 (18) Å³	Prism, orange
Z = 8	0.2 × 0.05 × 0.05 mm
F(000) = 1776

Data collection top

XtaLAB Synergy diffractometer	6816 independent reflections
Radiation source: micro-focus sealed X-ray tube, PhotonJet (Mo) X-ray Source	5392 reflections with I > 2σ(I)
Mirror monochromator	R_int = 0.050
Detector resolution: 10.0000 pixels mm^-1	θ_max = 31.5°, θ_min = 2.4°
ω scans	h = −33→33
Absorption correction: multi-scan (CrysAlisPro; Rigaku OD, 2024)	k = −10→10
T_min = 0.766, T_max = 1.000	l = −35→35
141178 measured reflections

Refinement top

Refinement on F²	Primary atom site location: dual
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.044	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.129	w = 1/[σ²(F_o²) + (0.0614P)² + 2.0644P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max = 0.001
6816 reflections	Δρ_max = 0.45 e Å⁻³
306 parameters	Δρ_min = −0.25 e Å⁻³
0 restraints

Special details top

Refinement. Hydrogen aoms of the NH groups and the water molecule were refined freely.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.55926 (5)	0.53628 (16)	0.67892 (5)	0.0219 (2)
H1	0.597628	0.491157	0.683959	0.026*
C2	0.52021 (6)	0.54307 (18)	0.72255 (5)	0.0258 (2)
H2	0.532377	0.503694	0.757899	0.031*
C3	0.46343 (6)	0.60678 (19)	0.71526 (5)	0.0267 (2)
H3	0.437545	0.608780	0.745636	0.032*
C4	0.44426 (5)	0.66720 (17)	0.66434 (5)	0.0228 (2)
H4	0.405626	0.710036	0.659337	0.027*
C4A	0.48347 (5)	0.66295 (15)	0.62092 (4)	0.0179 (2)
C4B	0.47645 (5)	0.71801 (15)	0.56372 (4)	0.01679 (19)
N5	0.43117 (4)	0.79265 (13)	0.54008 (4)	0.01806 (18)
C5A	0.43816 (5)	0.83076 (15)	0.48502 (4)	0.01676 (19)
C6	0.39134 (5)	0.91033 (16)	0.45643 (5)	0.0203 (2)
H6	0.355943	0.935279	0.475080	0.024*
C7	0.39666 (5)	0.95207 (17)	0.40158 (5)	0.0224 (2)
H7	0.364926	1.005411	0.382419	0.027*
C8	0.44915 (5)	0.91578 (17)	0.37380 (5)	0.0226 (2)
H8	0.452567	0.946315	0.336031	0.027*
C9	0.49542 (5)	0.83703 (16)	0.40042 (5)	0.0204 (2)
H9	0.530381	0.812397	0.381017	0.024*
C9A	0.49099 (5)	0.79269 (15)	0.45668 (4)	0.01694 (19)
N10	0.53842 (4)	0.71632 (13)	0.48283 (4)	0.01743 (18)
C10A	0.53009 (5)	0.68124 (14)	0.53508 (4)	0.01624 (19)
C11A	0.54060 (5)	0.59738 (15)	0.62769 (4)	0.0175 (2)
N1	0.62469 (4)	0.54870 (13)	0.56921 (4)	0.01817 (18)
N2	0.64825 (4)	0.55622 (14)	0.51869 (4)	0.01852 (18)
H02	0.6285 (7)	0.598 (3)	0.4891 (7)	0.032 (4)*
N3	0.74054 (4)	0.56738 (15)	0.36773 (4)	0.02049 (19)
H03	0.7780 (8)	0.533 (3)	0.3750 (7)	0.036 (5)*
O1	0.65281 (4)	0.61976 (13)	0.41018 (4)	0.02395 (18)
C11	0.57135 (5)	0.60445 (15)	0.57494 (4)	0.01708 (19)
C12	0.70363 (5)	0.48796 (15)	0.51146 (5)	0.0181 (2)
C13	0.73033 (5)	0.49112 (16)	0.46180 (5)	0.0194 (2)
H13	0.768566	0.442609	0.459439	0.023*
C14	0.70420 (5)	0.56409 (16)	0.41176 (5)	0.0196 (2)
C15	0.72818 (5)	0.62003 (16)	0.31326 (5)	0.0194 (2)
C16	0.67195 (5)	0.63792 (17)	0.29244 (5)	0.0227 (2)
H16	0.639271	0.619806	0.315658	0.027*
C17	0.66414 (6)	0.68253 (18)	0.23735 (5)	0.0256 (2)
H17	0.625836	0.692895	0.223104	0.031*
C18	0.71115 (6)	0.71209 (18)	0.20294 (5)	0.0264 (2)
H18	0.705214	0.744109	0.165558	0.032*
C19	0.76714 (6)	0.69432 (18)	0.22378 (5)	0.0266 (2)
H19	0.799672	0.714469	0.200533	0.032*
C20	0.77573 (5)	0.64738 (18)	0.27830 (5)	0.0235 (2)
H20	0.814132	0.633652	0.292055	0.028*
C21	0.73298 (5)	0.41143 (16)	0.56135 (5)	0.0203 (2)
H21A	0.737643	0.508452	0.588802	0.031*
H21B	0.771258	0.363308	0.551179	0.031*
H21C	0.709222	0.312495	0.576713	0.031*
O99	0.64052 (4)	0.99027 (14)	0.38653 (4)	0.02674 (19)
H99A	0.6381 (9)	0.871 (3)	0.3938 (9)	0.055 (6)*
H99B	0.6224 (10)	1.052 (3)	0.4124 (9)	0.059 (6)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0225 (5)	0.0222 (5)	0.0211 (5)	−0.0005 (4)	−0.0039 (4)	0.0012 (4)
C2	0.0302 (6)	0.0282 (6)	0.0191 (5)	−0.0011 (5)	−0.0021 (4)	0.0035 (4)
C3	0.0277 (6)	0.0335 (6)	0.0189 (5)	−0.0001 (5)	0.0024 (4)	0.0036 (5)
C4	0.0219 (5)	0.0277 (6)	0.0188 (5)	−0.0007 (4)	0.0024 (4)	0.0018 (4)
C4A	0.0185 (5)	0.0180 (5)	0.0173 (4)	−0.0018 (4)	−0.0002 (4)	0.0003 (4)
C4B	0.0154 (4)	0.0172 (5)	0.0178 (4)	−0.0024 (4)	−0.0002 (4)	−0.0006 (4)
N5	0.0170 (4)	0.0194 (4)	0.0178 (4)	−0.0005 (3)	−0.0001 (3)	−0.0011 (3)
C5A	0.0162 (4)	0.0164 (4)	0.0177 (4)	−0.0017 (4)	−0.0019 (3)	−0.0012 (4)
C6	0.0170 (5)	0.0217 (5)	0.0222 (5)	0.0005 (4)	−0.0028 (4)	−0.0013 (4)
C7	0.0211 (5)	0.0235 (5)	0.0227 (5)	−0.0005 (4)	−0.0065 (4)	0.0000 (4)
C8	0.0240 (5)	0.0252 (6)	0.0185 (5)	−0.0042 (4)	−0.0042 (4)	0.0005 (4)
C9	0.0199 (5)	0.0236 (5)	0.0176 (5)	−0.0036 (4)	−0.0005 (4)	−0.0005 (4)
C9A	0.0153 (4)	0.0175 (5)	0.0180 (4)	−0.0027 (4)	−0.0022 (3)	−0.0012 (4)
N10	0.0156 (4)	0.0189 (4)	0.0178 (4)	−0.0016 (3)	−0.0012 (3)	−0.0015 (3)
C10A	0.0154 (4)	0.0156 (4)	0.0177 (5)	−0.0014 (4)	−0.0014 (3)	−0.0010 (3)
C11A	0.0187 (5)	0.0161 (5)	0.0177 (4)	−0.0015 (4)	−0.0010 (4)	−0.0001 (4)
N1	0.0172 (4)	0.0177 (4)	0.0196 (4)	−0.0006 (3)	−0.0006 (3)	−0.0002 (3)
N2	0.0151 (4)	0.0211 (4)	0.0193 (4)	0.0012 (3)	−0.0009 (3)	0.0003 (3)
N3	0.0152 (4)	0.0263 (5)	0.0199 (4)	0.0024 (4)	−0.0017 (3)	0.0006 (4)
O1	0.0178 (4)	0.0305 (4)	0.0235 (4)	0.0056 (3)	0.0002 (3)	0.0023 (3)
C11	0.0163 (4)	0.0165 (4)	0.0185 (4)	−0.0009 (4)	−0.0018 (3)	−0.0005 (4)
C12	0.0151 (4)	0.0176 (5)	0.0217 (5)	−0.0001 (4)	−0.0022 (4)	0.0001 (4)
C13	0.0155 (4)	0.0210 (5)	0.0218 (5)	0.0021 (4)	−0.0018 (4)	0.0010 (4)
C14	0.0174 (5)	0.0206 (5)	0.0209 (5)	0.0009 (4)	−0.0006 (4)	−0.0006 (4)
C15	0.0195 (5)	0.0196 (5)	0.0192 (5)	0.0008 (4)	−0.0015 (4)	−0.0011 (4)
C16	0.0190 (5)	0.0262 (6)	0.0230 (5)	0.0019 (4)	−0.0013 (4)	0.0006 (4)
C17	0.0243 (6)	0.0274 (6)	0.0251 (6)	0.0029 (5)	−0.0046 (4)	0.0008 (4)
C18	0.0327 (6)	0.0252 (6)	0.0214 (5)	0.0006 (5)	−0.0019 (5)	0.0005 (4)
C19	0.0274 (6)	0.0293 (6)	0.0231 (5)	−0.0014 (5)	0.0038 (4)	−0.0004 (5)
C20	0.0195 (5)	0.0278 (6)	0.0234 (5)	−0.0006 (4)	0.0005 (4)	−0.0008 (4)
C21	0.0168 (5)	0.0212 (5)	0.0230 (5)	0.0012 (4)	−0.0033 (4)	0.0023 (4)
O99	0.0195 (4)	0.0281 (5)	0.0326 (5)	0.0016 (3)	0.0068 (3)	−0.0011 (4)

Geometric parameters (Å, º) top

C1—C2	1.3925 (17)	C13—C14	1.4597 (15)
C1—C11A	1.3932 (15)	C15—C16	1.3953 (16)
C2—C3	1.3978 (18)	C15—C20	1.4007 (16)
C3—C4	1.3885 (16)	C16—C17	1.3927 (17)
C4—C4A	1.3905 (16)	C17—C18	1.3853 (18)
C4A—C11A	1.4084 (15)	C18—C19	1.3905 (19)
C4A—C4B	1.4593 (15)	C19—C20	1.3859 (17)
C4B—N5	1.3091 (14)	C1—H1	0.9500
C4B—C10A	1.4428 (15)	C2—H2	0.9500
N5—C5A	1.3793 (14)	C3—H3	0.9500
C5A—C6	1.4081 (15)	C4—H4	0.9500
C5A—C9A	1.4251 (15)	C6—H6	0.9500
C6—C7	1.3761 (16)	C7—H7	0.9500
C7—C8	1.4093 (17)	C8—H8	0.9500
C8—C9	1.3725 (16)	C9—H9	0.9500
C9—C9A	1.4120 (15)	N2—H02	0.905 (18)
C9A—N10	1.3809 (14)	N3—H03	0.916 (18)
N10—C10A	1.3125 (14)	C13—H13	0.9500
C10A—C11	1.4691 (15)	C16—H16	0.9500
C11A—C11	1.4678 (15)	C17—H17	0.9500
N1—C11	1.3004 (14)	C18—H18	0.9500
N1—N2	1.3458 (13)	C19—H19	0.9500
N2—C12	1.3792 (14)	C20—H20	0.9500
N3—C14	1.3602 (15)	C21—H21A	0.9800
N3—C15	1.4106 (14)	C21—H21B	0.9800
O1—C14	1.2507 (14)	C21—H21C	0.9800
C12—C13	1.3570 (15)	O99—H99A	0.89 (3)
C12—C21	1.4985 (15)	O99—H99B	0.88 (2)

C2—C1—C11A	118.27 (11)	C17—C16—C15	119.46 (11)
C1—C2—C3	121.17 (11)	C18—C17—C16	121.26 (12)
C4—C3—C2	121.07 (11)	C17—C18—C19	119.17 (12)
C3—C4—C4A	117.81 (11)	C20—C19—C18	120.35 (12)
C4—C4A—C11A	121.58 (10)	C19—C20—C15	120.43 (11)
C4—C4A—C4B	130.44 (10)	C2—C1—H1	120.9
C11A—C4A—C4B	107.98 (9)	C11A—C1—H1	120.9
N5—C4B—C10A	123.03 (10)	C1—C2—H2	119.4
N5—C4B—C4A	128.52 (10)	C3—C2—H2	119.4
C10A—C4B—C4A	108.42 (9)	C4—C3—H3	119.5
C4B—N5—C5A	114.77 (9)	C2—C3—H3	119.5
N5—C5A—C6	118.36 (10)	C3—C4—H4	121.1
N5—C5A—C9A	122.09 (10)	C4A—C4—H4	121.1
C6—C5A—C9A	119.54 (10)	C7—C6—H6	119.9
C7—C6—C5A	120.24 (11)	C5A—C6—H6	119.9
C6—C7—C8	120.06 (11)	C6—C7—H7	120.0
C9—C8—C7	121.08 (11)	C8—C7—H7	120.0
C8—C9—C9A	119.91 (11)	C9—C8—H8	119.5
N10—C9A—C9	118.90 (10)	C7—C8—H8	119.5
N10—C9A—C5A	121.93 (10)	C8—C9—H9	120.0
C9—C9A—C5A	119.16 (10)	C9A—C9—H9	120.0
C10A—N10—C9A	114.26 (9)	N1—N2—H02	122.7 (11)
N10—C10A—C4B	123.89 (10)	C12—N2—H02	118.9 (11)
N10—C10A—C11	128.42 (10)	C14—N3—H03	114.9 (11)
C4B—C10A—C11	107.68 (9)	C15—N3—H03	116.6 (12)
C1—C11A—C4A	120.08 (10)	C12—C13—H13	117.8
C1—C11A—C11	130.32 (10)	C14—C13—H13	117.8
C4A—C11A—C11	109.58 (9)	C17—C16—H16	120.3
C11—N1—N2	117.74 (9)	C15—C16—H16	120.3
N1—N2—C12	118.30 (9)	C18—C17—H17	119.4
C14—N3—C15	128.53 (10)	C16—C17—H17	119.4
N1—C11—C11A	122.53 (10)	C17—C18—H18	120.4
N1—C11—C10A	131.15 (10)	C19—C18—H18	120.4
C11A—C11—C10A	106.32 (9)	C20—C19—H19	119.8
C13—C12—N2	121.72 (10)	C18—C19—H19	119.8
C13—C12—C21	121.71 (10)	C19—C20—H20	119.8
N2—C12—C21	116.57 (10)	C15—C20—H20	119.8
C12—C13—C14	124.36 (10)	C12—C21—H21A	109.5
O1—C14—N3	123.42 (11)	C12—C21—H21B	109.5
O1—C14—C13	122.24 (10)	H21A—C21—H21B	109.5
N3—C14—C13	114.33 (10)	C12—C21—H21C	109.5
C16—C15—C20	119.32 (11)	H21A—C21—H21C	109.5
C16—C15—N3	123.66 (10)	H21B—C21—H21C	109.5
C20—C15—N3	116.96 (10)	H99A—O99—H99B	109 (2)

C11A—C1—C2—C3	0.94 (19)	C4—C4A—C11A—C1	−0.60 (17)
C1—C2—C3—C4	−0.7 (2)	C4B—C4A—C11A—C1	179.61 (10)
C2—C3—C4—C4A	−0.3 (2)	C4—C4A—C11A—C11	178.48 (11)
C3—C4—C4A—C11A	0.89 (18)	C4B—C4A—C11A—C11	−1.31 (12)
C3—C4—C4A—C4B	−179.38 (12)	C11—N1—N2—C12	−176.41 (10)
C4—C4A—C4B—N5	3.0 (2)	N2—N1—C11—C11A	178.10 (10)
C11A—C4A—C4B—N5	−177.20 (11)	N2—N1—C11—C10A	−1.40 (18)
C4—C4A—C4B—C10A	−178.52 (12)	C1—C11A—C11—N1	0.22 (19)
C11A—C4A—C4B—C10A	1.24 (12)	C4A—C11A—C11—N1	−178.73 (10)
C10A—C4B—N5—C5A	1.18 (15)	C1—C11A—C11—C10A	179.83 (11)
C4A—C4B—N5—C5A	179.42 (10)	C4A—C11A—C11—C10A	0.87 (12)
C4B—N5—C5A—C6	179.66 (10)	N10—C10A—C11—N1	−1.8 (2)
C4B—N5—C5A—C9A	−0.54 (15)	C4B—C10A—C11—N1	179.47 (11)
N5—C5A—C6—C7	179.41 (11)	N10—C10A—C11—C11A	178.67 (11)
C9A—C5A—C6—C7	−0.39 (17)	C4B—C10A—C11—C11A	−0.09 (12)
C5A—C6—C7—C8	−0.19 (18)	N1—N2—C12—C13	−179.84 (10)
C6—C7—C8—C9	0.69 (18)	N1—N2—C12—C21	−0.30 (15)
C7—C8—C9—C9A	−0.59 (18)	N2—C12—C13—C14	−0.31 (18)
C8—C9—C9A—N10	−178.95 (10)	C21—C12—C13—C14	−179.83 (11)
C8—C9—C9A—C5A	0.00 (17)	C15—N3—C14—O1	−4.1 (2)
N5—C5A—C9A—N10	−0.39 (16)	C15—N3—C14—C13	176.42 (11)
C6—C5A—C9A—N10	179.41 (10)	C12—C13—C14—O1	−4.71 (19)
N5—C5A—C9A—C9	−179.31 (10)	C12—C13—C14—N3	174.77 (11)
C6—C5A—C9A—C9	0.49 (16)	C14—N3—C15—C16	−15.78 (19)
C9—C9A—N10—C10A	179.56 (10)	C14—N3—C15—C20	167.07 (12)
C5A—C9A—N10—C10A	0.64 (15)	C20—C15—C16—C17	0.02 (18)
C9A—N10—C10A—C4B	−0.02 (15)	N3—C15—C16—C17	−177.07 (11)
C9A—N10—C10A—C11	−178.59 (10)	C15—C16—C17—C18	−0.9 (2)
N5—C4B—C10A—N10	−0.97 (17)	C16—C17—C18—C19	0.9 (2)
C4A—C4B—C10A—N10	−179.52 (10)	C17—C18—C19—C20	0.1 (2)
N5—C4B—C10A—C11	177.85 (10)	C18—C19—C20—C15	−1.0 (2)
C4A—C4B—C10A—C11	−0.69 (12)	C16—C15—C20—C19	0.93 (19)
C2—C1—C11A—C4A	−0.33 (17)	N3—C15—C20—C19	178.21 (12)
C2—C1—C11A—C11	−179.19 (11)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H02···N10	0.905 (18)	2.251 (18)	2.9178 (13)	130.2 (14)
N2—H02···O1	0.905 (18)	2.008 (17)	2.6860 (13)	130.5 (15)
N3—H03···O99ⁱ	0.916 (18)	1.920 (19)	2.8305 (13)	172.7 (17)
O99—H99B···N5ⁱⁱ	0.88 (2)	2.04 (2)	2.9032 (14)	168 (2)
O99—H99A···O1	0.89 (3)	1.91 (3)	2.7802 (14)	166 (2)
C16—H16···O1	0.95	2.32	2.9050 (15)	119

Symmetry codes: (i) −x+3/2, y−1/2, z; (ii) −x+1, −y+2, −z+1.

Acknowledgements

The authors acknowledge support by the Open Access Publication Funds of the Technical University of Braunschweig.

References

Akondi, A. M., Mekala, S., Kantam, M. L., Trivedi, R., Raju Chowhan, L. & Das, A. (2017). New J. Chem. 41, 873–878. Web of Science CSD CrossRef Google Scholar
Bao, M.-Z., Pan, X.-Y., Wu, W.-R., Xiao, L., Liu, J., Liu, X., Zhang, S.-S. & Zhao, L. (2024). Chem. Commun. 60, 12928–12931. Web of Science CrossRef CAS Google Scholar
Bruker (1998). XP. Bruker Analytical X–Ray Instruments, Madison, Wisconsin, USA. Google Scholar
Bruno, I. J., Cole, J. C., Edgington, P. R., Kessler, M., Macrae, C. F., McCabe, P., Pearson, J. & Taylor, R. (2002). Acta Cryst. B58, 389–397. Web of Science CrossRef CAS IUCr Journals Google Scholar
Cheng, C., Jiang, B., Tu, S.-J. & Li, G. (2011). Green Chem. 13, 2107–2115. Web of Science CrossRef CAS Google Scholar
Deepa, K. P. & Aravindakshan, K. K. (2004). Appl. Biochem. Biotechnol. 118, 283–292. Web of Science CrossRef PubMed CAS Google Scholar
Deepika, Y., Surendra, P., Sachin, N. K. & Shewta, S. (2011). Int. J. Curr. Pharm. Rev. Res. 2, 33–46. Google Scholar
Elboshi, H. A., Azzam, R. A., Elgemeie, G. H. & Jones, P. G. (2026). Acta Cryst. E82, 293–296. Web of Science CrossRef IUCr Journals Google Scholar
Eldeken, G. A., El-Samahy, F. A., Zayed, E. M., Osman, F. H. & Elgemeie, G. E. H. (2022). J. Mol. Struct. 1261, 132929. Web of Science CrossRef Google Scholar
El-Samahy, F. A., Eldeken, G. A., Zayed, E. M., Osman, F. H. & Elgemeie, G. E. H. (2023). ChemistrySelect 8, e202300639. Google Scholar
Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. Web of Science CrossRef IUCr Journals Google Scholar
Hameed, S., Saleem, F., Özil, M., Baltaş, N., Salar, U., Ashraf, S., Ul-Haq, Z., Taha, M. & Khan, K. M. (2024). Int. J. Biol. Macromol. 263, 129517. Web of Science CrossRef PubMed Google Scholar
Khan, M. S., Munawar, M. A., Ashraf, M., Alam, U., Ata, A., Asiri, A. M., Kousar, S. & Khan, M. A. (2014). Bioorg. Med. Chem. 22, 1195–1200. Web of Science CrossRef PubMed Google Scholar
Kotharkar, S. A. & Shinde, D. B. (2006). Bioorg. Med. Chem. Lett. 16, 6181–6184. Web of Science CrossRef PubMed CAS Google Scholar
Kovrizhina, A. R., Samorodova, E. I. & Khlebnikov, A. I. (2021). Molbank M1299. Google Scholar
Obot, I. B. & Obi-Egbedi, N. O. (2010). Mater. Chem. Phys. 122, 325–328. Web of Science CrossRef Google Scholar
Pereira, J. A., Pessoa, A. M., Cordeiro, M. N. D., Fernandes, R., Prudêncio, C., Noronha, J. P. & Vieira, M. (2015). Eur. J. Med. Chem. 97, 664–672. Web of Science CrossRef CAS PubMed Google Scholar
Raman, N., Kulandaisamy, A., Shunmugasundaram, A. & Jeyasubramanian, K. (2001). Transition Met. Chem. 26, 131–135. Web of Science CrossRef CAS Google Scholar
Rigaku OD. (2024). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, England. Google Scholar
Saravana Mani, K., Murugesapandian, B., Kaminsky, W. & Rajendran, S. P. (2018). Tetrahedron Lett. 59, 2921–2929. Web of Science CSD CrossRef Google Scholar
Sawant, S., Patil, P., Salunke, G., Kamble, R., Bharmal, M., Sankpal, S., Sonawane, K. & Hangirgekar, S. (2025). J. Mol. Struct. 1321, 140069. Web of Science CrossRef Google Scholar
Schepetkin, I. A., Khlebnikov, A. I., Potapov, A. S., Kovrizhina, A. R., Matveevskaya, V. V., Belyanin, M. L., Atochin, D. N., Zanoza, S. O., Gaidarzhy, N. M., Lyakhov, S. A., Kirpotina, L. N. & Quinn, M. T. (2019). Eur. J. Med. Chem. 161, 179–191. Web of Science CrossRef PubMed Google Scholar
Schepetkin, I. A., Kirpotina, L. N., Khlebnikov, A. I., Hanks, T. S., Kochetkova, I., Pascual, D. W., Jutila, M. A. & Quinn, M. T. (2012). Mol. Pharmacol. 81, 832–845. Web of Science CrossRef PubMed Google Scholar
Sehlstedt, U., Aich, P., Bergman, J., Vallberg, H., Nordén, B. & Gräslund, A. (1998). J. Mol. Biol. 278, 31–56. Web of Science CrossRef CAS PubMed Google Scholar
Selvam, P., De Clercq, E. & Pannecouque, C. (2013). Int. J. Drug Des. Dis 4, 1017–1019. CAS Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Singh, R. K., Kumar, A. & Mishra, A. K. (2019). Lett. Org. Chem. 16, 6–15. CrossRef CAS Google Scholar
Subin Kumar, K. (2021). J. Coord. Chem. 74, 2798–2816. Web of Science CrossRef CAS Google Scholar
Tseng, C. H., Chen, Y. R., Tzeng, C. C., Liu, W., Chou, C. K., Chiu, C. C. & Chen, Y. L. (2016). Eur. J. Med. Chem. 108, 258–273. Web of Science CrossRef PubMed Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.