Crystal structure of 10-benzyl-9-(3,4-di­meth­oxy­phen­yl)-3,3,6,6-tetra­methyl-3,4,6,7,9,10-hexa­hydro­acridine-1,8(2H,5H)-dione

N Sureshbabu; V Sughanya

doi:10.1107/S2056989015014966

. 2015 Aug 26;71(Pt 9):o688–o689. doi: 10.1107/S2056989015014966

Crystal structure of 10-benzyl-9-(3,4-dimethoxyphenyl)-3,3,6,6-tetramethyl-3,4,6,7,9,10-hexahydroacridine-1,8(2H,5H)-dione

N Sureshbabu ^a, V Sughanya ^a,^*

PMCID: PMC4555413 PMID: 26396906

Abstract

In the acridinedione moiety of the title compound, C₃₂H₃₇NO₄, the central dihydropyridine ring adopts a flattened-boat conformation, with the N atom and the methine C atom displaced from the mean plane of the other four atoms by 0.0513 (14) and 0.1828 (18) Å, respectively. The two cyclohexenone rings adopt envelope conformations, with the tetrasubsituted C atoms as the flap atoms. The 3,4-dimethoxybenzene and benzyl rings are almost normal to the dihydropyridine mean plane, with dihedral angles of 89.47 (9) and 82.90 (11)°, respectively. In the crystal, molecules are linked via a pair of C—H⋯O hydrogen bonds, forming inversion dimers, which are, in turn, linked by C—H⋯O hydrogen bonds, forming slabs lying parallel to (001).

Keywords: crystal structure, dimedone, benzylamine, acridinedione

Related literature

For therapeutic properties of acridine derivatives, see: Nasim & Brychcy (1979 ▸); Thull & Testa (1994 ▸). For the crystal structures of similar decahydroacridine-1,8-diones, see: Sughanya & Sureshbabu (2012 ▸); Abdelhamid et al. (2011 ▸); Akkurt et al. (2014 ▸); Khalilov et al. (2011 ▸); Tang et al. (2008 ▸); Tu et al. (2004 ▸). For a related synthesis, see: Li et al. (2003 ▸); Sughanya & Sureshbabu (2012 ▸). For ring conformation analysis, see: Cremer & Pople (1975 ▸).

Experimental

Crystal data

C₃₂H₃₇NO₄
M _r = 499.63
Orthorhombic,
a = 10.7068 (3) Å
b = 17.8750 (4) Å
c = 28.1694 (7) Å
V = 5391.2 (2) Å³
Z = 8
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 296 K
0.35 × 0.35 × 0.30 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▸) T _min = 0.958, T _max = 0.989
23489 measured reflections
4661 independent reflections
2966 reflections with I > 2σ(I)
R _int = 0.045

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.119
S = 1.01
4661 reflections
335 parameters
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.14 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▸); cell refinement: APEX2 and SAINT (Bruker, 2004 ▸); data reduction: SAINT and XPREP (Bruker, 2004 ▸); program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▸); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▸); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▸) and Mercury (Macrae et al., 2008 ▸); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008 ▸).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989015014966/su5190sup1.cif

e-71-0o688-sup1.cif^{(35.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015014966/su5190Isup2.hkl

e-71-0o688-Isup2.hkl^{(228.4KB, hkl)}

Click here for additional data file.^{(10.8KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015014966/su5190Isup3.cml

Click here for additional data file.^{(2.1MB, tif)}

. DOI: 10.1107/S2056989015014966/su5190fig1.tif

A view of the molecular structure of the title compound, with atom labelling. Displacement ellipsoids are drawn at the 30% probability level.

Click here for additional data file.^{(2MB, tif)}

b . DOI: 10.1107/S2056989015014966/su5190fig2.tif

A view along the b axis of the crystal packing of the title compound. The C—H⋯O hydrogen bonds are shown as dashed lines (see Table 1).

CCDC reference: 1417923

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

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
C29H29O2ⁱ	0.93	2.39	3.293(3)	165
C6H6BO1ⁱⁱ	0.97	2.40	3.292(2)	154

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

Acknowledgments

The authors thank Dr Babu Varghese and SAIF, IIT Madras, for collection of the intensity data.

supplementary crystallographic information

S1. Comment

\ Acridine derivatives with a dihydropyridine unit belong to a special class of compounds, which are important because of their wide range of applications in the pharmaceutical and dye industries. They are also well known as therapeutic agents (Nasim & Brychcy, 1979; Thull & Testa, 1994).

In the title compound, Fig. 1, the bond lengths are close to those reported for similar compounds, for example 10-benzyl-9-(4-ethoxyphenyl)-3,3,6,6-tetramethyl-3,4,6,7,9,10-\ hexahydroacridine-1,8(2H,5H)-dione (Sughanya & Sureshbabu, 2012). In the dihydropyridine ring bonds C4–C5 and C1–C2 are double bonds as indicated by the bond distances (C4–C5 = 1.349 (2) Å and C1–C2 = 1.348 (2) Å), . The C5–C4–C9 [119.84 (18)°] and C1–C2–C15 [120.15 (17)°] angles are almost the same. The central dihydropyridine ring is almost planar with a mean deviation from the mean plane of 0.0509 (6) Å and with a maximum deviation of 0.0973 (3) Å for atom C3. The planar 3,4-dimethoxyphenyl and benzyl rings form dihedral angles of 89.47 (9)° and 82.90 (11)° with the dihydropyridine mean plane. Rings A (C4–C9), B (N1/C1—C5) and C (C1/C2/C12—C15) show total puckering amplitudes Q(T) of 0.469 (2) Å, 0.142 (1) Å and 0.484 (3) Å, respectively. The cyclohexenone rings A and C adopt envelope conformations, whereas the central ring B adopts a flattened boat conformation. This can be understood from the puckering parameters (Cremer & Pople, 1975): φ = 185.73 (2)° and θ = 58.67 (2)° (for A); φ = 0.3 (4)°, and θ = 111.1 (3)° (for B) and φ = 62.69 (2)°, θ = 120.98 (2)° (for C), respectively. In this conformation atoms C7 and C13 must be described as the flap atoms, being situated out of the plane of the respective rings with deviations of 0.3302 (2) Å and 0.3411 Å, respectively.

In the crystal, molecules are linked via a pair of C—H···O hydrogen bonds forming inversion dimers, which in turn are linked by C—H···O hydrogen bonds forming slabs lying parallel to (001); see Table 1 and Fig. 2

S2. Synthesis and crystallization

The title compound was prepared in two stages. In the first stage, a mixture of 3,4-dimethoxybenzaldehyde (0.83 g, 5 mmol), 5,5-dimethylcyclohexane-1,3-dione (dimedone) (1.40 g, 10 mmol) and 20 ml of ethanol was heated to 343 K for ca 10 min. The reaction mixture was allowed to cool to room temperature and the resulting solid intermediate, 2,2'-((3,4- dimethoxyphenyl) methylene)bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) was filtered and dried (m.p.: 411 - 413 K; yield: 96%). In the second stage, ca 1.0 g (2.4 mmol) of this intermediate was dissolved in 25 ml of acetic acid. The solution was refluxed together with benzylamine (0.33 g, 3 mmol) for 8 h with the reaction being monitored by TLC. After completion of the reaction, the reaction mixture was poured into crushed ice and stirred well. The solid that separated was filtered and dried and then recrystallized from ethanol to yield yellow crystals of the title compound (m.p.: 449 - 451 K; yield: 76%).

S3. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. All the H atoms were identified from difference electron density maps and subsequently treated as riding atoms: C—H = 0.93 - 0.98 Å with U_iso(H) = 1.5U_eq(C) for methyl H atoms and 1.2U_eq(C) for other H atoms.